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Objectives: To develop a deep learning (DL)-model using convolutional neural networks (CNN) to automatically identify the fetal head position at transperineal ultrasound in the second stage of labor., Material and Methods: Prospective, multicenter study including singleton, term, cephalic pregnancies in the second stage of labor. We assessed the fetal head position using transabdominal ultrasound and subsequently, obtained an image of the fetal head on the axial plane using transperineal ultrasound and labeled it according to the transabdominal ultrasound findings. The ultrasound images were randomly allocated into the three datasets containing a similar proportion of images of each subtype of fetal head position (occiput anterior, posterior, right and left transverse): the training dataset included 70 %, the validation dataset 15 %, and the testing dataset 15 % of the acquired images. The pre-trained ResNet18 model was employed as a foundational framework for feature extraction and classification. CNN 1 was trained to differentiate between occiput anterior (OA) and non-OA positions, CNN 2 classified fetal head malpositions into occiput posterior (OP) or occiput transverse (OT) position, and CNN 3 classified the remaining images as right or left OT. The DL-model was constructed using three convolutional neural networks (CNN) working simultaneously for the classification of fetal head positions. The performance of the algorithm was evaluated in terms of accuracy, sensitivity, specificity, F1-score and Cohen's kappa., Results: Between February 2018 and May 2023, 2154 transperineal images were included from eligible participants across 16 collaborating centers. The overall performance of the model for the classification of the fetal head position in the axial plane at transperineal ultrasound was excellent, with an of 94.5 % (95 % CI 92.0--97.0), a sensitivity of 95.6 % (95 % CI 96.8-100.0), a specificity of 91.2 % (95 % CI 87.3-95.1), a F1-score of 0.92 and a Cohen's kappa of 0.90. The best performance was achieved by the CNN 1 - OA position vs fetal head malpositions - with an accuracy of 98.3 % (95 % CI 96.9-99.7), followed by CNN 2 - OP vs OT positions - with an accuracy of 93.9 % (95 % CI 89.6-98.2), and finally, CNN 3 - right vs left OT position - with an accuracy of 91.3 % (95 % CI 83.5-99.1)., Conclusions: We have developed a DL-model capable of assessing fetal head position using transperineal ultrasound during the second stage of labor with an excellent overall accuracy. Future studies should validate our DL model using larger datasets and real-time patients before introducing it into routine clinical practice., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: The evidence-based management of human labor includes the antepartum identification of patients at risk for intrapartum hypoxia. However, available evidence has shown that most of the hypoxic-related complications occur among pregnancies classified at low-risk for intrapartum hypoxia, thus suggesting that the current strategy to identify the pregnancies at risk for intrapartum fetal hypoxia has limited accuracy., Objective: To evaluate the role of the combined assessment of the cerebroplacental ratio (CPR) and uterine arteries (UtA) Doppler in the prediction of obstetric intervention (OI) for suspected intrapartum fetal compromise (IFC) within a cohort of low-risk singleton term pregnancies in early labor., Methods: Prospective multicentre observational study conducted across four tertiary Maternity Units between January 2016 and September 2019. Low-risk term pregnancies with spontaneous onset of labor were included. A two-step multivariable model was developed to assess the risk of OI for suspected IFC. The baseline model included antenatal and intrapartum characteristics, while the combined model included antenatal and intrapartum characteristics plus Doppler anomalies such as CPR MoM < 10th percentile and mean UtA Doppler PI MoM ≥ 95th percentile. Predictive performance was determined by receiver-operating characteristics curve analysis., Results: 804 women were included. At logistic regression analysis, CPR MoM < 10th percentile (aOR 1.269, 95 % CI 1.188-1.356, P < 0.001), mean UtA PI MoM ≥ 95th percentile (aOR 1.012, 95 % CI 1.001-1.022, P = 0.04) were independently associated with OI for suspected IFC. At ROC curve analysis, the combined model including antenatal characteristics plus abnormal CPR and mean UtA PI yielded an AUC of 0.78, 95 %CI(0.71-0.85), p < 0.001, which was significantly higher than the baseline model (AUC 0.61, 95 %CI(0.54-0.69), p = 0.007) (p < 0.001). The combined model was associated with a 0.78 (95 % CI 0.67-0.89) sensitivity, 0.68 (95 % CI 0.65-0.72) specificity, 0.15 (95 % CI 0.11-0.19) PPV, and 0.98 (0.96-0.99) NPV, 2.48 (95 % CI 2.07-2.97) LR + and 0.32 (95 % CI 0.19-0.53) LR- for OI due to suspected IFC., Conclusions: A predictive model including antenatal and intrapartum characteristics combined with abnormal CPR and mean UtA PI has a good capacity to rule out and a moderate capacity to rule in OI due to IFC, albeit with poor predictive value., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objective: to investigate the correlation between the intrapartum CardioTocoGraphic (CTG) findings "suggestive of fetal inflammation" ("SOFI") and the interleukin (IL)-6 level in the umbilical arterial blood., Study Design: prospective cohort study conducted at a tertiary maternity unit and including 447 neonates born at term., Methods: IL-6 levels were systematically measured at birth from a sample of blood taken from the umbilical artery. The intrapartum CTG traces were retrospectively reviewed by two experts who were blinded to the postnatal umbilical arterial IL-6 values as well as to the neonatal outcomes. The CTG traces were classified into "suggestive of fetal inflammation (SOFI)" and "no evidence of fetal inflammation (NEFI) according to the principles of physiologic interpretation the CTG traces. The CTG was classified as "SOFI" if there was a persistent fetal heart rate (FHR) increase > 10 % compared with the observed baseline FHR observed at the admission or at the onset of labor without any preceding repetitive decelerations. The occurrence of Composite Adverse Outcome (CAO) was defined as Neonatal Intensive Care Unit (NICU) or Special Care Baby Unit (SCBU) admission due to one or more of the following: metabolic acidaemia, Apgar score at 5 min ≤ 7, need of neonatal resuscitation, respiratory distress, tachypnoea/polypnea, jaundice requiring phototherapy, hypotension, body temperature instability, poor perinatal adaptation, suspected or confirmed early neonatal sepsis., Main Outcome Measures: To compare the umbilical IL-6 values between the cases with intrapartum CTG traces classified as "SOFI" and those classified as "NEFI"; to assess the correlation of umbilical IL-6 values with the neonatal outcome., Results: 43 (9.6 %) CTG traces were categorized as "SOFI"; IL-6 levels were significantly higher in this group compared with the "NEFI" group (82.0[43.4-325.0] pg/ml vs. 14.5[6.8-32.6] pg/mL; p <.001). The mean FHR baseline assessed 1 h before delivery and the total labor length showed an independent and direct association with the IL-6 levels in the umbilical arterial blood (p <.001 and p = 0.005, respectively). CAO occurred in 33(7.4 %) cases; IL-6 yielded a good prediction of the occurrence of the CAO with an AUC of 0.72 (95 % CI 0.61-0.81)., Conclusion: Intrapartum CTG findings classified as "SOFI" are associated with higher levels of IL-6 in the umbilical arterial blood., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objectives: To evaluate the role of the cervical sliding sign (CSS) in the prediction of the outcome of induction of labor (IOL)., Study Design: Two-center prospective observational cohort study involving a non-consecutive series of uncomplicated singleton term pregnancies, planned for IOL, with a fetus in cephalic presentation and unfavorable cervix as defined by a Bishop score ≤ 6. The Bishop score was evaluated by transvaginal digital examination and the cervical length and CSS by transvaginal ultrasound. The presence of CSS was defined as the sliding of the anterior cervical lip on the posterior one under gentle pressure of the transvaginal probe. The primary outcome of the study was successful vaginal delivery within 24 h. The secondary outcome was the induction-to-active-labor time. The interobserver agreement for the CSS was also evaluated., Results: Over a period of 12 months, 179 women were included. The CSS was found in 86 (48.0 %) patients and was associated with an increased likelihood of vaginal delivery within 24 h (60/86 or 69.8 % vs 27/93 or 29.0 %, P < 0.001) and a shorter induction-to-active-labor time (954 ± 618 min vs 1416 ± 660 min, P < 0.001). Multivariable regression analysis showed that the CSS was an independent predictor of vaginal delivery within 24 h (aOR 5.37, 95 % CI 2.26-12.75) and shorter induction-to-active-labor time interval (HR 1.81, 95 % CI 1.19-2.74). The interobserver variability based on intraclass correlation coefficient for the CSS was excellent (ICC = 0.90)., Conclusion: In women undergoing IOL with an unfavorable cervix, the CSS is associated with a higher frequency of vaginal delivery within 24 h and a shorter induction-to-active-labor time., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Objective: The aim of this study was to report the rate of additional anomalies detected exclusively at prenatal magnetic resonance imaging (MRI) in fetuses with isolated severe ventriculomegaly undergoing neurosonography., Method: Multicenter, retrospective, cohort study involving 20 referral fetal medicine centers in Italy, United Kingdom, Spain and Denmark. Inclusion criteria were fetuses affected by isolated severe ventriculomegaly (≥15 mm), defined as ventriculomegaly with normal karyotype and no other additional central nervous system (CNS) and extra-CNS anomalies on ultrasound. In all cases, a multiplanar assessment of fetal brain as suggested by ISUOG guidelines on fetal neurosonography had been performed. The primary outcome was the rate of additional CNS anomalies detected exclusively at fetal MRI within two weeks from neurosonography. Subgroup analyses according to gestational age at MRI (

Objectives: To assess whether the additional training with transabdominal ultrasound may improve the accuracy of the transvaginal digital examination in the assessment of the fetal head position during the active stage of labor., Methods: Prospective observational study involving 2 residents in their 1 st year of training in Obstetrics with no prior experience in neither transvaginal digital examination nor ultrasound. Women with term, cephalic presenting fetus and active labor with cervical dilation ≥ 8 cm and ruptured membranes were included. In the preliminary phase of the study, the resident A ("blinded") was assigned to assess the fetal head position by transvaginal digital examination, while the resident B ("unmasked") performed transvaginal digital examination following transabdominal ultrasound, which was considered to be the gold standard to determine the fetal head position. After 50 examinations independently performed by each resident in the training phase, a post-training phase of the study was carried out to compare the accuracy of each resident in the diagnosis of fetal head position by digital assessment. The occiput position was eventually confirmed by ultrasound performed by the main investigator., Results: Over a 6 months period, 90 post-training vaginal examinations were performed by each resident. The number of incorrect diagnoses of head position was higher for the "blinded" resident compared with the "unmasked" resident subjected to the ultrasound training (28/90 or 31.1 % vs 15/90 or 16.7 % p = 0.02). For both residents a wrong diagnosis was more likely with non-OA vs OA fetuses but this difference was statistically significant for the "blinded" Resident (10/20 or 50 % vs 18/70 or 25.7 % p = 0.039) but not for the "unmasked" Resident (5/18 or 27.9 % vs 10/72 or 13.9 % p = 0.16)., Conclusion: The addition of transabdominal ultrasound as a training tool in the determination of the fetal head position during labor seems to improve the accuracy of the transvaginal digital examination in unexperienced residents., Competing Interests: Declaration of Competing Interest The authors report no declarations of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objectives: The choice of growth charts impacts on screening, diagnosis and clinical management of fetal growth abnormalities. The objectives of the study were to evaluate: 1) the clinical practice at a national level among tertiary referral centers in the use of fetal biometric growth charts; and 2) the impact on fetal growth screening of existing national and international growth charts., Study Design: A questionnaire was sent to 14 Italian tertiary referral centers to explore biometric reference growth charts used in clinical practice. National and international (Intergrowth-21st and World Health Organization) fetal growth charts were tested on a large national cohort of low risk women with singleton uneventful pregnancy derived from a retrospective cross-sectional multicenter study (21 centers). The percentage of fetuses with biometric measurements below and above the 10th and 90th percentile for each biometric parameter and gestational week were calculated for each growth chart. The percentile curves of the study population were calculated by non-linear quantile regressions., Results: Twelve Italian centers (86 %) answered to the questionnaire showing a wide discrepancy in the use of growth charts for fetal biometry. The cohort included 7347 pregnant women. By applying Intergrowth-21st growth charts the percentage of fetuses with head circumference, abdominal circumference and femur length below the 10th centile was 3.9 %, 3.6 % and 2.3 %, and above the 90th centile 29.9 %, 32.5 % and 46 %, respectively. The percentages for the World Health Organization growth charts for head and abdominal circumferences and femur length were: below the 10th centile 6.3 %, 7.2 % and 5.3 %, and above 90th centile 22.8 %, 21.3 % and 31.9 %, respectively., Conclusions: The wide discrepancy in clinical use of fetal growth charts in Italian centers warrants the adoption of an uniform set of charts. Our data suggest that immediate application into clinical practice of international growth charts might result into an under-diagnosis of small for gestational age fetuses and, especially, in an over-diagnosis of large for gestational age fetuses with major consequences for clinical practice. On these grounds, there is an urgent need for a nationwide study for the prospective evaluation of international growth charts and, if needed, the construction and adoption of methodologically robust national growth charts., Competing Interests: Declaration of Competing Interest The authors state no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Introduction: The antenatal diagnosis of placenta accreta spectrum (PAS) is in large part subjective and based on expert interpretation. The aim of this study was to externally evaluate a recently developed staging system based on specific and defined prenatal ultrasound (US) features in a cohort of women at risk of PAS undergoing specialist prenatal US, in particular relating to surgical morbidity at delivery., Materials and Methods: Database study of cases with confirmed placenta previa. In all, the placenta was evaluated in a systematic fashion. PAS was subclassified in PAS0-PAS3 according to the loss of clear zone, placental lacunae, bladder wall interruption, uterovesical hypervascularity and increased vascularity in the parametrial region., Results: 43 cases were included, of whom 33 had major placenta previa. 31 cases were categorized as PAS0; 3, 4 and 5 cases as PAS1, PAS2 and PAS3, respectively. All women underwent caesarean section and hysterectomy was required in 10. The comparison of the perinatal outcomes among the PAS categories yielded greater operative time (50 (35-129) minutes for PAS0 vs 70 (48-120) for PAS1 vs 95 (60-150) for PAS2 vs 100 (87-180) for PAS3, p < 0.001) and estimated blood loss (800 (500-2500) mls for PAS0 vs 3500 (800-7500) for PAS1 vs 2850 (500-7500) for PAS2 vs 6000 (2500-11000) for PAS3, p < 0.001) for the highest PAS categories, which were also associated with a higher rate of hysterectomy (p < 0.001), blood transfusion (p = 0.002) and admission to ITU or HDU (p < 0.001) and longer postoperative admission of 3 (1-9) days for PAS0 vs 3 (2-12) for PAS1 vs 4.5 (3-6) for PAS2 vs 5 (3-22) for PAS3, p = 0.02., Conclusion: Perioperative complications are closely associated with PAS stage. This information is useful for counselling women and may be important in allocating staff and infrastructure resources at the time of delivery., Competing Interests: Declaration of Competing Interest The Authors state no financial disclosures nor conflict of interest related to the content of this work., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Introduction: Fetal overgrowth is an acknowledged risk factor for abnormal labor course and maternal and perinatal complications. The objective of this study was to evaluate whether the use of antenatal ultrasound-based customized fetal growth charts in fetuses at risk for large-for-gestational age (LGA) allows a better identification of cases undergoing caesarean section due to intrapartum dystocia., Material and Methods: An observational study involving four Italian tertiary centers was carried out. Women referred to a dedicated antenatal clinic between 35 and 38 weeks due to an increased risk of having an LGA fetus at birth were prospectively selected for the study purpose. The fetal measurements obtained and used for the estimation of the fetal size were biparietal diameter, head circumference, abdominal circumference and femur length, were prospectively collected. LGA fetuses were defined by estimated fetal weight (EFW) >95th centile either using the standard charts implemented by the World Health Organization (WHO) or the customized fetal growth charts previously published by our group. Patients scheduled for elective caesarean section (CS) or for elective induction for suspected fetal macrosomia or submitted to CS or vacuum extraction (VE) purely due to suspected intrapartum distress were excluded. The incidence of CS due to labor dystocia was compared between fetuses with EFW >95th centile according WHO or customized antenatal growth charts., Results: Overall, 814 women were eligible, however 562 were considered for the data analysis following the evaluation of the exclusion criteria. Vaginal delivery occurred in 466 (82.9 %) women (435 (77.4 %) spontaneous vaginal delivery and 31 (5.5 %) VE) while 96 had CS. The EFW was >95th centile in 194 (34.5 %) fetuses according to WHO growth charts and in 190 (33.8 %) by customized growth charts, respectively. CS due to dystocia occurred in 43 (22.2 %) women with LGA fetuses defined by WHO curves and in 39 (20.5 %) women with LGA defined by customized growth charts (p 0.70). WHO curves showed 57 % sensitivity, 72 % specificity, 24 % PPV and 91 % NPV, while customized curves showed 52 % sensitivity, 73 % specificity, 23 % PPV and 91 % NPV for CS due to labor dystocia., Conclusions: The use of antenatal ultrasound-based customized growth charts does not allow a better identification of fetuses at risk of CS due to intrapartum dystocia., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: The estimation of the fetal weight by three-dimensional (3D) ultrasound (US) with fractional thigh volume (TVol) has been suggested to be more accurate than two-dimensional (2D) US particularly within the context of fetuses at risk of macrosomia. The objective of this study was to compare the accuracy of 2D US and 3D US with two different methods of projection for the identification of fetal macrosomia at term., Study Design: Prospective study which included women at risk for fetal macrosomia referred for fetal biometry between 34 +0 -36 +6 weeks. The estimated fetal weight (EFW) was computed using 2D US and the Hadlock Model IV or through 3D US and the Model VI by Lee et al. The projection of the EFW at the time of delivery was performed by using Yudkin's chart percentiles and the gestation-adjusted projection (GAP) method., Results: Overall, 230 patients were included. Paired comparison between 2D-US-EFW and 3D-US-EFW with either method of projection of the EFW at birth suggested different properties of the techniques, being 2D-US-EFW associated with higher sensitivity and 3D-US-EFW with higher specificity, PPV and LR + . At ROC curve no difference was found in the prediction of birthweight ≥90th centile using 2D-US-EFW or 3D-US-EFW (AUC 0.831, 95%CI 0.768-0.894 versus AUC 0.860, 95%CI 0.799-0.920, respectively, p 0.37) nor in the prediction of birthweight >95th centile with 2D-US-EFW compared to 3D-US-EFW (0.803, 95%CI 0.731-0.874 versus 0.866, 95%CI 0.805-0.926, respectively, p 0.07). Similarly, a non-significant difference in the accuracy of the prediction of birthweight >4000 g (AUC 0.788, 95%CI 0.716-0.859 for 2D-US-EFW vs AUC 0.802, 95%CI 0.723-0.880 for 3D-US-EFW, p 0.72) and >4500 g (0.828, 95%CI 0.720-0.936 for 2D-US-EFW vs 0.858, 95%CI 0.759-0.956 for 3D-US-EFW, p 0.71) with the GAP method could be demonstrated., Conclusions: Within a population at risk of fetal macrosomia the performance of 3D-US-EFW is similar to that of 2D-US-EFW in the prediction of macrosomia at term regardless of the method used for the projection of the EFW, however different properties were noted between the two techniques. Such finding suggests a potential complementary role of the techniques which warrants evaluation in future research., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The recently published ARRIVE trial demonstrated that "policies aimed at the avoidance of elective labour induction among low-risk nulliparous women at 39 weeks of gestation are unlikely to reduce the rate of caesarean delivery on a population level". In this commentary we discuss some controversial aspects of the study that in our opinion may undermine its validity at wide population level., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Introduction: Umbilical artery blood analysis is assumed to give a picture of the acid-base balance of the infant at birth and is considered the gold standard to diagnose neonatal acidemia at birth. The evaluation of umbilical vein pH has been suggested as an adjunct in order to optimize the understanding of the pathophysiology of the hypoxic events in labor. The objective of this study was to assess the correlation between the Delta pH (vein-to-artery) on the umbilical cord and the intrapartum cardiotocography (CTG) patterns in a selected cohort of acidemic neonates., Methods: Retrospective analysis of all CTG traces from non-anomalous term neonates consecutively born with acidemia (pH < 7.05 on the arterial cord) at four European tertiary Maternity Units. Intrapartum CTG traces were collected and their characteristics were reviewed in consensus by three senior Obstetricians. Each case was assigned to one of these four types of intrapartum hypoxia according to the CTG features: acute hypoxia, subacute hypoxia, slowly evolving hypoxia, and chronic hypoxia. The relationship between the different categories of intrapartum hypoxia and the Delta pH on the umbilical cord were evaluated., Results: Overall, 83 acidemic neonates were included. Acute hypoxia, subacute hypoxia, slowly evolving hypoxia, and chronic hypoxia accounted for 19 (22.9%), 24 (28.9%), 24 (28.9%) and 16 (19.3%) cases, respectively. No difference of the Delta pH (p 0.61) was noted across the CTG subclasses, while significantly lower birthweight among cases with chronic hypoxia was found (p 0.03). The mean Delta pH did not vary at comparison between the cases with rapid onset hypoxia (acute + subacute hypoxia) and those with long lasting hypoxia (chronic + slowly evolving) (p 0.59)., Conclusions: Within a selected cohort of acidemic neonates, our data do not demonstrate an association between the different CTG patterns of intrapartum hypoxia and the artery-to-vein Delta pH on the umbilical cord., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objective: To assess the association between fetal size and the incidence of reduced short-term variability (STV) following bethametasone administration for fetal lung maturity., Study Design: This was a retrospective, multicenter, cohort study conducted in two Tertiary University Units. Only uncomplicated singleton pregnancies admitted for threatened preterm labor between 26 and 34 weeks and submitted to betamethasone for fetal lung maturity were included. Delivery occurring within 72h from betamethasone administration represented criteria for exclusion. Computerized cardiotocography was carried out on a daily basis. Cases were identified by persistently reduced STV, defined as <5th percentile for gestational age and lasting for at least 72h after the first dose of betamethasone. The primary outcome was estimated fetal weight (EFW) at ultrasound in fetuses with normal and in those with persistently reduced STV. Pregnancy outcomes were also evaluated., Results: Persistently reduced STV occurred in 33/405 of the included patients (8.1%). Compared to women with normal STV, those with persistently reduced STV had significantly lower EFW (1472±435 vs 1812±532g, p 0.04), lower birthweight (2353±635 vs 2857±796g, p<0.01) and earlier gestational age at delivery (35.1±4.2 vs 37.3±2.4weeks, p<0.01), whereas all the other variables including gestational age on admission were comparable., Conclusions: Reduced STV following maternal betamethasone administration among appropriately grown fetuses seems to correlate with lower fetal size. Furthermore, fetuses with such abnormal response to steroids seem to carry a higher risk of perinatal complications, including lower birthweight and earlier gestational age at delivery., (Copyright © 2017. Published by Elsevier B.V.)

Introduction: Vacuum extractor has been increasingly used over the last decades and is acknowledged as a risk factor for shoulder dystocia (SD). In this meta-analysis we assess the actual risk of SD following a vacuum delivery compared to spontaneous vaginal delivery (SVD) and forceps., Materials and Methods: Systematic literature search (English literature only) on MEDLINE, EMBASE, ScienceDirect, the Cochrane library and ClinicalTrials.gov conducted up to May 2015. Key search terms included: Operative/Vacuum/Forceps delivery [Mesh] and shoulder dystocia and subheadings. 2 stage-process study selection. We included only studies where data concerning the occurrence of SD following operative vaginal delivery were reported as adjusted odds ratio (AOR) and no significant difference in confounding factors for SD was recorded. Included trials clustered according to the delivery mode (1) vacuum vs. SVD, (2) forceps vs. vacuum. Methodological quality of each study evaluated with the Newcastle-Ottawa System (NOS)., Results: 87 potentially relevant papers. After applying inclusion and exclusion criteria only 7 were selected for the meta-analysis. Vacuum delivery appeared associated with a higher risk of SD than SVD in both fixed and random model (OR 2.87 and 2.98 respectively). No difference in the rate of SD was found between vacuum and forceps (p>0.05)., Conclusion: Vacuum extractor carries an increased risk of SD compared with spontaneous vaginal delivery whereas the occurrence of SD does not seem to vary following vacuum or forceps., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)