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Abstract: Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2011 there were twelve themed workshops, three of which are summarized in this report. These workshops related to vascular systems and circulation in the mother, placenta and fetus, and were divided in to 1) angiogenic signaling and regulation of fetal endothelial function; 2) placental and fetal circulation and growth; 3) spiral artery remodeling. [Copyright &y& Elsevier]

A letter to the editor is presented in response to the article about a direct method for ultrasound prediction of day of delivery.

An excerpt from the comments about the abnormal ductus venosus by T. Kiserud is presented.

Objective: To study fertility among women treated by means of ultrasound-guided drainage and antibiotics for tubo-ovarian abscess (TOA). Design: Retrospective cohort study. Setting: A tertiary referral center. Patient(s): One hundred women of reproductive age treated for TOA between June 1986 and July 2003. Intervention(s): Transvaginal ultrasound-guided drainage of TOA was performed in all patients. The procedure was repeated if a substantial amount of pus was seen using ultrasonography 2-5 days after the initial aspiration, and repeated later if necessary. Main Outcome Measure(s): Frequency of naturally conceived pregnancies. Result(s): Twenty of 38 (52.6%; 95% CI 36.5-68.9%) women who intended to have a child achieved pregnancy naturally and became mothers. In addition, 7 (50%) of 14 women who were not on birth control on a regular basis became pregnant. No ectopic pregnancies were registered. Conclusion(s): Ultrasound-guided drainage of TOA in combination with antibiotics seems to preserve fertility in approximately half of the patients. [ABSTRACT FROM AUTHOR]

Objectives Normal anatomical and physiological development of the maternal anal canal during and after pregnancy has been documented scarcely. We aimed to study the position and volume of the anal canal, during and after pregnancy, in women without previous delivery. Methods This was a longitudinal study in which transvaginal three-dimensional ultrasound was used to measure anatomical structures in the anal canal during rest and squeeze in 23 nulliparous women. The total anal canal volume (ACV), anorectal curvature (ARC), anovaginal angle (AVA) and anal canal length were determined at 18, 28 and 36 weeks of pregnancy and at 3 months postpartum. Results Total ACV at rest increased from a mean of 10.17 cm3 at 18 weeks to 12.37 cm3 and 12.21 cm3 at 28 and 36 weeks, respectively ( P = 0.001 and P = 0.010 vs. first measurement). For anal canal length, the corresponding mean measurements were 3.91 cm, 4.07 cm ( P = 0.13) and 4.21 cm ( P = 0.017). Postpartum, the mean total ACV was 10.86 cm3 and length was 3.90 cm ( P = 0.10 and P = 0.70 vs. first measurement). No significant changes were observed in ARC and AVA during or after pregnancy. Compared to at-rest status, the anal length significantly increased on voluntary squeeze ( P = 0.007, 0.007, 0.022 and 0.004 at the four time points), while no differences in total ACV were observed. In mid-pregnancy AVA significantly increased during squeeze ( P = 0.006 and 0.002 at weeks 18 and 28, respectively). Conclusion Anal canal length and total ACV increase during pregnancy in women without previous delivery. Voluntary squeezing elongates the anal canal and increases the angle formed with respect to the direction of the vagina. During postpartum involution, the characteristics of the anal canal revert to those observed at 18 weeks of pregnancy. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Objective To determine the venous and arterial hemodynamics underlying macrosomic fetal growth. Methods Fifty-eight healthy women who previously had given birth to a large neonate were included in a prospective longitudinal study. Of these, 29 gave birth to neonates with birth weight ≥ 90 th percentile and were included in the statistical analysis. Umbilical vein blood flow and Doppler measurements of the ductus venosus, left portal vein and the hepatic, splenic, superior mesenteric, cerebral and umbilical arteries were repeated at 3-5 examinations during the second half of pregnancy and compared with the corresponding reference values. Ultrasound biometry was used to estimate fetal weight. Results Umbilical blood flow increased faster in macrosomic fetuses, showed less blunting near term and was also significantly higher when normalized for estimated fetal weight ( P < 0.0001). The portocaval perfusion pressure of the liver (expressed by the ductus venosus systolic blood velocity) and the left portal vein blood velocity (expressing umbilical venous distribution to the right liver lobe) were significantly higher. Systolic velocity was higher in the splenic, superior mesenteric, cerebral and umbilical arteries, while the pulsatility index was unaltered in the cerebral, hepatic, splenic and mesenteric arteries, but lower in the umbilical artery. Conclusions There is an augmented umbilical flow in macrosomic fetuses particularly near term, also when normalized for estimated fetal weight, providing increased liver perfusion, including the right liver lobe. Signs of increased vascular cross section and flow are also seen on the arterial side but not expressed in the pulsatility index of organs with prominent auto-regulation (i.e. brain, liver, spleen and gut). Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Objectives To explore the possibility of using transvaginal 3D ultrasound as a method of assessing the compartments of the anal canal during rest, to determine the effect of squeeze, and to compare these findings with those obtained using the endoanal technique in the same women. Methods Transvaginal 3D ultrasound was used in a cross-sectional study measuring the anal mucosa and sphincters during rest and squeeze in 20 nulligravida women, comparing the results with those of endoanal measurements. Measurements were also performed of the anal mucosa, anorectal curvature (ARC), and anovaginal angle (AVA) and distance (AVD). Results Volume measurements of the anal mucosa were only possible using transvaginal ultrasound. The mean volume of the anal canal using the transvaginal technique was 7.93 (SD 2.26) and 7.34 (1.54) cm3 during rest and squeeze, respectively (P = 0.082). The ARC became more acute (3.46 vs. 4.12°/mm, P = 0.031) during squeeze and AVA increased (31.7° vs. 35.8°, P = 0.010). The volume of the anal mucosa (3.12 cm3) did not change (P = 0.193), but was distorted during squeeze at the level of the puborectalis sling (P < 0.001 for upper crosssection and diameter). The anal canal was 1 cm longer (P < 0.001), the IAS volume larger (2.97 and 2.08 cm3, P = 0.003), and the EAS volume smaller (1.85 and 3.96 cm3, P < 0.001) using the 3D transvaginal technique compared with the endoanal measurements at rest, with similar differences observed on squeeze. Conclusion In contrast to the endoanal method, transvaginal 3D ultrasound provides a complete assessment of the anal canal, including themucosa. This method seems suitable for functional studies such as in the present one, which shows that voluntary squeeze increases the angulation of the anal canal and distorts the bowel crosssection at the level of the puborectal muscle. [ABSTRACT FROM AUTHOR]

To evaluate the effect of elective caesarean section (CS) before term and early enteral nutrition on length of parenteral nutrition and hospital stay in infants with gastroschisis. Retrospective review of all infants with gastroschisis treated in a regional level III hospital from 1993 to 2008. During 1993-97, there was no established standard for management of pregnancy or delivery while a protocol on close foetal monitoring and early elective CS was adhered to for 1998-2008. Introduction of human milk on the first day after complete closure of the abdominal wall and rapid increase was the policy during the whole period. With early elective CS, no foetal deaths occurred after 28- week gestational age (GA). Ten infants were born during the first period and 20 during the second period at a median GA (range) of 36.5 (34-40) and 35 (34-37) weeks (p = 0.013). Seven and 20, respectively, were born by CS. Median (range) days before full enteral feeds and hospital stay were 11.5 (7-39) and 13.0 (7-46) (p = 0.85), and 17.5 (12-36) and 22.5 (13-195) (p = 0.67), respectively. One child died of volvulus after discharge. Close surveillance of pregnancy, elective preterm caesarean section, early surgery and active approach to primary closure and early enteral feeds appears to be a safe and effective line of management in gastroschisis. [ABSTRACT FROM AUTHOR]

The article focuses on a study in obstetrics that investigates the blood velocity pattern of the left portal vein and its development during the second half of pregnancy and tests the hypothesis that reversal of flow in the left portal vein may be a normal phenomenon. It notes that the left portal vein represents a watershed area in fetal circulation. It points out that the occurrence of pulsations in the left portal branch is a normal phenomenon, and so is reversal flow.

Objectives: To establish reference ranges suitable for serial assessments of the fetal middle cerebral (MCA) and umbilical (UA) artery blood flow velocities, pulsatility index (PI) and cerebroplacental pulsatility ratio and to provide terms for calculating conditional reference intervals suitable for individual serial measurements. Methods: This was a longitudinal study of 161 singleton pregnancies. Using Doppler ultrasound, MCA and UA blood velocities and PI were determined three to five times at 3-5-week intervals over a gestational age range of 19-41 weeks. Polynomial regression lines for the 95th, 50th and 5th percentiles were calculated for the peak systolic velocity (PSV), time-averaged maximum velocity (TAMXV), PI and cerebroplacental ratio. Terms for calculating conditional reference intervals were established. Results: Based on 566 observations our new longitudinal reference ranges for fetal middle cerebral PSV, TAMXV and PI provided terms for calculating conditional reference intervals (i.e. predicting expected 95% confidence limits based on a previous measurement), and correspondingly for the cerebroplacental ratio (n = 550). The reference ranges were at some variance with those of previous cross-sectional studies. The narrow 95% confidence limits for the 5(th) and 95(th) percentiles ensured reliable ranges. Conclusions: We have established longitudinal reference ranges appropriate for the serial assessment of MCA blood velocities and PI and cerebroplacental ratio. Particularly the terms for calculating conditional ranges based on a previous observation make this system more appropriate for longitudinal monitoring than are cross-sectional data. [ABSTRACT FROM AUTHOR]

Objectives: The umbilical vein is the major source of blood for the fetal liver, but portal blood, which has not been measured directly in human fetuses, probably constitutes a physiologically important contribution. We aimed to establish a method for measuring blood flow in the fetal portal vein and to produce longitudinal reference ranges for diameter, blood flow velocities and volume blood flow during the second half of pregnancy. Methods: After a pilot project to develop the measuring technique, 160 low-risk pregnant women were recruited to a longitudinal study that included ultrasound examinations at 4-5-week intervals starting at 20-22 weeks of gestation. The inner diameter (D) of the vessel was measured with a perpendicular insonation angle, and the time-averaged maximum blood velocity (TAMXV) and weighted mean velocity (VWMEAN) were recorded with an insonation directed along the long axis of the vessel. Portal flow was calculated as: Q = pi(D/2)(2) x h x TAMXV (where h is a velocity profile parameter and equals 0.5). Portal flow was normalized for estimated fetal weight based on birth-weight percentiles. Results: The portal vein could be visualized and measured in 558/593 (94%) cases. Blood flow was pulsatile. D and TAMXV doubled during the second half of pregnancy (21-39 weeks), from 1.5 to 3.4 mm and from 8.4 to 14.9 cm/s, respectively. Correspondingly, the portal flow increased from 5 to 41 mL/min, and from 10 to 13 mL/min/kg when normalized for fetal weight. Similar results were achieved for VWMEAN. Conclusion: Portal flow can be measured with a standardized technique. It increases during the second half of pregnancy, even when normalized for fetal weight, suggesting that it has increasing importance in the fetal liver circulation. [ABSTRACT FROM AUTHOR]

In utero somatic gene therapy in the later stages of pregnancy may allow targeting of organ systems which are difficult to reach later in life and to prevent the development of tissue damage otherwise caused by the early onset of inherited diseases. We report here on the percutaneous delivery of two adenoviral vectors, containing the β-galactosidase reporter gene and the human Factor IX gene respectively, to the fetal liver and circulation by ultrasound-guided umbilical vein puncture similar to procedures used in human pregnancy. Vector spread, as detected by PCR analysis for the β-galactosidase encoding vector, was found in almost all fetal and neonatal organs and in the maternal liver. Expression of the β-galactosidase transgene was detected in many fetal tissues by RT-PCR. High β-galactosidase production was shown by immuno-histochemistry predominantly in the liver, where about 30% of the hepatocytes stained positive, and in the adrenal cortex. Production of factor IX was determined by ELISA in the plasma of treated fetuses and newborn lambs and reached at birth up to 80% of the normal human plasma concentration. This demonstrates a very hopeful proof of principle for the development of prenatal treatment of many genetic diseases but also requires more detailed investigations with respect to the observed systemic spread of the vector. [ABSTRACT FROM AUTHOR]

The greatest body of scientific evidence has been accumulated for the simple ratio of the MCA-PI divided by the umbilical artery PI (i.e. the CPR), and the second most commonly utilized ratio is its inverse, i.e. the umbilical artery PI divided by the MCA-PI (umbilicocerebral ratio (UCR)). Second- and third-trimester uterine artery evaluation (Figure 2) GLO:F0Y/01aug21:uog23698-fig-0002.jpg PHOTO (COLOR): 2 Waveforms from uterine artery obtained transabdominally in second trimester. First-trimester uterine artery evaluation (Figure 1) GLO:F0Y/01aug21:uog23698-fig-0001.jpg PHOTO (COLOR): 1 Waveform from uterine artery obtained transabdominally in first trimester. gl 1. In Doppler waveforms showing dynamic changes in the systolic or diastolic components (i.e. in case of uterine artery waveform with presence of notching, or reversed EDV in umbilical artery waveform), PI gives a better estimate of the characteristics of the waveform than do RI or S/D ratio. [Extracted from the article]

Objectives: Observational studies have shown that low cerebroplacental ratio (CPR) values predict an increased risk of adverse perinatal outcome. The inverse ratio, i.e. the umbilicocerebral ratio (UCR), has been suggested to be a better predictor as it rises with increasing degree of fetal compromise. However, longitudinal reference ranges for UCR have not been established, and whether gestational-age-dependent changes in CPR or UCR differ between male and female fetuses has not been studied. Thus, the aims of this study were to investigate sex-specific, gestational-age-associated serial changes in CPR and UCR during the second half of pregnancy and to establish longitudinal reference ranges.Methods: This was a secondary analysis of prospectively collected data from a dual-center longitudinal observational cohort study of low-risk singleton pregnancies. Doppler blood-flow velocity waveforms were obtained serially from the umbilical artery (UA) and fetal middle cerebral artery (MCA) from 19-41 weeks' gestation, and pulsatility indices (PIs) were determined. CPR and UCR were calculated as the ratios MCA-PI/UA-PI and UA-PI/MCA-PI, respectively. The course and outcome of pregnancies were recorded, and the sex of the fetus was determined after delivery. Reference intervals for CPR and UCR were constructed using multilevel modeling, and gestational-age-specific Z-scores in male and female fetuses were compared.Results: Of a total of 299 pregnancies enrolled, 284 (148 male and 136 female fetuses) were included in the final analysis, and 979 paired measurements of UA-PI and MCA-PI were used to construct sex-specific longitudinal reference intervals. The relationship of both CPR and UCR with gestational age was U-shaped, but in opposite directions. There was a small but significant difference in Z-scores of CPR and UCR between male and female fetuses throughout the second half of pregnancy (P = 0.007).Conclusions: We have established longitudinal reference ranges for CPR and UCR suitable for serial monitoring, with the possibility of refining assessment by using fetal sex-specific ranges and conditioning by a previous measurement. The clinical significance of such refinements needs further evaluation. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Objectives We hypothesized that first-trimester Doppler ultrasonography can be carried out at lower output energies than the currently advocated limits without compromising clinically important information. Methods We recruited 42 pregnant women for an ultrasound examination at 12 weeks' gestation. Twenty-one women were examined with a transvaginal transducer, the rest with a transabdominal transducer. We used pulsed Doppler to measure pulsatility index (PI) and peak systolic velocity (PSV) in five clinically relevant fetal and maternal blood vessels. The energy indicator thermal index for bone (TIb) was set at 1.0, 0.5 and 0.1. Each measurement was repeated three times. A mixed linear regression model accounting for correlation between measurements was used to assess the effect of different TIb levels and transducers. Results We were able to visualize the vessels by color Doppler and measure PI and PSV in all vessels at all energy levels in all the participants with the exception of the ductus venosus in two participants, yielding 1872 recordings for statistical analysis. A reduction in TIb from 1.0 to 0.5 and 0.1 had no effect on the PI or PSV values, nor was there any trend towards higher parameter variance with decreasing TIb. There was no difference between measured values of PI and PSV between the transducers, but the transabdominal technique was associated with a greater parameter variance. Conclusion Reliable first-trimester Doppler data can be obtained with output energy reduced to a TIb of 0.5 or 0.1. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Objective Based on the hypothesis that fetal breathing movements (FBM) enhance sections of the circulation to meet the needs of gas transport, we studied the effects of FBM on the fetal inferior vena cava (IVC), which transports blood with the lowest oxygen saturation in the fetal body. Methods One-hundred and ten women with low-risk singleton pregnancies were included in a longitudinal study during the second half of pregnancy. Inner diameter, peak systolic velocity and time-averaged maximum blood velocity were measured in the IVC below the ductus venosus outlet during rest and FBM. Volume flow and pressure gradient were estimated in 55 observations of forced inspiratory movements at 36 weeks of gestation. The results are presented as mean and 95% CI of the mean. Results Based on 585 observations obtained during fetal rest and FBM, we found no difference in diameter, 0.42 (95% CI, 0.41-0.43) cm vs. 0.41 (95% CI, 0.39-0.42) cm, respectively, apart from during high-amplitude inspiratory movement, when the diameter was 0.15 (95% CI, 0.13-0.17) cm. The peak systolic velocity was different during rest and FBM, 34.0 (95% CI, 32.7-35.3) cm/s vs. 81.5 (95% CI, 76.2-87.5) cm/s, respectively, and correspondingly for time-averaged maximum velocity, 19.7 (95% CI, 18.9-20.5) cm/s vs. 37.2 (95% CI, 34.9-39.9) cm/s, respectively. Forced inspiratory movements at 36 weeks significantly reduced flow in the IVC compared with rest, 63.6 (95% CI, 44.4-88.1) mL/min vs. 186.0 (95% CI, 142.8-238.1) mL/min, respectively. The pressure gradient increased 14-fold during forced inspiration, from 0.64 to 8.76 mmHg. Conclusions High-amplitude fetal inspiration substantially constricts the abdominal IVC and creates a negative pressure in the chest. The IVC constriction withholds abdominal blood, thus temporarily giving way to other flows. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article presents a study that determines whether fetal breathing is responsible for increased umbilical blood flow. The study performed investigations to 110 women with low-risk singleton pregnancies, who undergoes three times of ultrasound for the second half of pregnancy, along with the examination of fetal heart rate, umbilical artery blood velocity, and blood flow. The study concludes that fetal breathing causes the increased umbilical blood flow during the second half of pregnancy.

The article discusses a study which aims to establish longitudinal reference ranges for fetal celiac and splenic arteries flow velocity and pulsatility index (PI). The study made Doppler recordings on several occasions to create reference ranges for blood velocity and PI measurements. The study found that longitudinal reference ranges fetal celiac and splenic arteries Doppler measurements are engaged in the maintenance of portal liver perfusion which is independent from the hepatic artery.

Objectives: Serial Doppler measurements of the ductus venosus are used increasingly for monitoring fetuses at risk of hemodynamic compromise, but existing reference ranges are based on cross-sectional studies and thus are less suitable for comparison with serial measurements. We aimed to establish longitudinal reference ranges for ductus venosus flow velocities and waveform indices and to provide the necessary terms for calculating conditional reference ranges for serial measurements. Methods: This was a longitudinal study of 160 low-risk pregnancies. Pulsed Doppler ultrasound was used to record ductus venosus blood flow velocities at 4-week intervals from 20-22 weeks of gestation onwards. Results: With a success rate of 93%, 547 measurements (four or five in each fetus) were used to establish reference ranges. The time-averaged maximum velocity was 50 cm/s at 21 weeks of gestation, increased to 60 cm/s at 32 weeks, and remained so until term. Similarly, the peak systolic velocity increased from 59 cm/s at 21 weeks to 71 cm/s at 31 weeks and remained so until term. The end-diastolic velocity showed a continuous increase from 31 cm/s at 21 weeks to 43 cm/s at 40 weeks. The pulsatility index for veins decreased from 0.57 at 21 weeks to 0.44 at 40 weeks. When conditioned by a previous measurement, the reference ranges for the next observation became narrower and commonly shifted compared with those of the entire population. Conclusion: The new longitudinal reference ranges presented here reflect the development of the ductus venosus flow velocities and velocity indices and are thus appropriate for serial measurements, particularly if conditional terms are included. [ABSTRACT FROM AUTHOR]

Objective: The turgor of Wharton's jelly depends on osmotic and hydrostatic pressures. We tested the hypothesis that umbilical ring constriction has an impact on umbilical venous hemodynamics and thus on the volume of Wharton's jelly. Methods: In a cross-sectional study of 237 low-risk singleton pregnancies, the cross-sectional area of the fetal end of the umbilical cord was determined using sonography at 20-41 weeks of gestation. The inner area of the two arteries and the vein was also measured and subtracted from the cord area to calculate the area of Wharton's jelly. Based on the Bernoulli equation, the degree of vein constriction at the umbilical ring was assessed using the blood velocity increment at the abdominal inlet. Regression analysis and SD-score statistics were used to construct mean values and to assess the effects. The dataset was also analyzed for gender-specific effects. Results: The umbilical cord cross-sectional area increased with gestational age during the period 20-31 weeks, remaining essentially stable thereafter. The Wharton's jelly increased with gestational age from 20 until 31-32 weeks of gestation and remained at the same level for the rest of the pregnancy. At mid-gestation, on average 70% of the cord cross-sectional area was occupied by Wharton's jelly; at 31 weeks and later this value was 60%. Umbilical vein constriction was associated with reduced umbilical cord cross-sectional area and Wharton's jelly in female fetuses (P = 0.0007 and P = 0.003, respectively), but not in male fetuses. Conclusions: Under physiological conditions, umbilical ring constriction affects umbilical vein hemodynamics, with corresponding effects on the umbilical cord cross-sectional area and the amount of Wharton's jelly. Interestingly, the effects are gender-specific. [ABSTRACT FROM AUTHOR]

Objective It has been suggested that constriction of the umbilical vein (UV) at the umbilical ring has hemodynamic effects. We aimed to determine the occurrence and extent of such constriction in serial observations. Methods This was a prospective longitudinal study of UV velocities at the umbilicus measured at approximately 4-week intervals between 19 and 42 weeks' gestation in 129 low-risk singleton pregnancies. Each participant was examined three to five times. Multilevel modeling was used to construct the reference ranges and to test associations between variables. Results Gestational age-specific reference percentiles of UV velocities at the umbilicus were established based on 469 observations. Fetuses were able to alter the UV velocities considerably during the second half of pregnancy, signifying a varying degree of UV constriction. Of a total of 129 fetuses, 56 (43.4%) never had high UV blood velocity (i.e. > 46 cm/s, the highest quartile), 42 (32.6%) fetuses had high UV blood velocity on one occasion and 31 (24.0%) fetuses on two or more occasions. In 36 (27.9%) fetuses the UV velocity at the umbilical ring was > 300% of the mean gestational age-specific reference value at the intra-abdominal section on at least one occasion. Constriction of the UV at the umbilical ring did not affect the pulsatility of the umbilical artery, and was not associated with adverse perinatal outcome in this study. Conclusions Low-risk fetuses may well constrict the UV at the abdominal wall with velocities extending over wide ranges on one or more occasions during the second half of pregnancy. Rather than being a risk for complications, the constriction seems to be part of physiological development and possibly a regulatory mechanism. [ABSTRACT FROM AUTHOR]

Objective To construct reference ranges for serial measurements of umbilical artery (UA) blood flow velocity and pulsatility index (PI) at standardized insonation sites during the second half of pregnancy. Methods This was a prospective longitudinal study of the umbilical circulation. UA blood flow velocities were measured at the intra-abdomninal portion, fetal end and placental end at 4-weekly intervals at 19–42 weeks of gestation in 130 low-risk singleton pregnancies. A total of 513 observations were used to construct the reference ranges using regression statistics and multilevel modeling. Results UA blood velocities and PI were higher at the intra-abdominal portion and fetal end than at the placental end. The gestational age-related increase of end-diastolic velocity was greater than the corresponding increase of the peak systolic velocity at all locations. The mean differences (delta values) of UA blood velocities between the fetal and placental ends increased and that of PI decreased with advancing gestational age. Conclusion UA Doppler parameters vary significantly at different locations. We have established new reference ranges for the UA velocities and PI at standardized locations based on longitudinal observations, which should be useful for the surveillance of fetuses with repeated observations. [ABSTRACT FROM AUTHOR]

Objectives: To construct reference ranges for serial measurements of the umbilical artery (UA) absolute blood flow velocities in the second half of pregnancy and to test the hypothesis that significant associations exist between UA velocities and placental volume blood flow assessed from umbilical vein blood flow velocities and diameter. Methods: This was a prospective longitudinal study of the umbilical circulation. UA absolute velocities and umbilical vein blood flow were measured at 4-weekly intervals between 19 and 42 weeks' gestation in 130 low-risk singleton pregnancies. A total of 511 observations were used to construct the reference ranges and assess the association between UA absolute velocities and placental volume flow using multilevel modeling. Results: Both UA absolute velocities and placental volume blood flow showed a steady increase throughout the second half of pregnancy. However, the gestational age-related increase in the UA end-diastolic velocity (EDV) was greater than the corresponding increase in the peak systolic velocity (PSV). The time-averaged intensity-weighted mean velocity (TAWMV)/time-averaged maximum velocity (TAMXV) was 0.6 indicating probably not a completely parabolic velocity profile. There was a significant positive association (P < 0.00001) between UA absolute velocities and placental volume blood flow, but this association was modified by the gestational age. The intraobserver coefficients of variation for the UA PSV, EDV, TAMXV and TAWMV and placental volume blood flow were 10.17%, 16.29%, 11.46%, 18.18% and 8.61%, respectively. Conclusion: We have established new reference ranges for the UA absolute velocities based on longitudinal data. They show a significant association with fetoplacental volume blood flow and may have a clinical value in the assessment of the umbilical circulation. [ABSTRACT FROM AUTHOR]

Introduction: Detection and surveillance of fetal growth restriction (FGR) is well established, but there is still room for improvement. Animal studies indicate that compromised fetuses increase adrenal blood flow. Modern ultrasound equipment allows us to measure vascular impedance in the fetal adrenal arteries despite their modest size. However, extensive anatomical variance is a challenge to standardizing measurements. We set out to improve this., Material and Methods: We included 75 low-risk pregnant women in a prospective cross-sectional study aiming to develop a reliable technique to visualize and measure flow velocity in human fetal adrenal arteries. We used commercially available ultrasound equipment: a GE Voluson 10 2019 with a C2-9 probe (GE Healthcare, Zipf, Austria), and a Philips Epiq Elite with a V9-2 probe (Philips Medical Systems International B.V., Best, The Netherlands), exploiting the modern sensitive power Doppler modes in both scanners to visualize small vessels., Results: Among 72 fetuses, the inferior adrenal artery was the most consistently visualized and measured artery to the gland. Doppler velocimetry was achieved in 66 (92%) participants. We found the anatomical variation described previously but were able to develop visualization strategies to identify the common arteries and use a consistent Doppler technique for the second half of pregnancy., Conclusions: It is possible to visualize and measure flow velocity in the adrenal arteries of human fetuses. The success rate was highest for the inferior adrenal artery making this vessel a candidate for clinical studies., (© 2024 The Author(s). Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).)

This longitudinal study investigated the impact of actigraphy-measured maternal physical activity on yolk sac size during early development. The yolk sac, a transient extraembryonic organ, plays a crucial role in embryonic development and is involved in metabolism, nutrition, growth, and hematopoiesis. Prospectively collected data from 190 healthy women indicated that their total daily physical activity, including both light and moderate-vigorous activity, was associated with yolk sac growth dynamics depending on embryonic sex and gestational age. Higher preconception maternal physical activity was linked to a larger yolk sac at 7 weeks (95% CI [0.02-0.13 mm]) and a smaller yolk sac at 10 weeks' gestation (95% CI [- 0.18 to - 0.00]) in male embryos; in female embryos, the yolk sac size was increased at 10 weeks' gestation (95% CI [0.06-0.26]) and was, on average, 24% larger than that in male embryos (95% CI [0.12-0.38]). Considering the pattern of other maternal effects on yolk sac size-e.g., body composition and sleep duration-we suggest that physiological yolk sac adaptations occur in short, sex-specific time windows and can be influenced by various maternal factors., (© 2023. The Author(s).)

Background: Fetal growth restricted (FGR) neonates have increased risk of circulatory compromise due to failure of normal transition of circulation after birth., Aim: Echocardiographic assessment of heart function in FGR neonates first three days after birth., Study Design: Prospective observational study., Subjects: FGR- and non-FGR neonates., Outcome Measures: M-mode excursions and pulsed-wave tissue Doppler velocities normalised for heart size and E/e' of the atrioventricular plane day one, two and three after birth., Results: Compared with controls (non-FGR of comparable gestational age, n = 41), late-FGR (gestational age ≥ 32 weeks, n = 21) exhibited higher septal excursion (15.9 (0.6) vs. 14.0 (0.4) %, p = 0.021) (mean (SEM)) and left E/e' (17.3 (1.9) vs.11.5 (1.3), p = 0.019). Relative to day three, indexes on day one were higher for left excursion (21 (6) % higher on day one, p = 0.002), right excursion (12 (5) %, p = 0.025), left e' (15 (7) %, p = 0.049), right a' (18 (6) %, p = 0.001), left E/e' (25 (10) %, p = 0.015) and right E/e' (17 (7) %, p = 0.013), whereas no index changed from day two to day three. Late-FGR had no impact on changes from day one and two to day three. No measurements differed between early-FGR (n = 7) and late-FGR., Conclusions: FGR impacted neonatal heart function the early transitional days after birth. Late-FGR hearts had increased septal contraction and reduced left diastolic function compared with controls. The dynamic changes in heart function between first three days were most evident in lateral walls, with similar pattern in late-FGR and non-FGR. Early-FGR and late-FGR exhibited similar heart function., Competing Interests: Declaration of competing interest None., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objective: Assess effects of fetal growth restriction (FGR) on cardiac modelling in premature and term neonates., Study Design: Prospective echocardiographic study of a cohort of FGR neonates (n = 21) and controls (n = 41) with normal prenatal growth and circulation., Results: Unadjusted for gestational age, birth weight, sex, and twin/singleton, Late-FGR neonates had smaller hearts than controls, with globular left ventricles and symmetrical right ventricles. Adjusted estimates showed smaller left ventricles and similarly sized right ventricles, with symmetrical left and right ventricles. Early-FGR (compared with Late-FGR) had smaller hearts and globular left ventricles in unadjusted estimates, but after adjustment, sizes and shapes were similar., Conclusion: FGR had significant impact on cardiac modelling, seen in both statistical models unadjusted and adjusted for gestational age, birth weight, sex, and twin/singleton. The adjustments, however, refined the results and revealed more specific effects of FGR, thus underscoring the importance of statistical adjustments in such studies., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

The concept of developmental origin of health and disease has ignited a search for mechanisms and health factors influencing normal intrauterine development. Sleep is a basic health factor with substantial individual variation, but its implication for early prenatal development remains unclear. During the embryonic period, the yolk sac is involved in embryonic nutrition, growth, hematopoiesis, and likely in fetal programming. Maternal body measures seem to influence its size in human female embryos. In this prospective, longitudinal observational study of 190 healthy women recruited before natural conception, we assessed the effect of prepregnant sleep duration (actigraphy) on the fetal crown-rump-length (CRL) and yolk sac size (ultrasound). All women gave birth to a live child. The prepregnancy daily sleep duration had an effect on the male yolk sac and CRL at the earliest measurement only (7 weeks). I.e., the yolk sac diameter decreased with increasing sleep duration (0.22 mm·h -1 d -1 , 95%CI [0.35-0.09], P < 0.01), and CRL increased (0.92 mm·h -1 d -1 , 95%CI [1.77-0.08], P = 0.03). Since there was no association at the second measurement (10 weeks), and in the group of female fetuses at any measure point, we suggest a sex- and time-dependent embryonic adaptation to sleep generated differences in the intrauterine environment in normal pregnancies., (© 2022. The Author(s).)

This study reviewed the literature about the diagnosis, antepartum surveillance, and time of delivery of fetuses suspected to be small for gestational age or growth restricted. Several guidelines have been issued by major professional organizations, including the International Society of Ultrasound in Obstetrics and Gynecology and the Society for Maternal-Fetal Medicine. The differences in recommendations, in particular about Doppler velocimetry of the ductus venosus and middle cerebral artery, have created confusion among clinicians, and this review has intended to clarify and highlight the available evidence that is pertinent to clinical management. A fetus who is small for gestational age is frequently defined as one with an estimated fetal weight of <10th percentile. This condition has been considered syndromic and has been frequently attributed to fetal growth restriction, a constitutionally small fetus, congenital infections, chromosomal abnormalities, or genetic conditions. Small for gestational age is not synonymous with fetal growth restriction, which is defined by deceleration of fetal growth determined by a change in fetal growth velocity. An abnormal umbilical artery Doppler pulsatility index reflects an increased impedance to flow in the umbilical circulation and is considered to be an indicator of placental disease. The combined finding of an estimated fetal weight of <10th percentile and abnormal umbilical artery Doppler velocimetry has been widely accepted as indicative of fetal growth restriction. Clinical studies have shown that the gestational age at diagnosis can be used to subclassify suspected fetal growth restriction into early and late, depending on whether the condition is diagnosed before or after 32 weeks of gestation. The early type is associated with umbilical artery Doppler abnormalities, whereas the late type is often associated with a low pulsatility index in the middle cerebral artery. A large randomized clinical trial indicated that in the context of early suspected fetal growth restriction, the combination of computerized cardiotocography and fetal ductus venosus Doppler improves outcomes, such that 95% of surviving infants have a normal neurodevelopmental outcome at 2 years of age. A low middle cerebral artery pulsatility index is associated with an adverse perinatal outcome in late fetal growth restriction; however, there is no evidence supporting its use to determine the time of delivery. Nonetheless, an abnormality in middle cerebral artery Doppler could be valuable to increase the surveillance of the fetus at risk. We propose that fetal size, growth rate, uteroplacental Doppler indices, cardiotocography, and maternal conditions (ie, hypertension) according to gestational age are important factors in optimizing the outcome of suspected fetal growth restriction., (Copyright © 2022. Published by Elsevier Inc.)

Objectives: To assess how maternal body mass index and gestational weight gain are related to on fetal venous liver flow and birthweight in pregnancies with pre-gestational diabetes mellitus., Methods: In a longitudinal observational study, 49 women with pre-gestational diabetes mellitus were included for monthly assessments (gestational weeks 24-36). According to the Institute Of Medicine criteria, body mass index was categorized to underweight, normal, overweight, and obese, while gestational weight gain was classified as insufficient, appropriate or excessive. Fetal size, portal flow, umbilical venous flow and distribution to the fetal liver or ductus venosus were determined using ultrasound techniques. The impact of fetal venous liver perfusion on birthweight and how body mass index and gestational weight gain modified this effect, was compared with a reference population (n = 160)., Results: The positive association between umbilical flow to liver and birthweight was more pronounced in pregnancies with pre-gestational diabetes mellitus than in the reference population. Overweight and excessive gestational weight gain were associated with higher birthweights in women with pre-gestational diabetes mellitus, but not in the reference population. Fetuses of overweight women with pre-gestational diabetes mellitus had higher umbilical (p = 0.02) and total venous liver flows (p = 0.02), and a lower portal flow fraction (p = 0.04) than in the reference population. In pre-gestational diabetes mellitus pregnancies with excessive gestational weight gain, the umbilical flow to liver was higher than in those with appropriate weight gain (p = 0.02)., Conclusions: The results support the hypothesis that umbilical flow to the fetal liver is a key determinant for fetal growth and birthweight modifiable by maternal factors. Maternal pre-gestational diabetes mellitus seems to augment this influence as shown with body mass index and gestational weight gain., Competing Interests: The authors have declared that no competing interests exist.

Introduction: In the fetus, a large proportion of the superior vena cava blood flow (Q SVC ) comes from the brain. To provide the possibility of using this blood flow as a representation of fetal brain circulation, we aimed to determine the fetal Q SVC and its fraction of cardiac output during the second half of physiological pregnancies. Materials and Methods: This was a prospective longitudinal study specifically designed for studying fetal hemodynamic development. Healthy women with singleton low-risk pregnancies were included. Ultrasonography was performed at 4-weekly intervals from 20 +0 gestational weeks to term. Doppler velocity recordings of the superior vena cava (SVC) and cardiac ventricular outflow tracts were used to obtain the time-averaged maximum velocities (TAMxV). Vessel diameters were measured to calculate their cross-sectional areas (CSA): π(diameter/2) 2 . Blood flow (Q) was computed as: h * TAMxV * CSA, h being the spatial blood velocity profile, to obtain Q SVC and cardiac outputs. The sum of left and right ventricular cardiac outputs constituted the combined cardiac output (CCO). Ultrasound biometry based estimated fetal weight and brain weight were used to normalize the flow. Q SVC was also expressed as the fraction (%) of CCO. Gestational age specific percentiles were established for each blood flow parameter using multilevel modeling. Results: Totally, 134 of the 142 included women were eligible for the study with 575 sets of observations. The SVC mean diameter (19-52 mm), mean TAMxV (8.83-16.14 cm/s), and Q SVC (15.4-192.0 ml/min) increased significantly during the second half of pregnancy ( p < 0.001) while the mean Q SVC normalized by estimated fetal weight (49 ml/min/kg) and by estimated brain weight (50 ml/min/100 g) were relatively stable. Similarly, the mean CCO increased (156-1,776 ml/min; p < 0.001) while the normalized CCO (509 ± 13 ml/min/kg) and Q SVC as a fraction of CCO (10 ± 0.92%) did not change significantly with gestational age. Conclusion: We provide reference values for fetal Q SVC which increases significantly with gestation, and constitutes roughly 10% of the fetal CCO at any time during the second half of pregnancy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Stefopoulou, Johnson, Herling, Lindgren, Kiserud and Acharya.)

Background: Sleep and physical activity changes are common in pregnancy, but longitudinal data starting before conception are scarce. Our aim was to determine the changes of the daily total sleep time (TST) and physical activity duration (PAD) from before conception to end of pregnancies in respect of pregestational maternal factors., Methods: This longitudinal observational study formed part of the CONIMPREG research project and recruited healthy women planning to become pregnant. Sleep and physical activity were recorded around-the-clock for ≥4 days via actigraphy before conception and during each trimester of pregnancy. Data were adjusted according to pregestational maternal body composition, parity and age., Results: Among 123 women with eligible data, the unadjusted mean (95% confidence interval) TST increased from 415.3 min (405.5-425.2 min) before conception to 458.0 min (445.4-470.6 min) in the 1 st trimester, remaining high through the 2 nd and 3 rd trimesters. Variation was substantial before conception (±2SD range: 307-523 min). The unadjusted mean PAD before conception was 363.7 min (±2SD range: 120-608 min), decreasing sharply to 262.1 min in the first trimester and more gradually thereafter. Vigorous and moderate activity decreased more than light activity. TST and PAD were significantly associated with age, parity, and pregestational body fat percentage; lean body mass was negatively correlated with TST. Results were generally unaffected by seasonal variations., Conclusion: Marked variations were found in pregestational TST and PAD. Healthy women slept ≥30 min longer during pregnancy, while PAD decreased by ≥ 90 min in early pregnancy and continued to decrease thereafter., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Fetal superior vena cava (SVC) is essentially the single vessel returning blood from the upper body to the heart. With approximately 80-85% of SVC blood flow representing cerebral venous return, its interrogation may provide clinically relevant information about fetal brain circulation. However, normal reference values for fetal SVC Doppler velocities and pulsatility index are lacking. Our aim was to establish longitudinal reference intervals for blood flow velocities and pulsatility index of the SVC during the second half of pregnancy., Methods: This was a prospective study of low-risk singleton pregnancies. Serial Doppler examinations were performed approximately every 4 weeks to obtain fetal SVC blood velocity waveforms during 20-41 weeks. Peak systolic (S) velocity, diastolic (D) velocity, time-averaged maximum velocity (TAMxV), time-averaged intensity-weighted mean velocity (TAMeanV), and end-diastolic velocity during atrial contraction (A-velocity) were measured. Pulsatility index for vein (PIV) was calculated., Results: SVC blood flow velocities were successfully recorded in the 134 fetuses yielding 510 sets of observations. The velocities increased significantly with advancing gestation: mean S-velocity increased from 24.0 to 39.8 cm/s, D-velocity from 13.0 to 19.0 cm/s, and A-velocity from 4.8 to 7.1 cm/s. Mean TAMxV increased from 12.7 to 23.1 cm/s, and TAMeanV from 6.9 to 11.2 cm/s. The PIV remained stable at 1.5 throughout the second half of pregnancy., Conclusions: Longitudinal reference intervals of SVC blood flow velocities and PIV were established for the second half of pregnancy. The SVC velocities increased with advancing gestation, while the PIV remained stable from 20 weeks to term.

Introduction: Cerebroplacental ratio (CPR) and umbilicocerebral ratio (UCR) are clinically used as a measure of fetal brain sparing. These are calculated as the ratios between the pulsatility indices (PIs) of middle cerebral (MCA) and umbilical (UA) arteries, and are an indirect representation of the balance between cerebral and placental perfusion. Volume blood flow (Q)-based ratios, ie Q-CPR or Q-UCR, would directly reflect the distribution of fetal cardiac output to the placenta and brain. Thus, we aimed to determine the development pattern of Q-CPR and Q-UCR during the second half of pregnancy, construct reference intervals, and evaluate their association with CPR and UCR., Material and Methods: In a longitudinal cohort study of low-risk pregnancies, the inner diameter of the fetal superior vena cava (SVC) and umbilical vein (UV) was measured and velocity waveforms were obtained from the MCA, UA, UV and SVC using ultrasound at approximately 4-weekly intervals from 20 to 41 weeks. The CPR was calculated as PI MCA /PI UA and the inverse ratio was the UCR. Cerebral and placental blood flows were estimated as the product of mean velocity and cross-sectional area of the SVC and UV, respectively. Q-CPR was calculated as Q SVC /Q UV and the inverse as the Q-UCR. Gestational age-specific reference intervals were calculated and associations between variables were tested using multilevel regression modeling., Results: Longitudinal reference intervals of Q-CPR and Q-UCR were established based on 471 paired measurements of Q SVC and Q UV obtained serially from 134 singleton pregnancies. The mean Q-CPR increased from 0.4 to 0.8 during the second half of pregnancy and Q-UCR declined from 2.5 to 1.3, while the CPR and UCR had U-shaped curves but in opposite directions. No significant correlation was found between CPR and Q-CPR (R = 0.10; P = .051), or UCR and Q-UCR (R = 0.09; P = .11), and the agreement between PI-based and Q-based indices of fetal brain sparing was poor., Conclusions: Indices of fetal brain sparing based on placental and cerebral volume blood flow differ from those calculated from UA and MCA PIs. They correlated poorly with conventional CPR and UCR, indicating that they may provide additional/different physiological information. Reference values of Q-CPR and Q-UCR established here can be useful to investigate their clinical value further., (© 2020 The Authors. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).)

Background: Gynaecological fistulae cause urinary and/or faecal incontinence. Haukeland University Hospital has systematically recorded treatments for gynaecological fistulae, since 2012 in its capacity as the Norwegian National Unit for Gynaecological Fistulae. This study describes characteristics of and therapeutic outcomes for gynaecological fistulae caused by surgery and/or radiotherapy., Material and Method: We have conducted a retrospective cohort study of women who were treated at the Department of Gynaecology and Obstetrics, Haukeland University Hospital, in the period 1995-2019 for gynaecological fistulae due to surgery or radiotherapy., Results: Surgery or radiotherapy was the cause of gynaecological fistulae in 182 of a total of 411 women. 163 of them consented to the study, 124/163 (76 %) with fistulae following surgery and 39/163 (24 %) with fistulae following radiotherapy. The post-surgical fistulae were mainly urogenital (91/124: 73 %) and most often caused by a hysterectomy (n = 71) or urinary incontinence procedure (n = 11). Post-radiotherapy fistulae were mainly enterogenital (34/39: 87 %), with rectal cancer (n = 22) and cervical cancer (n = 11) as the most frequent types of cancer. The main procedure was vaginal fistuloplasty, which was carried out on 100/124 (81 %) of women with post-surgical fistula and 7/39 (18 %) of those with post-radiotherapy fistula. Catheter drainage or stomy alone resulted in healing in 14/163 (9 %) of all patients. A total of 117/124 (94 %) of women with post-surgical fistula achieved healing, compared with 10/39 (26 %) with post-radiotherapy fistula. 28/39 (72 %) of the latter had a permanent urostomy or enterostomy., Interpetation: Gynaecological fistulae caused by surgery have a good healing rate, while post-radiotherapy fistulae are more often permanent.

Introduction: Gynecological fistula (affecting female genital organs) leads to involuntary loss of urine or feces. In industrialized societies, fistulas occur mostly as complications of surgery, radiation therapy or inflammatory bowel disease. We sought to determine the incidence of gynecological fistula and type of surgical treatment provided in Norway., Material and Methods: This was a retrospective national cohort study of women treated for gynecological fistula (International Classification of Disease-10 code N82) during 2008-2014, identified from the mandatory Norwegian Patient Registry. To compare groups, we utilized Chi-square or non-parametric tests., Results: In all, 1627 women (.06% of the female Norwegian population) had 4475 hospital admissions with a diagnosis of gynecological fistula. In total, 1214/1627 (75%) had fistula as the main diagnosis: 346 (29%) a urogenital fistula, 672 (55%) an enterogenital, 38 (3%) a genitocutaneous and 22 (2%) both urinary and enteral fistula. Surgery for gynecological fistula was performed in 723 women, an incidence rate of 4.2 per 100 000 person-years (95% confidence interval [CI] 4.2-4.3); gynecological procedures (mostly vaginal/perineal) were performed in 163 women (23%), urological in 43 (6%), enteral in 267 (37%) and surgery involving multiple pelvic compartments in 250 (35%). Women undergoing fistula surgery had a median of three hospital contacts (95% CI 3-3), for 370 women (52%), the procedure was performed by a gynecologist, and 212 of these (29%) were also operated by urologists or gastroenterologists., Conclusions: Gynecological fistula is rare in Norway, with an overall incidence of 6/10 000 in the female population, whereas the incidence of surgically treated fistula is 4.2/100 000. However, the condition represents considerable morbidity for the individual patient., (© 2019 Nordic Federation of Societies of Obstetrics and Gynecology.)

Circadian rhythmicity is fundamental to human physiology, and is present even during fetal life in normal pregnancies. The impact of maternal endocrine disease on the fetal circadian rhythm is not well understood. The present study aimed to determine the fetal circadian rhythm in pregnancies complicated by pregestational diabetes mellitus (PGDM), compare it with a low-risk reference population, and identify the effects of maternal glycemic control and morning cortisol concentrations. Long-term fetal electrocardiogram recordings were made in 40 women with PGDM at 28 and 36 weeks of gestation. Two recordings were made in 18 of the women (45.0%) and one recording was made in 22 (55.0%). The mean fetal heart rate (fHR) and the fHR variation (root mean square of squared differences) were extracted in 1-min epochs, and circadian rhythmicity was detected by cosinor analysis. The study cohort was divided based on HbA1c levels and morning cortisol concentrations. Statistically, significant circadian rhythms in the fHR and the fHR variation were found in 45 (100%) and 44 (95.7%) of the 45 acceptable PGDM recordings, respectively. The rhythms were similar to those of the reference population. However, there was no statistically significant population-mean rhythm in the fHR among PGDM pregnancies at 36 weeks, indicating an increased interindividual variation. The group with higher HbA1c levels (>6.0%) had no significant population-mean fHR rhythm at 28 or 36 weeks, and no significant fHR-variation rhythm at 36 weeks. Similarly, the group with a lower morning cortisol concentration (≤8.8 µg/dl) had no significant population-mean fHR-variation rhythm at 28 and 36 weeks. These findings indicate that individual fetal rhythmicity is present in pregnancies complicated by PGDM. However, suboptimal maternal glycemic control and a lower maternal morning cortisol concentration are associated with a less-well-synchronized circadian system of the fetus.

Background: Pregestational diabetes is associated with fetal macrosomia, and umbilical perfusion of the fetal liver has a role in regulating fetal growth. We therefore hypothesized that pregestational diabetes alters fetal liver blood flow depending on degree of glycemic control., Methods: In a prospective study, 49 women with pregestational diabetes underwent monthly ultrasound examinations during 24-36 gestational weeks. Blood flow was determined in the umbilical vein, ductus venosus and portal vein, and blood velocity was measured in the left portal vein, the latter reflecting the watershed between splanchnic and umbilical flow. The measurements were compared with reference values by z-score statistics, and the effect of HbA1c assessed., Results: The umbilical venous flow to the liver (z-score 0.36, p = 0.002), total venous liver flow (z-score 0.51, p<0.001) and left portal vein blood velocity (z-score 0.64, p<0.001), were higher in the study group. Normalized portal venous flow was lower (z-score -0.42, p = 0.002), and normalized total venous liver flow tended to be lower after 30 gestational weeks (z-score -0.54, p = 0.047) in the diabetic pregnancies compared with reference values from a low-risk population. The left portal vein blood velocity was positively, and the portal fraction of total venous liver flow negatively correlated with first trimester HbA1C., Conclusions: In spite of increased umbilical blood distribution to the fetal liver, graded according to glycemic control, the total venous liver flow did not match third trimester fetal growth in pregnancies with pregestational diabetes, thus contributing towards increased perinatal risks and possibly altered liver function with long-term metabolic consequences., Competing Interests: The authors have declared that no competing interests exist.

Introduction: The human yolk sac provides the embryo with stem cells, nutrients, and gas exchange. We hypothesized that more maternal resources, reflected in body size and body composition, would condition a a larger yolk sac, ensuring resources for the growing embryo. Thus, we aimed to determine the relation between maternal size in early pregnancy and yolk sac size., Material and Methods: This subsidiary study was embedded in the multinational World Health Organization fetal growth project that included healthy women with a body mass index of 18-30, reliable information of their regular last menstrual period and singleton pregnancies. Yolk sac diameter, crown-rump length, and maternal height, weight, body mass index, and body composition were assessed before 13 weeks of gestation, and the fetal biometry was repeated during the pregnancy., Results: Of 140 participants, 122 with a successful yolk sac measurement were entered in the present analysis. Maternal weight was negatively associated with the yolk sac diameter (P = 0.007) and so was maternal height (P = 0.011), fat mass (P = 0.037), and lean body mass (P = 0.018), but not body mass index (P = 0.121). Significant effects were predominantly due to the female embryos and could be traced at 24 weeks of gestation. That is, a small yolk sac : crown-rump length ratio in early pregnancy was associated with a high fetal abdominal circumference (P < 0.001) and estimated fetal weight (P = 0.001)., Conclusions: The human yolk sac is involved in the regulation of embryonic growth, but contrary to our hypothesis, the yolk sac has a compensatory capacity, being larger when the mothers are smaller; and the effect can be traced on fetal size at 24 weeks of gestation., (© 2018 Nordic Federation of Societies of Obstetrics and Gynecology.)

Introduction: Fetal biometry is used for determining gestational age and estimated date of delivery (EDD). However, the accuracy of the EDD depends on the assumed length of pregnancy included in the calculation. This study aimed at assessing the actual pregnancy length and accuracy of EDD prediction based on fetal head circumference measured at the second trimester., Material and Methods: This was a population-based observational study with the following inclusion criteria: singleton pregnancy, head circumference dating in the second trimester, spontaneous onset or induction of delivery ≥ 294 days of gestation, live birth. The EDD was set anticipating a pregnancy length of 282 days. Bias in the prediction of EDD was defined as the difference between the actual date of birth and the EDD., Results: Head circumference measurements were available for 21 451 pregnancies. Ultrasound-dated pregnancies had a median pregnancy length of 283.03 days, corresponding to a method bias of 1.03 days (95% CI; 0.89-1.16). This bias was dependent on the head circumference at dating, ranging from -1.58 days (95% CI; -3.54 to 1.12) to 3.42 days (95% CI; 1.98-4.31). The median pregnancy length, based on the last menstrual period of women with a regular menstrual cycle (n = 12 985), was 283.15 days (95% CI; 282.91-283.31). A total of 5685 (22.9%, 95% CI; 22.4% to 23.4%) and 886 women (3.6%, 95% CI; 3.3%-3.8%) were still pregnant 7 and 14 days after the EDD, respectively., Conclusions: Second trimester head circumference measurements can be safely used to predict EDD. A revision of the pregnancy length to 283 days will reduce the bias of EDD prediction to a level comparable with other methods., (© 2018 Nordic Federation of Societies of Obstetrics and Gynecology.)