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We aimed to perform a systematic review and network meta-analysis to evaluate the preventive strategies for preterm birth in twin-to-twin transfusion syndrome. PubMed, Embase and Cochrane Central were searched from inception to December 2023 with no filters. Additionally, the reference lists of the included studies were manually examined to identify any supplementary studies. We selected randomized controlled trials and cohorts comparing interventions to prevent preterm birth in twin pregnancies complicated by twin-to-twin transfusion syndrome. A random-effects frequentist network meta-analysis was performed using RStudio version 4.3.1. Randomized controlled trials and cohorts were assessed respectively using the Risk of Bias in Non-randomized Studies of interventions tool and Cochrane Collaboration's tool for assessing risk of bias in randomized trials. In this systematic review and meta-analysis, we included eight studies comprising a total of 719 patients. Compared with expectant management, cerclage stood out as the only intervention associated with an increase in the survival of at least one twin (risk ratio 1.12; 95 % confidence interval 1.01–1.23). Our subgroup analysis based on different thresholds for short cervix demonstrated a significant reduction in the risk of preterm birth before 32 weeks with ultrasound-indicated cerclage using a 15 mm criterion (risk ratio 0.65; 95 % confidence interval 0.47–0.92). Our study suggests the potential benefit of cerclage as a preventive strategy for preterm birth in pregnancies complicated by twin-to-twin transfusion syndrome. These findings highlight the necessity for further investigation to corroborate our results and address the optimal threshold for ultrasound-indicated cerclage. [ABSTRACT FROM AUTHOR]

Introduction: Our objective was to investigate the association between the presence of placental anastomoses and intertwin differences in renin‐angiotensin‐aldosterone activation in monochorionic twins using amniotic fluid aldosterone (AF‐ALD) levels. In addition, this study also examined the association between AF‐ALD and the ALD levels in the umbilical cord blood (UCB‐ALD) in monochorionic twins. Material and Methods: This prospective study included monochorionic diamniotic (MD) twin pregnancies that were not complicated by twin‐to‐twin transfusion syndrome (TTTS) at delivery. Amniotic fluid and umbilical cord vein blood samples were collected from each twin at delivery, and the ALD levels were measured subsequently. The MD twins were divided into two groups: those with placental anastomoses and those without anastomoses owing to fetoscopic laser surgery. The differences in the AF‐ALD levels between the larger and smaller twins were analyzed. Results: The AF‐ALD levels showed a strong and significant positive correlation with UCB‐ALD levels in 131 MD twins (r = 0.804, p < 0.001). Intertwin differences were examined in 41 and 28 pairs of MD twins with and without placental anastomoses, respectively. The AF‐ALD levels in the smaller twins were significantly higher than those in the larger twins among the pairs of MD twins with placental anastomoses (p = 0.003); however, no statistically significant intertwin differences were observed among the twins without placental anastomoses (p > 0.05). Conclusions: The AF‐ALD levels reflect the UCB‐ALD levels in MD twins. The presence of placental anastomoses led to intertwin discordance in the ALD levels in MD twins even uncomplicated with TTTS. It was considered that monochorionic twins have this clinical background, and it leads to the development of TTTS. [ABSTRACT FROM AUTHOR]

A major obstacle in applying machine learning for medical fields is the disparity between the data distribution of the training images and the data encountered in clinics. This phenomenon can be explained by inconsistent acquisition techniques and large variations across the patient spectrum. The result is poor translation of the trained models to the clinic, which limits their implementation in medical practice. Patient-specific trained networks could provide a potential solution. Although patient-specific approaches are usually infeasible because of the expenses associated with on-the-fly labeling, the use of generative adversarial networks enables this approach. This study proposes a patient-specific approach based on generative adversarial networks. In the presented training pipeline, the user trains a patient-specific segmentation network with extremely limited data which is supplemented with artificial samples generated by generative adversarial models. This approach is demonstrated in endoscopic video data captured during fetoscopic laser coagulation, a procedure used for treating twin-to-twin transfusion syndrome by ablating the placental blood vessels. Compared to a standard deep learning segmentation approach, the pipeline was able to achieve an intersection over union score of 0.60 using only 20 annotated images compared to 100 images using a standard approach. Furthermore, training with 20 annotated images without the use of the pipeline achieves an intersection over union score of 0.30, which, therefore, corresponds to a 100% increase in performance when incorporating the pipeline. A pipeline using GANs was used to generate artificial data which supplements the real data, this allows patient-specific training of a segmentation network. We show that artificial images generated using GANs significantly improve performance in vessel segmentation and that training patient-specific models can be a viable solution to bring automated vessel segmentation to the clinic. [ABSTRACT FROM AUTHOR]

To characterize the neonatal hemodynamic profiles in recipients born after twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic selective laser coagulation (FSLC). Retrospective analysis during the first month of life of recipient twins. Of the 480 newborns born during an 11-year period, 138 recipient twins with prenatal FSLC were classified into four groups: no hemodynamic impairment (NoHI, n = 102, 74%), isolated high blood pressure (HighBP, n = 18, 13%), right ventricular outflow tract obstruction (RVOTO, n = 10, 7%), and cardiac failure (CF, n = 8, 6%). The time (median (IQR)) between FSLC and birth was significantly shorter in the HighBP (36 days (23–54)) and CF (44 days (18–54)) groups than in the RVOTO (91 days (68–112)) and NoHi (82 days (62–104)) groups (p < 0.001). Conclusion: Four distinct and well-characterized groups of recipients were identified based on their hemodynamics. High blood pressure and heart failure occurred in approximately 20% of the infants and were associated with a time between laser coagulation and birth of less than 2 months. What is Known: • Twin-to-twin transfusion syndrome (TTTS) is characterized by a hemodynamic imbalance that leads to high fetal and neonatal mortality if left untreated. One-third of recipient twins born without prenatal fetoscopic laser coagulation (FSLC) develop a life-threatening cardiac failure. What is New: • Four distinct groups of recipient twins with prenatal FSLC have been identified based on their hemodynamics. High blood pressure and cardiac failure occurred in 20% of the infants and were associated with an interval between FSLC and birth of less than 2 months. [ABSTRACT FROM AUTHOR]

Purpose: In twin-to-twin transfusion syndrome (TTTS), abnormal vascular anastomoses in the monochorionic placenta can produce uneven blood flow between the two fetuses. In the current practice, TTTS is treated surgically by closing abnormal anastomoses using laser ablation. This surgery is minimally invasive and relies on fetoscopy. Limited field of view makes anastomosis identification a challenging task for the surgeon. Methods: To tackle this challenge, we propose a learning-based framework for in vivo fetoscopy frame registration for field-of-view expansion. The novelties of this framework rely on a learning-based keypoint proposal network and an encoding strategy to filter (i) irrelevant keypoints based on fetoscopic semantic image segmentation and (ii) inconsistent homographies. Results: We validate our framework on a dataset of six intraoperative sequences from six TTTS surgeries from six different women against the most recent state-of-the-art algorithm, which relies on the segmentation of placenta vessels. Conclusion: The proposed framework achieves higher performance compared to the state of the art, paving the way for robust mosaicking to provide surgeons with context awareness during TTTS surgery. [ABSTRACT FROM AUTHOR]

Objective To investigate fetal growth changes and predictive factors for selective fetal growth restriction (sFGR) in patients with twin-to-twin transfusion syndrome (TTTS) after fetoscopic laser coagulation (FLC). Methods This retrospective study included twin-pregnant women with fetal TTTS who underwent FLC at our institution between 2011 and 2020. Twin pairs who survived at least 28 days after FLC and at least 28 days after birth were included. A paired t-test was used to compare the mean discordance between the estimated fetal weights at the FLC and the birth weights. The predictive factors for sFGR after FLC were evaluated using univariate and multivariate logistic regression analyses. Results A total of 119 eligible pairs of patients who underwent FLC were analyzed. The weight percentile at birth significantly decreased after FLC in the recipients (53.7±30.4 percentile vs. 43.7±28.0 percentile; P

A fetoscope is an optical endoscope, which is often applied in fetoscopic laser photocoagulation to treat twin-to-twin transfusion syndrome. In an operation, the clinician needs to observe the abnormal placental vessels through the endoscope, so as to guide the operation. However, low-quality imaging and narrow field of view of the fetoscope increase the difficulty of the operation. Introducing an accurate placental vessel segmentation of fetoscopic images can assist the fetoscopic laser photocoagulation and help identify the abnormal vessels. This study proposes a method to solve the above problems. A novel encoder-decoder network with a dual-path structure is proposed to segment the placental vessels in fetoscopic images. In particular, we introduce a channel attention mechanism and a continuous convolution structure to obtain multi-scale features with their weights. Moreover, a switching connection is inserted between the corresponding blocks of the two paths to strengthen their relationship. According to the results of a set of blood vessel segmentation experiments conducted on a public fetoscopic image dataset, our method has achieved higher scores than the current mainstream segmentation methods, raising the dice similarity coefficient, intersection over union, and pixel accuracy by 5.80%, 8.39% and 0.62%, respectively. [ABSTRACT FROM AUTHOR]

Context Low birthweight (bw) and unfavorable intrauterine conditions have been associated with metabolic sequelae in later life, but little is known about their impact on glucocorticoid metabolism. Objective We studied monozygotic twins with intratwin bw differences to analyze the long-term impact of bw on glucocorticoid metabolism. Methods 46 monozygotic twin pairs with bw differences of <1 SDS (concordant; n = 29) and ≥1 SDS (discordant; n = 17) were recruited. At 6.9 years (mean age), saliva samples were collected (at 7 hours, 13 hours, 18 hours and 21 hour) and analyzed with liquid chromatography–tandem mass spectrometry (LC-MS/MS). Results We found significant or highly significant intratwin correlations in all twin pairs at 3 of 4 (cortisol), and 4 of 4 (cortisone) time points. Graphic evaluation of the diurnal cortisol patterns for each twin pair showed a distinct alignment in all groups. Analyses of the change of intratwin differences over the day by mixed linear modeling showed no intratwin differences in diurnal patterns. Regression analyses of intratwin differences at 7:00 hours showed a significant influence of catch-up growth, indicating lower cortisol concentrations in smaller twins with more catch-up growth (adj. R2 = 0.159, P =.014, ß = −3.71, F(1,42) = 9.15, f2 = 0.19). Conclusion In monozygotic twins with intratwin bw differences, intratwin catch-up growth showed a moderate influence on intratwin differences in morning cortisol concentrations. We observed no differences regarding diurnal patterns. In contrast, in all groups, we found significant intratwin correlations for cortisol and cortisone over the day and a pronounced graphic alignment of cortisol diurnal patterns. We therefore suggest a predominant significance of the genetic background compared with bw differences on cortisol metabolism. [ABSTRACT FROM AUTHOR]

With an increasing incidence of twin gestations, understanding the inherent risks associated with these pregnancies is essential in modern obstetrics. The unique differences in placentation in monochorionic twins leads to unique complications, including twin-to-twin transfusion syndrome, the twin anemia-polycythemia sequence, and selective fetal growth restriction. Not only does the understanding of the monochorionic placenta lead to an understanding of the pathophysiology of the complications of monochorionic twins, but it also has led to the development of highly effective directed fetal therapy via fetoscopic laser coagulation used in twin-to-twin transfusion syndrome. [ABSTRACT FROM AUTHOR]

Purpose: Fetoscopic laser photocoagulation of placental anastomoses is the most effective treatment for twin-to-twin transfusion syndrome (TTTS). A robust mosaic of placenta and its vascular network could support surgeons' exploration of the placenta by enlarging the fetoscope field-of-view. In this work, we propose a learning-based framework for field-of-view expansion from intra-operative video frames. Methods: While current state of the art for fetoscopic mosaicking builds upon the registration of anatomical landmarks which may not always be visible, our framework relies on learning-based features and keypoints, as well as robust transformer-based image-feature matching, without requiring any anatomical priors. We further address the problem of occlusion recovery and frame relocalization, relying on the computed features and their descriptors. Results: Experiments were conducted on 10 in-vivo TTTS videos from two different fetal surgery centers. The proposed framework was compared with several state-of-the-art approaches, achieving higher SSIM 5 on 7 out of 10 videos and a success rate of 93.25 % in occlusion recovery. Conclusion: This work introduces a learning-based framework for placental mosaicking with occlusion recovery from intra-operative videos using a keypoint-based strategy and features. The proposed framework can compute the placental panorama and recover even in case of camera tracking loss where other methods fail. The results suggest that the proposed framework has large potential to pave the way to creating a surgical navigation system for TTTS by providing robust field-of-view expansion. [ABSTRACT FROM AUTHOR]

Abstract Objectives To compare the clinical outcomes of different multifetal pregnancy reduction (MFPR) programs in dichorionic (DC) triplets, and explore the association between early ultrasound characteristics and co-twin death after potassium chloride (KCl) injection into one monochorionic (MC) twin. Methods We retrospectively reviewed the data of DC triplets who underwent MFPR at our center during 2012–2021. Patients were grouped as follows: intracardiac KCl injection into one MC twin (group A), intracardiac KCl injection into both MC twins simultaneously (group B), and reduction of the singleton fetus (group C) and pregnancy outcomes were compared. Logistic regression was used to determine whether ultrasound measurements at 11–13+6 weeks predicted co-twin death and the receiver operator characteristic (ROC) analysis was conducted to assess the predictive performance. Results Finally, we enrolled 184 patients. 153 cases were in group A, and 18, 13 cases were in group B and C respectively. Gestational age at the time of MFPR did not differ among the 3 groups (median: $$12^\frac67$$ 12 6 7 weeks). The survival rate was 89.6%, 88.9%, and 92.3% in group A, B, and C respectively, which was comparable among groups. Preterm birth was more common in group C (10/12, 83.3%). After KCl injection into one MC twin, co-twin death occurred in 86.3% cases (132/153) within 1 day; however, 3 patients had 2 live births each, with normal postnatal development. Intertwin nuchal translucency (NT) difference/discordance significantly predicted co-twin death within 1 day after MFPR, and the areas under the ROC curve were 0.694 and 0.689, respectively. Conclusions For MFPR in DC triplet pregnancies, reduction of the MC twins results in less preterm birth, and women with KCl injection into either one or both MC twins had similar outcomes. Large intertwin NT difference/discordance was associated with co-twin death within 1 day after KCl injection into one of the MC twins.

Objective To report the experiences of triplet pregnancies complicated by twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic laser coagulation at a single center. Methods Herein, we conducted a retrospective analysis to investigate the management and perinatal outcomes of triplet pregnancies with TTTS treated at a single institution between 2017 and 2022. Results Seven of the 98 triplet pregnancies (7.1%) encountered were complicated by TTTS, and all were dichorionic triamniotic triplets. Of the seven triplet pregnancies complicated by TTTS, four were treated with fetoscopic laser coagulation at our center, at a median gestational age of 20 weeks. No procedure-related complications or maternal complications were observed. The survival rate was higher and perinatal outcomes were better in fetoscopic laser coagulation cases than in other management cases. Four donor and four recipient triplets survived, with a median gestational age of 33 weeks at delivery. Although there were no cases of poor neonatal outcomes, one case was diagnosed with white matter injury, suspected to be hypoxic-ischemic encephalopathy on postnatal investigation. Conclusion Fetoscopic laser coagulation is a feasible treatment option for triplet TTTS, provided the attending specialists have extensive experience with this technique.

Abstract Background Pulmonary stenosis (PS) is a congenital heart diseases (CHDs) with a spectrum of stenosis. Monochorionic (MC) twins are at increased risk of CHDs, especially acquired CHDs in twin-twin transfusion syndrome (TTTS). PS/Pulmonary atresia (PA) is a rare coincidence with TTTS. MC twin pregnancies have increased in last decades due to increasing in maternal age and extensive use of assisted reproductive technologies. Therefore, attention to this group is important for heart abnormalities, especially in twins with TTTS. Multiple cardiac abnormalities in MC twins with TTTS are to be expected due to cardiac hemodynamic changes and may be eliminated by Fetoscopic laser photocoagulation treatment. Prenatal diagnosis of PS is necessary given the importance of treatment after birth. Case presentation We here present a case of coexistence of TTTS with PS in a growth restricted recipient twin who successfully treated with balloon pulmonary valvuloplasty in neonatal period. Also, we detected infundibular PS after valvuloplasty that treated with medical therapy (propranolol). Conclusions It is important to detect acquired cardiac abnormalities in MC twins with TTTS, and follow them up after birth to determine the need of intervention in neonatal period.

Objectives: To compare the clinical outcomes of different multifetal pregnancy reduction (MFPR) programs in dichorionic (DC) triplets, and explore the association between early ultrasound characteristics and co-twin death after potassium chloride (KCl) injection into one monochorionic (MC) twin. Methods: We retrospectively reviewed the data of DC triplets who underwent MFPR at our center during 2012–2021. Patients were grouped as follows: intracardiac KCl injection into one MC twin (group A), intracardiac KCl injection into both MC twins simultaneously (group B), and reduction of the singleton fetus (group C) and pregnancy outcomes were compared. Logistic regression was used to determine whether ultrasound measurements at 11–13+6 weeks predicted co-twin death and the receiver operator characteristic (ROC) analysis was conducted to assess the predictive performance. Results: Finally, we enrolled 184 patients. 153 cases were in group A, and 18, 13 cases were in group B and C respectively. Gestational age at the time of MFPR did not differ among the 3 groups (median: 12 6 7 weeks). The survival rate was 89.6%, 88.9%, and 92.3% in group A, B, and C respectively, which was comparable among groups. Preterm birth was more common in group C (10/12, 83.3%). After KCl injection into one MC twin, co-twin death occurred in 86.3% cases (132/153) within 1 day; however, 3 patients had 2 live births each, with normal postnatal development. Intertwin nuchal translucency (NT) difference/discordance significantly predicted co-twin death within 1 day after MFPR, and the areas under the ROC curve were 0.694 and 0.689, respectively. Conclusions: For MFPR in DC triplet pregnancies, reduction of the MC twins results in less preterm birth, and women with KCl injection into either one or both MC twins had similar outcomes. Large intertwin NT difference/discordance was associated with co-twin death within 1 day after KCl injection into one of the MC twins. [ABSTRACT FROM AUTHOR]

This work explores the feasibility of simultaneous and continuous intra-abdominal, intra-uterine, and arterial blood pressure measurements to examine the hemodynamic perturbation expected during therapeutic amnioreduction and to better understand the protective role of the placenta during that treatment. Patients with twin-to-twin transfusion syndrome were treated with fetoscopic laser ablation followed by amnioreduction. Intra-abdominal, intra-uterine, and mean arterial pressures were simultaneously recorded during amnioreduction performed in steps of 200 mL. Placental thickness and uterine dimensions were measured before and after amnioreduction by ultrasonography. Useful pressure recordings were obtained between volume reduction steps and short hands-off periods in four studies. Median amnioreduction volume was 1400 mL corresponding to a median uterine volume reduction of 1121 mL. Mean intra-uterine pressure significantly fell from 24.8 to 13.6 mmHg (p = 0.011) and intra-abdominal pressure significantly decreased from 13.4 to 9.2 mmHg after amnioreduction (p = 0.015). Uterine pressure recordings revealed transient contractions (A , in mmHg) following individual amnioreduction steps, which increased with fractional amnioreduction (F , no dimension) (A = 17.23* F + 11.81; r = 0.50, p = 0.001). Simultaneous and continuous measurement of intra-abdominal, intra-uterine, and arterial blood pressures during amnioreduction is feasible. The dynamics reveal transient uterine contractions reaching levels comparable to those seen during childbirth which seem to oppose impending maternal hypovolemia by placental steal at the expense of temporarily reducing placental perfusion pressure and underline the importance of uterine and placental interaction. [Display omitted] • Continuous intra-uterine and intra-abdominal pressure recordings are feasible. • Amnioreduction induces uterine contractions increasing intra-uterine pressure. • Magnitude of uterine contractions increases with the extent of amnioreduction. • Uterine contractions may have a protective effect against placental blood 'steal'. [ABSTRACT FROM AUTHOR]

Computer-assisted technologies have made significant progress in fetoscopic laser surgery, including placental vessel segmentation. However, the intra- and inter-procedure variabilities in the state-of-the-art segmentation methods remain a significant hurdle. To address this, we investigated the use of conditional generative adversarial networks (cGANs) for fetoscopic image segmentation and compared their performance with the benchmark U-Net technique for placental vessel segmentation. Two deep-learning models, U-Net and pix2pix (a popular cGAN model), were trained and evaluated using a publicly available dataset and an internal validation set. The overall results showed that the pix2pix model outperformed the U-Net model, with a Dice score of 0.80 [0.70; 0.86] versus 0.75 [0.0.60; 0.84] (p-value < 0.01) and an Intersection over Union (IoU) score of 0.70 [0.61; 0.77] compared to 0.66 [0.53; 0.75] (p-value < 0.01), respectively. The internal validation dataset further validated the superiority of the pix2pix model, achieving Dice and IoU scores of 0.68 [0.53; 0.79] and 0.59 [0.49; 0.69] (p-value < 0.01), respectively, while the U-Net model obtained scores of 0.53 [0.49; 0.64] and 0.49 [0.17; 0.56], respectively. This study successfully compared U-Net and pix2pix models for placental vessel segmentation in fetoscopic images, demonstrating improved results with the cGAN-based approach. However, the challenge of achieving generalizability still needs to be addressed. [ABSTRACT FROM AUTHOR]

Purpose: Fetoscopic laser coagulation for twin-to-twin transfusion syndrome is challenging for anterior placenta due to the rigidity of current tools. The capacity to keep entry port forces minimal is critical for this procedure, as is optimal coagulation distance and orientation. This work introduces technological tools to this end. Methods: A novel fetoscope is presented with a rigid shaft and a flexible steerable segment at the distal end. The steerable segment can bend up to 90 ∘ even when loaded with a laser fiber. An artificial pneumatic muscle makes such acute bending possible while allowing for a low-weight and disposable device. Results: The flexible fetoscope was validated in a custom-made phantom model to measure visual range and coagulation efficacy. The flexible fetoscope shows promising results when compared to a clinical rigid curved fetoscope to reach anterior targets. The new fetoscope was then evaluated in vivo (pregnant ewe) where it successfully coagulated placental vasculature. Conclusion: The flexible fetoscope improved the ability to achieve optimal coagulation angle and distance on anteriorly located targets. The fetoscope also showed the potential to lead fetoscopic laser coagulation and other fetal surgical procedures toward safer and more effective interventions. [ABSTRACT FROM AUTHOR]

Background. Much controversy surrounds the estimation of anthropometric parameters in multiple newborns. In newborn monochorionic diamniotic twins, these parameters can be affected by specific antenatal complications.Objectives. To estimate the physical development parameters of preterm monochorionic diamniotic twins according to standards proposed within the INTERGROWTH-21st project, taking specific intrauterine complications into account.Methods. The anthropometric data were analyzed in 148 pairs of newborn monochorionic diamniotic twins, who were divided into three groups according to the presence of specific intrauterine complications: Group I (n = 56 pairs) — twin-to-twin transfusion syndrome (TTTS); Group II (n = 38 pairs) — selective intrauterine growth restriction (sIUGR); Group III (n = 58 pairs) — absence of the above-mentioned specific complications. The obtained data were statistically processed on a personal computer via variation statistics methods using Microsoft Excel spreadsheets (Microsoft, USA) and an online service available at https://medstatistic.ru.Results. Newborns with sIUGR (37–100.0%) and 26 (49.1%) donors fell into the category of newborns light for gestational age. Disharmonious (3–10th percentile) and markedly disharmonious (below the 3rd percentile) physical development at birth was most commonly observed in newborns with sIUGR and, to a lesser extent, in donors (OR — 9.2; 95% CI — 3.2–24.3; p < 0.05), which was noted only occasionally in monochorionic twins from other groups. A combined decrease in the values of birth centiles for head circumference, body weight, and body length was found in 13 (35.1%) newborns with sIUGR and in 12 (22.6%) donors, which may mark the severity of antenatal complications and the development of neurological deficit.Conclusion. Monochorionic diamniotic twins include newborns having greater and lower body weights. In the newborn having a lower birth weight, specific complications associated with monochorionic multiple pregnancy result in body weight and length deficit, disharmonious development due to the lack of nourishment (22.6% in the TTTS group and 73.0% in the sIUGR group), as well as delayed head circumference growth in 56.8% of newborns with sIUGR.

Pregnancy is a state of emergency for most women and is usually a great happiness. Twin pregnancy should bring double happiness. Unfortunately, it often means more problems, more research, more worries. TTTS is a twin-to-twin transfusion syndrome that carries many complications.It occurs in 5-25% of monochorionic twin pregnancies. The severity of the disease is determined using the Quintero scale. The methods of treatment include fetoscopic laser photocoagulation, expectant management, amnioreduction, termination of pregnancy, usually when the fetal lungs are mature. The prognosis depends on many factors, including the type of vascular anastomoses. There are two types of TTTS: acute and chronic.

Background: Pulmonary stenosis (PS) is a congenital heart diseases (CHDs) with a spectrum of stenosis. Monochorionic (MC) twins are at increased risk of CHDs, especially acquired CHDs in twin-twin transfusion syndrome (TTTS). PS/Pulmonary atresia (PA) is a rare coincidence with TTTS. MC twin pregnancies have increased in last decades due to increasing in maternal age and extensive use of assisted reproductive technologies. Therefore, attention to this group is important for heart abnormalities, especially in twins with TTTS. Multiple cardiac abnormalities in MC twins with TTTS are to be expected due to cardiac hemodynamic changes and may be eliminated by Fetoscopic laser photocoagulation treatment. Prenatal diagnosis of PS is necessary given the importance of treatment after birth. Case presentation: We here present a case of coexistence of TTTS with PS in a growth restricted recipient twin who successfully treated with balloon pulmonary valvuloplasty in neonatal period. Also, we detected infundibular PS after valvuloplasty that treated with medical therapy (propranolol). Conclusions: It is important to detect acquired cardiac abnormalities in MC twins with TTTS, and follow them up after birth to determine the need of intervention in neonatal period. [ABSTRACT FROM AUTHOR]

Fetoscopic laser photocoagulation is used to treat twin-to-twin transfusion syndrome; however, this procedure is hindered because of difficulty in visualising the intraoperative surgical environment due to limited surgical field-of-view, unusual placenta position, limited manoeuvrability of the fetoscope and poor visibility due to fluid turbidity and occlusions. Fetoscopic video mosaicking can create an expanded field-of-view image of the fetoscopic intraoperative environment, which could support the surgeons in localising the vascular anastomoses during the fetoscopic procedure. However, classical handcrafted feature matching methods fail on in vivo fetoscopic videos. An existing state-of-the-art method on fetoscopic mosaicking relies on vessel presence and fails when vessels are not present in the view. We propose a vessel-guided hybrid fetoscopic mosaicking framework that mutually benefits from a placental vessel-based registration and a deep learning-based dense matching method to optimise the overall performance. A selection mechanism is implemented based on vessels' appearance consistency and photometric error minimisation for choosing the best pairwise transformation. Using the extended fetoscopy placenta dataset, we experimentally show the robustness of the proposed framework, over the state-of-the-art methods, even in vessel-free, low-textured, or low illumination non-planar fetoscopic views. [ABSTRACT FROM AUTHOR]

Introduction: A proportion of monochorionic diamniotic (MCDA) twin pregnancies complicated by twin-to-twin transfusion syndrome (TTTS) can present after 26 weeks of gestation. The aim of this study was to compare perinatal outcomes of late TTTS treated by fetoscopic laser coagulation versus traditional management with amniodrainage and/or emergency preterm cesarean delivery (CD). Methods: Retrospective cohort from January 2012 to January 2023 of consecutive MCDA twin pregnancies complicated by TTTS after 26 weeks and evaluated in our referring centers. We analyzed perinatal outcomes of cases treated with fetoscopic laser surgery at our national referral fetal surgery center in Queretaro, Mexico, and compared them with those managed with traditional management (amniodrainage and/or emergency preterm CD). The primary outcome was survival at discharge and the secondary outcome was gestational age (GA) at birth. Results: Among the study population, 46 TTTS cases were treated by fetoscopy at 27+6 (26+0–31+0) weeks+days and were compared with a group of 39 cases who underwent emergency preterm CD. In comparison to the group who underwent traditional management, the group treated by laser fetoscopy showed a significantly higher GA at birth (32+3 vs. 29+1 weeks+days, p < 0.001), lower frequency of preterm delivery below 37 weeks (91.3% vs. 100%, p = 0.06), 34 weeks (63.0% vs. 100%, p < 0.001), 32 weeks (50% vs. 74.4%, p = 0.02), or 30 weeks (28.3% vs. 53.8%, p = 0.01), and significantly higher perinatal survival (89.1% vs. 71.8%, p < 0.05 of at least one twin; and 65.2% vs. 38.5%, p = 0.01 of both twins, respectively). Conclusion: MCDA twins complicated with TTTS can be treated with fetoscopic laser surgery between 26 and 31 weeks of gestation, which is a feasible and safe option, and such cases are associated with a higher GA at birth and better perinatal survival than those managed with amniodrainage and/or emergency preterm CD. [ABSTRACT FROM AUTHOR]

To review current international clinical guidelines on the antenatal and intrapartum management of twin pregnancies, examining areas of consensus and conflict. We conducted a database search using Medline, Pubmed, Scopus, Academic Search Complete, CINAHL and ERCI Guidelines website. Guidelines were screened for eligibility using our inclusion and exclusion criteria. Those deemed eligible were quality assessed using the AGREE II tool and relevant data was extracted. We identified 21 relevant guidelines from 16 countries including two international society guidelines. There was consensus in determination of chorionicity and amnionicity within the first trimester, fetal anomaly scan between 18 and 22 weeks and the recommended screening for twin-to-twin transfusion syndrome (TTTS). For those that provided intrapartum guidance, there was agreement in recommending caesarean section to deliver monochorionic monoamniotic (MCMA) twins, epidural anaesthesia for intrapartum analgesia and the use of cardiotocography (CTG) for intrapartum fetal monitoring. The main areas of conflict included cervical length screening, frequency of ultrasound surveillance, timing of delivery of dichorionic twin pregnancies and circumstances for recommending vaginal delivery. There was a lack of advice on intrapartum management. This review has highlighted the need for unified international guidance on the management of twin pregnancy. Comparisons of current guidance demonstrates a lack of confidence in the management of labour in twin pregnancies. Further evidence on intrapartum care of twin pregnancies is needed to inform practice guidelines and improve both short and long term maternal and fetal outcomes. [ABSTRACT FROM AUTHOR]

Nowadays, the management and delivery of multiple pregnancies in the era of increased rate of multiple pregnancies is essential in work of an obstetrician-gynecologist. However, it is an ultrasound scanning that becomes a starting point to choose management strategies for multiple pregnancies. Despite tremendous advances in understanding the pathogenesis of developing specific complications, multiple pregnancies still account for a large proportion of perinatal complications. Therefore, continuously improving knowledge in antenatal diagnostics, the principles of prenatal care and optimal approach to delivery is fundamental for reducing morbidity and mortality rate related to multiple pregnancies.

Introduction: Chorioamniotic membrane separation (CAS), preterm prelabor rupture of membranes (PPROM), and preterm delivery (PTD) remain as major complications of fetoscopic laser photocoagulation (FLP) for twin-to-twin transfusion syndrome (TTTS). We sought to examine whether use of Quincke-tip needles for initial entry during FLP reduces the risk of these complications. Methods: This is a secondary analysis of prospectively collected data from patients that had FLP for TTTS at a single tertiary care center (2011–2021). We excluded patients for whom direct trocar entry was used. Patients for whom a Quincke-tip needle was used were compared to those for whom a diamond-tip needle was used during Seldinger entry. Demographics, ultrasound findings and operative characteristics were compared between groups. Postoperative outcomes and complications (including CAS, PPROM, and PTD) were also compared. Multivariate logistic regression models were fit to assess independent risk factors for complications. Results: 386 patients met inclusion criteria; Quincke-tip needles were used in 81 (21.0%) cases, while diamond-tip needles were used in 305 (79.0%). Rates of CAS (11.1 vs. 9.5%, p = 0.67) and PPROM (44.4 vs. 41.0%, p = 0.57) were similar between groups. Patients in the Quincke-tip group delivered 1.5 weeks earlier than those in the diamond-tip group (30.5 vs. 32.0 weeks, p = 0.01). However, these patients were more likely to be delivered for maternal (35.9 vs. 19.0%) and fetal (23.1 vs. 15.3%) indications (p < 0.01). In multivariate analysis, needle type was not identified as an independent risk factor for PPROM. However, Quincke-tip needle use was associated with PTD less than 32 weeks (aOR 1.74, 95% CI: 1.02–2.97, p = 0.043). Conclusion: Membrane complications following FLP were not associated with the needle type used for entry. Earlier delivery in the Quincke-tip group was likely attributable to higher rates of delivery for maternal and fetal indications, and not membrane complications. The needle chosen for entry is likely best determined by operator preference. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study was to evaluate the within-pair difference in retinopathy of prematurity (ROP) between donors and recipients with twin-to-twin transfusion syndrome (TTTS) and to identify risk factors for ROP development. Methods: This retrospective cohort study included 147 TTTS twin pairs managed between 2002 and 2022 and eligible for ROP screening. Primary outcomes were any stage ROP and severe ROP. Secondary outcomes were hemoglobin at birth, red blood cell transfusions, mechanical ventilation days, postnatal steroids, and neonatal morbidity. Donor status was defined as having polyhydramnios pre-laser. Results: Rates of any stage ROP (23% vs. 14%) and severe ROP (8% vs. 3%) were significantly higher in donors compared to recipients. Donors received a higher number of blood transfusions (1 [±1.9] versus 0.7 [±1.5]). Five factors were univariately associated with any stage ROP: donor status (odds ratio [OR] 1.9; 95% CI 1.3–2.9), lower gestational age (GA) at birth (OR 1.7; 95% CI 1.4–2.1), small for GA (OR 2.1; 95% CI 1.3–3.5), mechanical ventilation days (OR 1.1; 95% CI 1.1–1.2), and blood transfusions in phase 1 (OR 2.3; 95% CI 1.2–4.3). Three factors were independently associated with any stage ROP: donor status (OR 1.8; 95% CI 1.1–2.9), lower GA at birth (OR 1.6; 95% CI 1.2–2.1), and mechanical ventilation days (OR 1.1, 95% CI 1.0–1.1). Donor status was univariately associated with severe ROP (OR 2.3, 95% CI 1.1–5.0). Conclusion: Any stage ROP and severe ROP are detected twice as frequently in donors compared to recipients. Increased awareness for ROP is needed in donors, especially those with lower GA at birth and longer duration of mechanical ventilation. [ABSTRACT FROM AUTHOR]

Objective To evaluate the feasibility and clinical value of fetal left modified myocardial performance index (Mod-MPI) in assessment and management of prenatal twin anemia polycythemia sequence (TAPS). Methods We retrospectively reviewed fetuses with TAPS diagnosed prenatally between 2015 and 2019 at Asan Medical Center. Doppler ultrasound evaluation including the peak systolic velocity (PSV) of the middle cerebral artery (MCA) and fetal echocardiography including left Mod-MPI were evaluated and followed up after antenatal management. Results Among 10 cases of fetal twin pregnancies with prenatal TAPS, six were spontaneous and four were post-laser TAPS. Left Mod-MPI was abnormal in one or both twins of nine cases (90%) including all post-laser TAPS (n = 4) and 83.3% of spontaneous TAPS (n = 5). Three recipients, one donor and three former recipients/new donors had elevated left Mod-MPI values, and one donor, one recipient, two former donors/new recipients had decreased values. Antenatal intervention was performed in eight cases with intrauterine transfusion (n = 4), fetoscopic laser surgery (n = 2), radiofrequency ablation (n = 1), and intrauterine transfusion followed by radiofrequency ablation (n = 1). The remaining two cases were either delivered or managed expectantly. MCA-PSV and left Mod-MPI became normal on the follow-up scans in all cases except the delivered case. There were four fetal deaths: two occurred spontaneously and two were selectively terminated by radiofrequency ablation. Overall perinatal survival per fetus was 80% (16/20) and the median gestational age at delivery was 34.4 (range, 29.2–37.4) weeks. Neither postnatal death nor neurodevelopmental delay occurred during a median follow-up of 13 months (range, 0.25–60 months). Conclusion Fetal left Mod-MPI was useful for assessment of compromised fetal cardiac function in cases with prenatal TAPS. Application of fetal left Mod-MPI in prenatal staging of TAPS might help evaluate the severity of TAPS and decide timely antenatal intervention. [ABSTRACT FROM AUTHOR]

Introduction: Twin anemia-polycythemia sequence (TAPS) is a complication in monochorionic-diamniotic (MCDA) twin pregnancies. This study analyzes whether the prenatal diagnosis using delta middle cerebral artery-peak systolic velocity (MCA-PSV) > 0.5 multiples of the median (MoM) (delta group) detects more TAPS cases than the guideline-based diagnosis using the MCA-PSV cut off levels of >1.5 and <1.0 MoM (cut-off group), in a heterogenous group of MCDA twins. Methods: A retrospective analysis of 348 live-born MCDA twin pregnancies from 2010 to 2021 with available information on MCA-PSV within one week before delivery and hemoglobin-values within 24 h postnatally were considered eligible. Results: Among postnatal confirmed twin pairs with TAPS, the cut-off group showed lower sensitivity than the delta group (33% vs. 82%). Specificity proved higher in the cut-off group with 97% than in the delta group at 86%. The risk that a TAPS is mistakenly not recognized prenatally is higher in the cut-off group than in the delta group (52% vs. 18%). Conclusions: Our data shows that delta MCA-PSV > 0.5 MoM detects more cases of TAPS, which would not have been diagnosed prenatally according to the current guidelines. In the collective examined in the present study, TAPS diagnostics using delta MCA-PSV proved to be a more robust method. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the survival of twin-to-twin transfusion syndrome (TTTS) and concomitant twin anemia polycythemia sequence (TAPS) compared to TTTS without TAPS at the time of fetoscopic laser photocoagulation (FLP).Methods: TTTS pregnancies undergoing FLP were divided to three groups including (i) traditional TAPS definition of middle cerebral artery (MCA) peak systolic velocity (PSV) < 1 multiple of the median (MoM) in recipient and > 1.5 MoM in the donor fetus, (ii) delta MCA-PSV > 0.5 MoM and (iii) delta MCA-PSV > 1.0 MoM.Results: A total of 353 monochorionic twins underwent FLP for TTTS. Based on the traditional definition, 335 (94.9 %) had TTTS only and 18 (5.1 %) had TTTS + TAPS. There were 245 (69.4 %) TTTS only and 108 (30.6 %) TTTS + TAPS considering delta MCA-PSV > 0.5 MoM and 339 (96 %) TTTS only and 14 (4 %) TTTS + TAPS considering delta MCA-PSV > 1.0 MoM. No significant differences in survival were noted at birth or 30-days after delivery between TTTS and TTTS with TAPS patients using the traditional definition, delta > 0.5 MoM or delta > 1.0 MoM.Conclusion: The rate of neonatal survival at birth or at 30-days of life following FLP for TTTS only and TTTS with TAPS were not different based on any of the clinically used TAPS definitions. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effect of gestational age at laser therapy for twin‐to‐twin transfusion syndrome (TTTS) on perinatal outcome. Design and settings: Single retrospective observational cohort. Population All consecutive pregnancies affected by TTTS and referred to our department between January 2013 and August 2020. Methods: Gestational age was modelled both as a categorical and as a continuous variable. Log‐binomial regression was used to estimate the odds ratios (crude and adjusted for placental location, Quintero stage and cervical length) as well as the adjusted predicted probability of survival and fetal loss according to gestational age at laser therapy. Main outcomes: Fetal and neonatal survival, preterm prelabour rupture of membranes (PPROM). Results: Of the 503 pregnancies referred for TTTS, 431 were treated by laser therapy. Gestational age at laser therapy was positively and significantly associated with the overall survival at birth and at discharge (adjusted odds ratio [aOR] 1.12, 95% CI 1.05–1.19), as with a reduction in double fetal loss (aOR 0.81, 95% CI 0.71–0.92). Conversely, the rate of PPROM before 24 weeks was significantly higher in early cases (32% of PPROM <24 weeks when laser therapy was performed before 17 weeks versus 1.5% after 22 weeks, p < 0.001, aOR 0.60, 95% CI 0.48–0.72). Among the survivors, preterm birth before 28 weeks was significantly related to the gestational age at laser (OR 0.91, 95% CI 0.84–0.99), resulting in a significant impact on neonatal morbidity (OR 0.91, 95% CI 0.85–0.97). Conclusion: Our results suggest a significant and independent impact of the gestational age at laser surgery on perinatal survival, PPROM and neonatal morbidity. Gestational age at laser therapy for TTTS is associated with an increased risk of perinatal mortality and mortality. Linked article: This article is commented on by Mariano Lanna, pp. 2038 in this issue. To view this mini commentary visit https://doi.org/10.1111/1471‐0528.17237 [ABSTRACT FROM AUTHOR]

To explore differences among placental anastomoses, territory discordance, and umbilical cord insertion of twin-to-twin transfusion syndrome (TTTS) with and without selective intrauterine growth restriction (sIUGR). This study retrospectively analyzed 57 patients with TTTS who received conservative treatment and finally delivered at the Department of Obstetrics and Gynecology of Peking University Third Hospital from April 2014 to April 2019. Nine of the patient's placentas were too broken to finish the perfusion, and 48 were kept for graph analysis after perfusion. Among the 48 placentas, there were 17 in the TTTS with sIUGR group and 31 in the TTTS without sIUGR group. Differences in the placentas were compared between groups. The birth weight discordance ratio in the sIUGR group was significantly higher than that in the non-sIUGR group (0.41 ± 0.20 vs 0.24 ± 0.15, p =.001). The prevalence of thick artery-artery (AA) anastomoses in the sIUGR group was significantly higher than that in the non-sIUGR group (35.3% vs 6.5%, p =.017). The placental territory discordance ratio in the sIUGR group was significantly higher than that in the non-sIUGR group (0.40 [0.05, 0.86] vs 0.25 [0.02, 0.67], p =.024). The prevalence of velamentous cord insertion in the sIUGR group was significantly higher than that in the non sIUGR group (35.3% and 6.5%, p =.017). Placental territory discordance and velamentous umbilical cord insertion may be causes of TTTS with sIUGR. Compared with TTTS without sIUGR, TTTS with sIUGR had a higher prevalence of protective AA anastomoses in the placenta. [ABSTRACT FROM AUTHOR]

Background: This paper's intent is to describe the neonatal hemodynamic characteristics of recipient twins of monochorionic pregnancies complicated with twin-to-twin transfusion syndrome (TTTS), born without prenatal fetoscopic selective laser coagulation (FSLC). Methods: Retrospective analysis of hemodynamic characteristics was performed during the first five days of life of recipient twins from untreated TTTS. Results: Forty-two recipient twins were included and divided into three groups: no hemodynamic impairment (NoHI) (n = 15, 36%), isolated high blood pressure (HighBP) (n = 12, 28%), and cardiac failure group (CF) (n = 15, 36%). Patients of both CF and HighBP groups had high systolic blood pressure during the first 12 h of life and ventricular hypertrophy at early echocardiography. Cardiac failure occurred at a median age of 14 h (IQR = 6–24) and was followed by a drop in systolic and diastolic blood pressure. Acute kidney injury was more frequent (93% vs. 25%, p < 0.001) and severe (p <0.001) in the CF group than in the HighBP group. The mortality rate in the CF group was 40%. Factors associated with CF were twin anemia-polycythemia sequence (p = 0.012), very preterm birth (p = 0.040), and polycythemia (p = 0.002). Conclusion: One-third of recipient twins born without prenatal FSLC developed life-threatening cardiac failure during the first 24 h of life. [ABSTRACT FROM AUTHOR]

Twin‐to‐twin transfusion syndrome (TTTS) is a severe disorder that often leads to the death of monochorionic twin fetuses, if left untreated. Current prenatal interventions to treat the condition involve the use of rigid fetoscopes for targeted laser coagulation of the vascular anastomoses. These tools are limited in their area of operation, making treatment challenging, especially in cases with anterior placentation. Herein, a robotic platform to perform this task using remote magnetic navigation is proposed. In contrast to rigid tools, the presented custom magnetic fetoscope is highly flexible, dexterous, and has considerable advantages, including safety and precision. A visual servoing algorithm that allows the surgeon to navigate in the uterus with submillimeter precision is introduced. The system has been validated on ex vivo human placentas in a setting that mimics the real intraoperative conditions. [ABSTRACT FROM AUTHOR]

Abstract Background Right ventricular outflow tract obstruction (RVOTO) is the most frequently encountered congenital heart disease in patients with twin –twin transfusion syndrome (TTTS) and is especially prevalent in the recipient twin. In this retrospective study, we evaluated the incidence, prognosis, postnatal management, and perinatal outcomes of and risk factors for RVOTO in the recipient twin in severe TTTS cases which diagnosed before 26 weeks after fetoscopic laser photocoagulation (FLP) at a single center in Taiwan. Methods RVOTO was diagnosed using fetal or postnatal echocardiography. The fetal outcomes evaluated were perinatal survival rate, neonatal brain image anomalies rate, gestational age at delivery, and birth weight. Results Total 187 severe TTTS cases were included; 14 (7.49%) had a recipient twin with RVOTO (12 cases of pulmonary stenosis and 2 of pulmonary atresia). Of these 14 cases, 3 (21.4%) demonstrated improvements in outflow obstruction after FLP, and 11 (78.6%) resulted in perinatal survival. Of the 11 survivors, 5 (45.5%) received transcatheter balloon valvuloplasty to alleviate the RVOTO. The perinatal survival rate, gestational age at delivery, neonatal brain image anomaly rate, and birth weights did not significantly differ between the groups in which the recipient twin had versus did not have RVOTO. Generally, the recipient twin had RVOTO received FLP at a younger gestational age (in weeks; 19.3 ± 2.4 vs. 20.7 ± 2.6, p = 0.048) and had a higher percentage of cases at Quintero stage IV (50.0% vs. 12.1%, p < 0.001) than those in which the recipient twin did not have with RVOTO. Using logistic regression, we discovered that FLP at a younger gestational age (p = 0.046, odds ratio = 0.779) and TTTS at Quintero stage IV (p = 0.001, odds ratio = 7.206) were risk factors for the recipient twin developing RVOTO after FLP in severe TTTS cases. Conclusions The post-FLP perinatal outcomes of cases of severe TTTS in which the recipient twin had versus did not have RVOTO were comparable in this study, which may have been due to the similar gestational ages at delivery and strong influence of high Quintero stages (stages III and IV).

Abstract Background In utero limb ischemia is a rare complication of the monochorionic twin pregnancies complicated with twin to twin transfusion syndrome (TTTS). The condition is more often seen in recipient twins. There are few theories of the pathogenesis including in utero venous thromboembolism, but the cause remains unclear. However, limb ischemia is thought to be unrelated with any prenatal intervention. Case Presentation We present a case of a monochorionic twin pregnancy complicated with TTTS admitted to the Clinic for selective fetoscopic laser photocoagulation. The invasive procedure failed due to poor visibility. In the following weeks of pregnancy, amnioreduction procedures were performed. At 28 weeks of gestation due to twin anemia-polycythemia sequence diagnosis the patient was qualified for cesarean section. Postnatally, the donor twin was diagnosed with lower right limb ischemic necrosis. The extremity was amputated 2 days later with an uncomplicated recovery. After speculations of the potential pathogeneses it was suggested that the ischemic limb occurred as a complication of the main condition – TTTS. Conclusions In literature, there have been no cases reported of TTTS stage I complicated with donor twin limb ischemia. The actual cause of the in utero limb ischemic necrosis in monochorionic twins remains unknown. Nevertheless, increased attention to the potential complication after failed invasive procedures or conservative treatment should be required.

Low birthweight may have adverse sequelae in later life. Therefore, we analyzed behavioral difficulties and salivary glucocorticoid profiles in monozygotic twins with intra-twin birthweight differences due to twin-to-twin transfusion syndrome (TTTS). 46 monozygotic TTTS twin pairs with birthweight differences of <1SDS (concordant; n=29) and ≥1SDS (discordant; n=17) were recruited at a mean age of 6.9 years for a prospective longitudinal cohort study. For glucocorticoid analysis, saliva samples were collected (at 7 h, 13 h, 18 h and 21 h) and analyzed with liquid chromatography-tandem mass spectrometry. Parents completed the Strengths and Difficulties Questionnaire. From the parents' perspective, the formerly smaller twins had statistically higher scores regarding hyperactivity (mean 4.63 vs 3.48, p=0.003) and emotional problems (mean 2.67 vs 2.02, p=0.042). Less catch-up growth (Δintra-twin height SDS 4 years of age - Δintra-twin birth length SDS) of the smaller twins was associated with higher scores for hyperactivity (Adj. R²=0.261, p<0.001, β=-1.88, F(1.44)=16.86, n=46, f²=0.35), while smaller birthweight (Adj. R²=0.135, p=0.007, β=-0,87, F(1.44)=8.03, n=46, f²=0.16) and birth length (Adj. R²=0.085, p=0.028, β=-0,78, F(1.44)=5.19, n=46, f²=0.09) were associated with higher scores for peer problems. Greater Δintra-twin for cortisol (7 h: rho=0.337, p=0.029; cumulative: rho=0.458; p=0.024) and cortisone (7 h: rho=0.329, p=0.029; 13 h: rho=0.436, p=0.005) correlated with a greater Δintra-twin for conduct problems. In the discordant group, circa 1 SDS in head circumference persisted from birth (mean SDS: smaller twin −1.18, larger twin −0.08, p<0.001) to present (mean SDS: smaller twin −1.16, larger twin −0.14, p<0.001). Higher cortisol and cortisone concentrations in smaller twins were associated with higher scores for conduct problems. Lower birthweight and absent catch-up growth affected the parents' perspective on the smaller twins' behavior. They saw those children as more hyperactive, with more peer problems and emotional problems. Thus, it seems important to introduce regular check-ups where behavioral difficulties can be assessed, and assistance and advice can be given to the families. Due to the persisting smaller head circumference in the smaller discordant twins, this should be measured regularly. • Correlation between greater intra-twin difference for conduct problems and cortisol • Parents reported more emotional problems and hyperactivity in formerly smaller twin • Absent catch-up growth affected perception of parents on children's behavior • No head-circumference catch-up in smaller twins with greater birthweight difference • Parents and smaller twins differ in perception of health-related quality of life [ABSTRACT FROM AUTHOR]

Computer-assisted technologies have made significant progress in fetoscopic laser surgery, including placental vessel segmentation. However, the intra- and inter-procedure variabilities in the state-of-the-art segmentation methods remain a significant hurdle. To address this, we investigated the use of conditional generative adversarial networks (cGANs) for fetoscopic image segmentation and compared their performance with the benchmark U-Net technique for placental vessel segmentation. Two deep-learning models, U-Net and pix2pix (a popular cGAN model), were trained and evaluated using a publicly available dataset and an internal validation set. The overall results showed that the pix2pix model outperformed the U-Net model, with a Dice score of 0.80 [0.70; 0.86] versus 0.75 [0.0.60; 0.84] (p-value < 0.01) and an Intersection over Union (IoU) score of 0.70 [0.61; 0.77] compared to 0.66 [0.53; 0.75] (p-value < 0.01), respectively. The internal validation dataset further validated the superiority of the pix2pix model, achieving Dice and IoU scores of 0.68 [0.53; 0.79] and 0.59 [0.49; 0.69] (p-value < 0.01), respectively, while the U-Net model obtained scores of 0.53 [0.49; 0.64] and 0.49 [0.17; 0.56], respectively. This study successfully compared U-Net and pix2pix models for placental vessel segmentation in fetoscopic images, demonstrating improved results with the cGAN-based approach. However, the challenge of achieving generalizability still needs to be addressed.

Abstract Background To evaluate the perinatal outcomes in women with selective termination using ultrasound-guided radiofrequency ablation (RFA). Methods Complicated monochorionic (MC) twin pregnancies and multiple pregnancies with an indication for selective termination by ultrasound-guided coagulation of the umbilical cord with RFA under local anesthesia between July 2013 and Jan 2020 were reviewed. We analyzed the indications, gestational age at the time of the procedure, cycles of RFA, duration of the procedure, and perinatal outcome. Results Three hundred and thirteen patients were treated during this period. Seven of whom were lost of follow-up. The remaining 306 cases, including 266 pairs of monochorionic diamniotic (MCDA) twins (86.93%), two pairs of monoamniotic twins (0.65%), 30 dichorionic triamniotic (DCTA) triplets (1%), and three monochorionic triamniotic (MCTA) triplets (0.98%), were analyzed. Indications included twin-to-twin transfusion syndrome (TTTS) (n = 91), selective fetal growth restriction (sFGR) (n = 83), severe discordant structural malformation (n = 78), multifetal pregnancy reduction (MFPR) (n = 78), twin reverse arterial perfusion sequence (TRAPS) (n = 19), and twin anemia-polycythemia sequence (TAPS) (n = 3). Upon comparison of RFA performed before and after 20 weeks, the co-twin loss rate (20.9% vs. 21.5%), the incidence of preterm premature rupture of membranes (PPROM) within 24 h (1.5% vs. 1.2%), and the median gestational age at delivery [35.93 (28–38) weeks vs. 36 (28.54–38.14) weeks] were similar (p > 0.05). Conclusions RFA is a reasonable option when indicated in multiple pregnancies and complicated monochorionic pregnancies. In our experience, the overall survival rate was 78.76% with RFA in selective feticide, and early treatment increases the likelihood of survival for the remaining fetus because the fetal loss rate is similar before and after 20 weeks.

Twin‐to‐twin transfusion syndrome (TTTS) is a severe disorder that often leads to the death of monochorionic twin fetuses, if left untreated. Current prenatal interventions to treat the condition involve the use of rigid fetoscopes for targeted laser coagulation of the vascular anastomoses. These tools are limited in their area of operation, making treatment challenging, especially in cases with anterior placentation. Herein, a robotic platform to perform this task using remote magnetic navigation is proposed. In contrast to rigid tools, the presented custom magnetic fetoscope is highly flexible, dexterous, and has considerable advantages, including safety and precision. A visual servoing algorithm that allows the surgeon to navigate in the uterus with submillimeter precision is introduced. The system has been validated on ex vivo human placentas in a setting that mimics the real intraoperative conditions.

Twin-to-twin transfusion syndrome is a unique disease and a serious complication occurring in 10–15% of monochorionic multiple pregnancies with various placental complications, including hypoxia, anemia, increased oxidative stress, and ischemia-reperfusion injury. Fetoscopic laser photocoagulation, a minimally invasive surgical procedure, seals the placental vascular anastomoses between twins and dramatically improves the survival rates in twin-to-twin transfusion syndrome. However, fetal demise still occurs, suggesting the presence of causes other than placental vascular anastomoses. Placental insufficiency is considered as the main cause of fetal demise in such cases; however, little is known about its underlying molecular mechanisms. Indeed, the further association of the pathogenic mechanisms involved in twin-to-twin transfusion syndrome placenta with several molecules and pathways, such as vascular endothelial growth factor and the renin–angiotensin system, makes it difficult to understand the underlying pathological conditions. Currently, there are no effective strategies focusing on these mechanisms in clinical practice. Certain types of cell death due to oxidative stress might be occurring in the placenta, and elucidation of the molecular mechanism underlying this cell death can help manage and prevent it. This review reports on the molecular mechanisms underlying the development of twin-to-twin transfusion syndrome for effective management and prevention of fetal demise after fetoscopic laser photocoagulation. [ABSTRACT FROM AUTHOR]

Purpose: This study examined the relationships between fetal quantitative Doppler parameters and amniotic fluid N-terminal prohormone brain natriuretic peptide (afNT-proBNP) levels as a biomarker of the increased cardiac load in recipient twins with twin-to-twin transfusion syndrome (TTTS). Methods: This single-center, prospective study included all monochorionic diamniotic (MD) twin pregnancies that were diagnosed with TTTS and underwent fetoscopic laser surgery. Doppler flow was used to measure the pulsatility index (PI) of the umbilical artery (UA), ductus venosus (DV), and middle cerebral artery (MCA) of each recipient and donor twins. The afNT-proBNP levels of recipient twins were examined at the time of surgery. The Spearman or Pearson correlation coefficients were used to assess the relationships between afNT-proBNP levels and Doppler parameters. Results: A total of 150 MD twin pregnancies were included. The afNT-proBNP levels of the recipient twins showed a stronger correlation with the DV-PI (r = 0.637; P < 0.001) of recipient twins than with the UA-PI and MCA-PI of recipient twins. The Doppler parameters of donor twins were scarcely correlated with the afNT-proBNP levels of the recipient twins. Conclusion: A positive correlation between the DV-PI and afNT-proBNP levels of recipient twins with TTTS was observed. The recipient twin with an increased DV-PI is expected to be under a high cardiac load; therefore, DV-PI is a useful parameter for assessing increased NT-proBNP levels consecutively and noninvasively. Clinical Trial Registration: This study was registered with Japanese Clinical Trial Registry "UMIN-CTR" (http://www.umin.ac.jp/ctr/index-j.htm; trial ID numbers UMIN000024486 and 000037702). [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the incidence of antenatally diagnosed brain injury in twin pregnancy complicated by twin-to-twin transfusion syndrome (TTTS) and to quantify the perinatal mortality, morbidity and long-term neurodevelopmental outcome of these fetuses.Methods: MEDLINE, EMBASE, ClinicalTrials.gov and The Cochrane Library databases were searched. Inclusion criteria were studies reporting on brain abnormality diagnosed antenatally in twin pregnancies complicated by TTTS. The primary outcome was the incidence of prenatal brain abnormality. The secondary outcomes were intrauterine demise (IUD), neonatal death, termination of pregnancy (TOP) and long-term morbidity. Outcomes were explored in the population of fetuses with antenatal diagnosis of brain abnormality. Subgroup analysis according to the type of treatment, gestational age, Quintero stage at diagnosis and/or treatment, and cotwin death was planned. Meta-analysis of proportions was used to combine data and pooled proportions and their 95% CI were reported.Results: Thirteen studies including 1573 cases of TTTS and 88 fetuses with an antenatal diagnosis of brain abnormality were included in the systematic review. The meta-analysis included only studies reporting on brain abnormality in twin pregnancy complicated by TTTS cases and treated with laser surgery. Overall, brain injury occurred in 2.2% (52/2410) of fetuses (eight studies). Brain abnormality was reported in 1.03% and 0.82% of recipients and donors, respectively. The most common type of abnormality was ischemic lesions (30.4% (95% CI, 19.1-43.0%)), followed by destructive lesions (23.9% (95% CI, 13.7-35.9%)), ventriculomegaly (19.9% (95% CI, 10.6-31.3%)) and hemorrhagic lesions (15.3% (95% CI, 7.1-25.8%)). Spontaneous IUD occurred in 13.4% (95% CI, 5.1-24.8%) of fetuses, while TOP was chosen by parents in 53.5% (95% CI, 38.9-67.8%) cases. Neonatal death was reported by only three studies, with an incidence of 15.4% (95% CI, 2.8-35.4%). Finally, only two studies reported on composite morbidity, with an overall rate of the outcome of 20.4% (95% CI, 2.5-49.4%) and rates of 29.7% and 20.4% in the recipient and donor fetuses, respectively. Due to the small numbers, only composite morbidity was analyzed and no information on neonatal intensive care unit admission, respiratory distress syndrome or other long-term outcomes, such as neurodevelopmental delay and cerebral palsy, could be retrieved reliably.Conclusions: The overall incidence of antenatally diagnosed fetal brain abnormality in twin pregnancy complicated by TTTS treated with laser surgery is around 2% and is mainly ischemic in nature (30.4%). TOP was chosen by parents in more than half of cases (53.5%). No information could be retrieved on morbidity outcomes, highlighting the urgent need for long-term follow-up studies of these children. © 2022 International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Abstract Background Qualitative research can reflect the actual thoughts and experience of research subjects and can be used to explore the experiences of women presenting with twin-to-twin transfusion syndrome (TTTS) to facilitate the provision of targeted psychological support. Methods A semi-structured interview method was used to assess the pregnancy and parenting experiences of women with TTTS. Colaizzi method was used for data analysis. Results Eighteen women participated in the study. We found that women with TTTS during pregnancy experienced persistent worry about their children’s health from the disease diagnosis to the subsequent parenting processes, even in case of minor changes in their children’s health. The lack of an efficient referral process and health information increased their uncertainty about their children’s health. Conclusion In addition to the children’s health, other difficulties encountered during pregnancy and parenting may aggravate the pressure. Clinicians in the first-visit hospital and foetal medicine centre should improve the referral process and establish a follow-up system to provide women with health information and psychological support.

Aim. To assess the perinatal outcomes of monochorionic diamniotic (MCDA) pregnancy after fetoscopic laser coagulation of anastomoses (FLCA) performed for twin-to-twin transfusion syndrome (TTTS), accompanied by induced or unintentional septostomy, and to identify the factors leading to septostomy. Materials and methods. The retrospective study included 231 cases of FLCA performed in pregnant women with TTTS: in 19 cases septostomy was performed, and in 212 cases intertwin membrane remained intact. Results. The incidence of septostomy during FLCA for TTTS was 8.2%. In 47.3% the rupture of the intertwin membrane occurred during trocar insertion (unintentional septostomy); in 42.1% septostomy was needed to perform laser coagulation of anastomoses located on the placental surface in the donor's amnion (forced septostomy). The placenta was located on the anterior uterine wall in 78.9% in the septostomy group and in 47.6% with an intact intertwin membrane (p=0.01). Anastomoses were located on the donor half of the placenta significantly more often when septostomy was needed to perform selective coagulation of anastomoses located far from the intertwin membrane and obstructed by the body of the donor fetus (42.1%). In 15.8% of patients with septostomy and 2.4% with intact intertwin membrane, umbilical cords of the donor and the recipient fetus were attached closer than 2 cm to each other (p=0.003). In the septostomy group premature rupture of membranes was more frequent (42.1% vs 18.4%, p=0.03) and a delivery time was shorter [26.3 (18.0, 37.0) vs 34.4 (20.3, 40.0) weeks, respectively, p=0.01] than in patients with an intact intertwin membrane. The survival rate after FLCA was lower after septostomy compared to intact intertwin membrane: at least one of the twins survived in 47.4% vs 80.7%, respectively (p=0.002), both fetuses survived in 36.8% vs 75.0%, respectively (p=0.001). Logistic regression analysis showed increased risk of septostomy in patients with the anastomoses located on the donor half of the placenta and when the donor and the recipient umbilical cords are attached close to each other, regardless of the localization of the placenta, gestational age and the stage of TTTS. Conclusion. Lower incidence of unintentional septostomy during FLCA achieved by using modern equipment and surgical techniques will lead to better perinatal outcomes in patients with MCDA twins with TTTS.

ObjectiveThis study explored the effect of fetoscopic laser surgery on the placental structure and birth-weight discordance of twin-to-twin transfusion syndrome (TTTS).MethodsA retrospective cohort study was conducted in TTTS patients who were admitted to the Peking University Third Hospital between April 2014 and April 2020. The patients were divided into two groups: laser group and control group. Placentas with twin survival were injected, and pregnancy outcomes and placental characteristics of the two groups were compared. The correlation between the birth-weight discordance and placental characteristics in each group was analyzed.ResultsThe gestational age at first diagnosis in the laser group was significantly smaller than that in the control group (21.6 ± 2.8 weeks vs. 27.7 ± 3.0 weeks, p < 0.001). The proportion of patients with TTTS stage-I in the laser group was significantly lower than the control group (9.4 vs. 64.0%, p < 0.001). The gestational age at delivery in the laser group was significantly larger than that in the control group (33.6 ± 2.1 weeks vs. 31.4 ± 2.5 weeks, p = 0.001). In the laser group, the birth-weight discordance ratio was positively correlated with the placental territory discordance ratio (Spearman coefficient = 0.556; p = 0.001).ConclusionThe birth-weight discordance is positively correlated with placental territory discordance in TTTS patients after FLS.