Antenatal visualization of the caudo-thalamic groove at expert fetal neurosonography.

OBJECTIVE: to describe the normal features of the caudo-thalamic groove at antenatal brain ultrasound in a group of structurally normal fetuses at third trimester and to report a small series of cases with abnormal appearance of the caudothalamic groove at antenatal brain ultrasound. METHODS: This was an observational study conducted at two referral Fetal Medicine units. A non-consecutive cohort of pregnant women with a singleton non anomalous pregnancy were prospectively recruited and underwent 3D ultrasound of the fetal brain at 28-32 weeks. At offline analysis the ultrasound volumes were adjusted in the multiplanar mode according to a standardized methodology, until the caudothalamic groove was visible on the parasagittal plane. To evaluate the inter-observer agreement, two operators were independently asked to indicate if the caudothalamic groove was visible unilaterally or bilaterally on each volume. The digital archives of the two Centres were also retrospectively searched to retrieve cases with abnormal findings at the level of the caudothalamic groove at antenatal brain ultrasound which were postnatally confirmed. RESULTS: 180 non-consecutive cases fulfilling the inclusion criteria were prospectively included. At offline analysis of the 3D US volumes the caudo-thalamic groove was identified on the parasagittal plane by both operators at least unilaterally in 176 cases (97.8%) and bilaterally in 174 cases (96.6%). The K-coefficient for the agreement between the two independent operators in recognizing the caudo-thalamic groove was 0.89 and 0.83 on one and both hemispheres respectively. At the retrospective search of our archives 5 cases with abnormal appearance of the groove at antenatal brain ultrasound (2 haemorrhage and 3 cyst) were found. CONCLUSION: Our study has demonstrated that the caudo-thalamic groove is consistently seen among normal fetuses at third trimester submitted to multiplanar neurosonography and that abnormal findings at this level may be antenatally detected. This article is protected by copyright. All rights reserved.

Diagnostic accuracy of prenatal ultrasound in coarctation of aorta: systematic review and individual participant data meta-analysis.

OBJECTIVE: To determine the diagnostic accuracy of prenatal ultrasound in detecting coarctation of the aorta (CoA). METHODS: An individual participant data meta-analysis was performed to report on the strength of association and diagnostic accuracy of different ultrasound signs in detecting CoA prenatally. MEDLINE, EMBASE and CINAHL were searched for studies published between January 2000 and November 2021. Inclusion criteria were fetuses with suspected isolated CoA, defined as ventricular and/or great vessel disproportion with right dominance on ultrasound assessment. Individual participant-level data were obtained by two leading teams. PRISMA-IPD and PRISMA-DTA guidelines were used for extracting data, and the QUADAS-2 tool was used for assessing quality and applicability. The reference standard was CoA, defined as narrowing of the aortic arch, diagnosed after birth. The most commonly evaluated parameters on ultrasound, both in B-mode and on Doppler, constituted the index test. Summary estimates of sensitivity, specificity, diagnostic odds ratio (DOR) and likelihood ratios were computed using the hierarchical summary receiver-operating-characteristics model. RESULTS: The initial search yielded 72 studies, of which 25 met the inclusion criteria. Seventeen studies (640 fetuses) were included. On random-effects logistic regression analysis, tricuspid valve/mitral valve diameter ratio > 1.4 and > 1.6, aortic isthmus/arterial duct diameter ratio < 0.7, hypoplastic aortic arch (all P < 0.001), aortic isthmus diameter Z-score of < -2 in the sagittal (P = 0.003) and three-vessel-and-trachea (P < 0.001) views, pulmonary artery/ascending aorta diameter ratio > 1.4 (P = 0.048) and bidirectional flow at the foramen ovale (P = 0.012) were independently associated with CoA. Redundant foramen ovale was inversely associated with CoA (P = 0.037). Regarding diagnostic accuracy, tricuspid valve/mitral valve diameter ratio > 1.4 had a sensitivity of 72.6% (95% CI, 48.2-88.3%), specificity of 65.4% (95% CI, 46.9-80.2%) and DOR of 5.02 (95% CI, 1.82-13.9). The sensitivity and specificity values were, respectively, 75.0% (95% CI, 61.1-86.0%) and 39.7% (95% CI, 27.0-53.4%) for pulmonary artery/ascending aorta diameter ratio > 1.4, 47.8% (95% CI, 14.6-83.0%) and 87.6% (95% CI, 27.3-99.3%) for aortic isthmus diameter Z-score of < -2 in the sagittal view and 74.1% (95% CI, 58.0-85.6%) and 62.0% (95% CI, 41.6-78.9%) for aortic isthmus diameter Z-score of < -2 in the three-vessel-and-trachea view. Hypoplastic aortic arch had a sensitivity of 70.0% (95% CI, 42.0-88.6%), specificity of 91.3% (95% CI, 78.6-96.8%) and DOR of 24.9 (95% CI, 6.18-100). The diagnostic yield of prenatal ultrasound in detecting CoA did not change significantly when considering multiple categorical parameters. Five of the 11 evaluated continuous parameters were independently associated with CoA (all P < 0.001) but all had low-to-moderate diagnostic yield. CONCLUSIONS: Several prenatal ultrasound parameters are associated with an increased risk for postnatal CoA. However, diagnostic accuracy is only moderate, even when combinations of parameters are considered. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Normal and abnormal appearance of fetal ganglionic eminence on second-trimester three-dimensional ultrasound.

OBJECTIVES: To describe the appearance and size of the ganglionic eminence (GE) in normal fetuses on midtrimester three-dimensional (3D) neurosonography and to report on the association between GE alterations (cavitation or enlargement) and malformation of cortical development (MCD). METHODS: This was a prospective multicenter cohort study of normal fetuses and a retrospective analysis of pathological cases with MCD. From January 2022 to June 2022, patients attending our tertiary centers for an expert fetal brain scan were recruited for the purpose of the study. A 3D volume of the fetal head, starting from the sagittal plane, was acquired in apparently normal fetuses using a transabdominal or transvaginal approach. Stored volume datasets were then evaluated independently by two expert operators. Two measurements (longitudinal diameter and transverse diameter) of the GE in the coronal view were obtained twice by each operator. Intra- and interobserver measurement variation was calculated. Reference ranges for GE measurements were calculated in the normal population. A previously stored volume dataset of 60 cases with MCD was also analyzed independently by the two operators using the same method in order to assess if GE abnormalities (cavitation or enlargement) were present. Postnatal follow-up was obtained in all cases. RESULTS: In the study period, 160 normal fetuses between 19 and 22 weeks of gestation were included in the study. The GE was visible in the coronal plane on 3D neurosonography in 144 (90%) cases and was not clearly visible in the remaining 16 (10%) cases. The intra- and interobserver agreement was almost perfect for the longitudinal diameter, with an intraclass correlation coefficient (ICC) of 0.90 (95% CI, 0.83-0.93) and 0.90 (95% CI, 0.86-0.92), respectively, and substantial for the transverse diameter, with an ICC of 0.80 (95% CI, 0.70-0.87) and 0.64 (95% CI, 0.53-0.72), respectively. A retrospective analysis of 50 cases with MCD in the second trimester showed that GE enlargement was present in 12 cases and GE cavitation was present in four cases. CONCLUSIONS: Systematic assessment of the GE in fetuses at 19-22 weeks of gestation is feasible on 3D neurosonography, with good reproducibility in normal cases. Cavitation or enlargement of the GE can be demonstrated in fetuses with MCD. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Appearance of fetal posterior fossa at 11-14 weeks in fetuses with Dandy-Walker malformation or chromosomal anomalies.

OBJECTIVE: To describe the sonographic appearance of fetal posterior fossa anatomy at 11-14 weeks of pregnancy and to assess the outcome of fetuses with increased intracranial translucency (IT) and/or brainstem-to-occipital bone (BSOB) diameter. METHODS: Reference ranges for brainstem (BS), IT and cisterna magna (CM) measurements, BSOB diameter and the BS : BSOB ratio were obtained from the first-trimester ultrasound examination of 233 fetuses with normal postnatal outcome (control group). The intraobserver and interobserver variability of measurements were investigated using 73 stored ultrasound images. In addition, a study group of 17 fetuses with increased IT and/or BSOB diameter was selected to assess outcome. RESULTS: No significant intraobserver or interobserver variability was found for any measurement in the control group. In the study group, IT was increased in all cases and BSOB diameter was above the 95(th) centile of the calculated normal range in all but two (88%) cases. In 13/17 study cases, only two of the three posterior brain spaces were recognized on ultrasound. These 13 fetuses had a larger BSOB diameter than did the four cases that showed all three posterior brain spaces, and had severe associated anomalies including Dandy-Walker malformation (DWM) and/or chromosomal anomalies. CONCLUSIONS: Visualization of the fetal posterior fossa anatomy at 11-14 weeks' gestation is feasible. Increased fluid in the posterior brain at 11-14 weeks, particularly in the case of non-visibility of the septation that divides the future fourth ventricle from the CM, is an important risk factor for cystic posterior fossa malformations, in particular DWM, and/or chromosomal aberrations. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

The hippocampal commissure: a new finding at prenatal 3D ultrasound in fetuses with isolated complete agenesis of the corpus callosum.

OBJECTIVE: The aim of this research was to determine the prevalence and sonographic appearance of the hippocampal commissure in fetuses with isolated complete agenesis of the corpus callosum by three-dimensional neurosonography in the multiplanar mode. METHODS: This was a multicenter observational study. Stored volume datasets of fetuses with isolated complete agenesis of the corpus were retrospectively retrieved for analysis in three tertiary centers. The presence or absence of the hippocampal commissure was independently evaluated in the coronal and midsagittal planes by two operators. Postnatal follow-up was obtained in all cases. RESULTS: From November 2007 to February 2013, 41 cases between 19 and 30 weeks of gestation were retrieved for analysis. The hippocampal commissure was visible in the coronal and sagittal planes in 27/41 (65.8%), absent or not clearly recognizable in the remaining 14 cases. The qualitative analysis of the two operators was concordant in 100% of cases. CONCLUSIONS: In more than half of fetuses with complete callosal agenesis, the hippocampal commissure may be visualized at prenatal ultrasound. This is a residual interhemispheric connection, which in normal cases is hidden by the corpus callosum itself. Further research is needed to establish if this has an impact on postnatal outcome.

Open fourth ventricle prior to 20 weeks' gestation: a benign finding?

OBJECTIVE: To evaluate the role of the brainstem-vermis (BV) angle in the diagnosis of fetal posterior fossa abnormalities at 15-18 weeks' gestation. METHODS: We examined retrospectively three-dimensional (3D) ultrasound volumes acquired at 15-18 gestational weeks in fetuses with normal posterior fossa (controls) and in those with cystic posterior fossa. Whether the fourth ventricle appeared open posteriorly in axial views was noted and the BV angle was measured. A detailed follow-up was obtained in all cases. RESULTS: Of the 139 controls, 46 cases were excluded because of inadequate quality of the 3D volumes. Of the 93 remaining normal fetuses, 84 (90.3%) had a closed fourth ventricle and a BV angle < 20°, whereas 9/93 (9.7%) had an open fourth ventricle and a BV angle between 20° and 37°. The study group of 11 fetuses included seven with Dandy-Walker malformation and four with Blake's pouch cyst. In abnormal cases as a whole, the BV angle was significantly increased compared with that in controls (P < 0.0001). However, fetuses with Blake's pouch cyst and normal fetuses with an open fourth ventricle had strikingly similar sonograms: the BV angle was between 20° and 37° and the fourth ventricle appeared open only when viewed using a more steeply angulated scanning plane than that of the standard transcerebellar plane; in fetuses with Dandy-Walker malformation the fourth ventricle was widely open posteriorly, even in the standard transcerebellar view, and the BV angle was > 45°, significantly increased compared both with that in normal fetuses (P < 0.0001) and with that in fetuses with Blake's pouch cyst (P = 0.004). CONCLUSION: An open fourth ventricle is found in about 10% of normal fetuses at 15-18 weeks' gestation. Measurement of the BV angle is useful in such cases, as a value ≥ 45° is associated with a very high risk of severe posterior fossa malformation.

Ultrasound diagnosis of placental and umbilical cord anomalies in singleton pregnancies resulting from in-vitro fertilization.

INTRODUCTION: placental anomalies can affect fetal and maternal outcome due to severe maternal hemorrhage potentially resulting in hysterectomy and cord accident including abruption that can determine fetal damage or death. The aims of our study are to determine if the rate of placental and umbilical cord anomalies are more common in IVF singleton pregnancies compared to spontaneous pregnancies; to evaluate the role of ultrasound in screening for these anomalies and to investigate if oocyte donor fertilization is an additional risk factor for the development of these anomalies. METHODS: this was a prospective cohort study involving two tertiary centers. Patients with a singleton pregnancy conceived with IVF and patients presenting with a spontaneous conception were recruited between 1st May 2019 to 31st March 2021. A total of 634 pregnancies were enrolled in the study. All patients underwent similar antenatal care, which included ultrasound examinations at 11-14, 19-22 and 33-35 weeks. Ultrasound findings of placental and/or umbilical cord abnormalities were recorded using the same protocol for both groups and confirmed after birth. RESULTS: IVF pregnancies had a significantly higher risk of low-lying placenta, placenta previa, bilobed placenta and velamentous cord insertion (VCI) compared with spontaneous pregnancies. In the heterologous subgroup there was a significant increased incidence of placenta accreta spectrum (PAS) disorders than in spontaneous pregnancies. All these anomalies were identified prenatally on ultrasound imaging and confirmed at birth. DISCUSSION: IVF pregnancies in general and those resulting from donor oocyte in particular are at higher risk of placental and umbilical cord abnormalities compared to spontaneous pregnancies. These anomalies can be diagnosed accurately at the mid-trimester detailed fetal anomaly scan and our findings support the need for a targeted ultrasound screening of these anomalies in IVF pregnancies.

Prenatal diagnosis and outcome of fetal posterior fossa fluid collections.

OBJECTIVE: To evaluate the accuracy of fetal imaging in differentiating between diagnoses involving posterior fossa fluid collections and to investigate the postnatal outcome of affected infants. METHODS: This was a retrospective study of fetuses with posterior fossa fluid collections, carried out between 2001 and 2010 in two referral centers for prenatal diagnosis. All fetuses underwent multiplanar neurosonography. Parents were also offered fetal magnetic resonance imaging (MRI) and karyotyping. Prenatal diagnosis was compared with autopsy or postnatal MRI findings and detailed follow-up was attempted by consultation of medical records and interview with parents and pediatricians. RESULTS: During the study period, 105 fetuses were examined, at a mean gestational age of 24 (range, 17-28) weeks. Sonographic diagnoses (Blake's pouch cyst, n = 32; megacisterna magna, n = 27; Dandy-Walker malformation, n = 26; vermian hypoplasia, n = 17; cerebellar hypoplasia, n = 2; arachnoid cyst, n = 1) were accurate in 88% of the 65 cases in which confirmation was possible. MRI proved more informative than ultrasound in only 1/51 cases. Anatomic anomalies and/or chromosomal aberrations were found in 43% of cases. Blake's pouch cysts and megacisterna magna underwent spontaneous resolution in utero in one third of cases and over 90% of survivors without associated anomalies had normal developmental outcome at 1-5 years. Isolated Dandy-Walker malformation and vermian hypoplasia were associated with normal developmental outcome in only 50% of cases. CONCLUSION: Prenatal neurosonography and MRI are similarly accurate in the categorization of posterior fossa fluid collections from mid gestation. Blake's pouch cyst and megacisterna magna are risk factors for associated anomalies but when isolated have an excellent prognosis, with a high probability of intrauterine resolution and normal intellectual development in almost all cases. Conversely, Dandy-Walker malformation and vermian hypoplasia, even when they appear isolated antenatally, are associated with an abnormal outcome in half of cases.

Brainstem-vermis and brainstem-tentorium angles allow accurate categorization of fetal upward rotation of cerebellar vermis.

OBJECTIVE: To evaluate the role of the brainstem-vermis (BV) and brainstem-tentorium (BT) angles in the differential diagnosis of upward rotation of the fetal cerebellar vermis. METHODS: The BV and BT angles were measured retrospectively on median sonographic views of the brain in 31 fetuses at 19-28 weeks' gestation with upward rotation of the cerebellar vermis due to Blake's pouch cyst (n = 12), Dandy-Walker malformation (n = 12) and cerebellar vermian hypoplasia (n = 7). Eighty normal fetuses at 20-24 weeks were included as controls. RESULTS: In the control group, BV and BT angles were 9.1 ± 3.5° (range, 4-17°) and 29.3 ± 5.8° (range, 21-44°), respectively. The BV angle was significantly increased in each of the three subgroups of anomalies: Blake's pouch cyst (23 ± 2.8°; range, 19-26°), vermian hypoplasia (34.9 ± 5.4°; range, 24-40°) and Dandy-Walker malformation (63.5 ± 17.6°; range, 45-112°), the angle increasing with increasing severity of the condition. The BT angle had a similar pattern but there was overlap among the different groups. CONCLUSION: The BV angle and, to a lesser degree, the BT angle are simple and reproducible measurements that provide valuable additional information for the categorization of upward rotation of the fetal cerebellar vermis. From mid gestation, a BV angle > 45° is strongly suggestive of a Dandy-Walker malformation, while a measurement < 30° favors the diagnosis of a Blake's pouch cyst.

The effect of the contents of exomphalos and nuchal translucency at 11-14 weeks on the likelihood of associated chromosomal abnormality.

OBJECTIVES: Previous publications suggest that exomphalos containing the liver as less likely to be associated with aneuploidy. The objective of the study was to explore the influence of exomphalos contents and nuchal translucency (NT) on the likelihood of aneuploidy. METHODS: A retrospective search was conducted to identify all cases of exomphalos from the databases of two fetal medicine units seen from September 2000 to March 2011. RESULTS: A total of 95 fetuses with exomphalos were selected. NT was normal in 42 fetuses (44.2%). The exomphalos content was bowel alone in 68 (71.6%). The effect of exomphalos content and NT on likelihood of aneuploidy was explored using logistic regression. It showed no significant contribution of exomphalos content on the likelihood of aneuploidy (adjusted odds ratio: 1.44, 95% CI: 0.538 to 3.84). CONCLUSIONS: When the diagnosis is made in the first trimester, the risk of aneuploidy is no different when the sac contains only bowel as compared with when it contains the liver. Increase in the NT is 4-5 times as likely with an abnormal karyotype as with normal NT. Detection of exomphalos in the first trimester warrants an offer of chromosomal assessment regardless of sac contents or NT.

Maternal cardiac function in normal twin pregnancy: a longitudinal study.

OBJECTIVE: To investigate maternal cardiac function in a cohort of uncomplicated twin gestations assessed longitudinally. METHODS: Women with twin pregnancies were enrolled prospectively and underwent serial maternal echocardiography at 20-23 weeks, 26-29 weeks and 30-33 weeks of gestation. Patients were excluded if any of these complications occurred after recruitment: delivery < 34 weeks; pre-eclampsia or gestational hypertension; small-for-gestational age neonates (birth weight of one or both twins < 5(th) centile for gestational age). Cardiac findings were compared with those obtained at the same gestational age periods in a group of singleton gestations. RESULTS: A group of 20 uncomplicated twin gestations was obtained for analysis and 10 singleton pregnancies were then selected as controls. At each visit, mean ± SD cardiac output (CO) was significantly higher in twins than in singletons (6.55 ± 0.82 vs 5.62 ± 0.82 L/min, P = 0.007 at 20-23 weeks; 7.31 ± 0.74 vs 6.39 ± 0.74 L/min, P = 0.003 at 26-29 weeks; 7.50 ± 0.89 vs 6.68 ± 0.65 L/min, P = 0.015 at 30-33 weeks), whereas total vascular resistance (TVR) was lower (1005 ± 137 vs 1179 ± 199 dynes × s/cm(5) , P = 0.009 at 20-23 weeks; 924 ± 100 vs 1070 ± 138 dynes × s/cm(5), P = 0.003 at 26-29 weeks; 929 ± 96 vs 1031 ± 122 dynes × s/cm(5), P = 0.018 at 30-33 weeks). In both twins and singletons, CO showed a significant increase while TVR decreased significantly throughout the assessed pregnancy time period. CONCLUSION: In twin gestation, maternal cardiac function apparently undergoes more profound changes compared with in singleton gestation, as testified by higher CO and lower TVR values at each stage of pregnancy starting from the mid-trimester.

Increased uterine artery pulsatility index at 34 weeks and outcome of pregnancy.

OBJECTIVES: To evaluate pregnancy outcome in patients with increased uterine artery (UtA) pulsatility at 34 weeks' gestation as an isolated finding. METHODS: Normotensive women attending at 34 weeks' gestation for fetal growth assessment were enrolled in the study if fetal growth was appropriate for age and mean UtA pulsatility index (PI) was persistently above the 95(th) centile for gestational age. Patients were excluded with any of the following conditions: multiple pregnancy, sonographic suspicion of fetal anomaly or fetal growth restriction, history of chronic maternal disease, hypertensive disorder or diabetes in the current pregnancy or one or more adverse events in their past obstetric history. The control group consisted of age- and body mass index-matched low-risk women attending at 34 weeks with normal uterine artery Doppler since the midtrimester. RESULTS: Sixty-six normotensive patients with normal fetal growth and increased UtA-PI at 34 weeks were included in the study group. Women with abnormal Doppler findings compared with controls showed significantly lower gestational age at delivery (38.2 ± 1.6 vs. 38.9 ± 1.3 weeks, P = 0.006), birth weight (2942 ± 583 vs. 3404 ± 469 g, P < 0.001), birth-weight Z-score (-0.61 ± 1.07 vs. 0.19 ± 1.05, P < 0.001) and increased risk of a small-for-gestational-age (SGA) newborn (13/66 vs. 1/66, P < 0.001). The occurrence of late pre-eclampsia (3/66 vs. 0/66, P = 0.24), admission to the neonatal intensive care unit (6/66 vs. 4/66, P = 0.74), rate of induction of labor (16/66 vs. 14/66, P = 0.83) and rate of Cesarean section due to fetal distress (6/66 vs. 3/66, P = 0.49) were comparable between the two groups. CONCLUSION: Increased UtA-PI as an isolated finding at 34 weeks' gestation is associated with an increased risk of delivering an SGA neonate.

Accuracy of fetal gender determination in the first trimester using three-dimensional ultrasound.

OBJECTIVES: To evaluate the accuracy of three-dimensional (3D) ultrasound in fetal gender assignment in the first trimester. METHODS: A series of pregnant women attending at 11 to 13 + 6 weeks for the nuchal translucency (NT) scan were enrolled into the study. An ultrasound volume of each fetus was obtained and stored for offline analysis. On the reconstructed mid-sagittal plane, the angle between the genital tubercle and an imaginary line passing tangentially through the fetal back (genital angle) was estimated and a receiver-operating characteristics (ROC) curve was constructed to determine the best cut-off for genital angle in fetal male gender determination. Fetal gender was subsequently ascertained in all cases. To calculate the interobserver variability, a second operator repeated the measurements. RESULTS: There were 85 cases included in the study. The genital angle in males was significantly higher than that in females (51.2 ± 11.3° (n = 36) vs. 18.9 ± 4.1 (n = 49), P < 0.001). The ROC curve revealed the estimated genital angle to have a high degree of accuracy in fetal gender determination (area under the curve ± SE = 1.000 ± 0.001). The best cut-off for male gender determination was found to be between 27° and 29° (sensitivity, 100%; specificity, 98.0%). There was a high degree of correlation between the two operators (r(2) = 0.998; coefficient of variation = 5.4%). CONCLUSIONS: 3D ultrasound is a highly accurate and reproducible tool for fetal gender assignment prior to 14 weeks of gestation.

Three-dimensional ultrasound in monitoring progression of labor: a reproducibility study.

OBJECTIVE: The aim of this study was to evaluate the intraobserver and interobserver reproducibility of measurements, obtained from stored ultrasound volumes, related to fetal head progression in the birth canal. METHODS: From January to September 2009, serial ultrasound volumes were obtained from women in labor, stored and separately evaluated by two different operators using the SonoVCAD™ labor software. Volumes were aligned using the pubic bone and the urethra as references. In the sagittal plane of the pelvis, the following data were calculated: head progression distance (the distance between the infrapubic line and the lowest part of the fetal skull), head direction (the angle between the infrapubic line and the major longitudinal axis of the fetal head) and head progression angle (the angle between the longitudinal axis of the pubic bone and a line joining the lowest edge of the pubis to the lowest convexity of the fetal skull). In the transverse plane, the angle formed by the midline with the anteroposterior axis of the maternal pelvis (midline angle) was also measured. For each measurement, intraobserver and interobserver reproducibility was determined. RESULTS: We analyzed 30 ultrasound volumes. For all parameters, interobserver variation was significantly higher than intraobserver variation. Reproducibility was good for all parameters, except for the midline angle. Among the different ultrasound measurements, the progression angle presented the highest reproducibility. CONCLUSIONS: Measurements obtained from stored ultrasound volumes to assess fetal head progression in the second stage of labor have good reproducibility, with progression distance and progression angle being the most reproducible parameters.

Persistence of increased uterine artery resistance in the third trimester and pregnancy outcome.

OBJECTIVE: To evaluate whether the persistence of abnormal findings in the third trimester following increased uterine artery (UtA) resistance in the second trimester is related to adverse pregnancy outcome. METHODS: Low-risk nulliparous women with increased UtA mean pulsatility index (PI) at 20-22 weeks underwent repeat Doppler interrogation at 26-28 weeks and were divided into two groups: those with persistently abnormal Doppler and those with normalized UtA findings. Pregnancy outcome was noted for all patients and compared with that of 104 controls. RESULTS: We examined 104 women with increased UtA resistance in the second trimester and in 62 (59.6%) cases the abnormal uteroplacental Doppler findings persisted to 26-28 weeks. Compared with controls and with patients with normalized Doppler at the third-trimester scan, patients with persistently abnormal Doppler results had a significantly higher risk of pre-eclampsia (10/62 vs. 1/104, P = 0.002 and 10/62 vs. 1/42, P = 0.047, respectively), small-for-gestational age (SGA) fetus (20/62 vs. 1/104, P < 0.001 and 20/62 vs. 4/42; P = 0.007, respectively) and admission of the infant to a neonatal intensive care unit (16/62 vs. 4/104; P < 0.001 and 16/62 vs. 1/42; P < 0.001, respectively). Compared with controls, cases with normalization had an increased risk of SGA (4/42 vs. 1/104, P = 0.03), but there were no significant differences for the other outcome measures. CONCLUSIONS: In low-risk nulliparous women with increased UtA resistance in the second trimester, the persistence of abnormal Doppler findings at 26-28 weeks is associated with an increased risk of obstetric complications when compared with both controls and patients with third-trimester Doppler normalization.

Prenatal ultrasound in the prediction of bowel obstruction in infants with gastroschisis.

OBJECTIVE: To assess the value of prenatal ultrasound in predicting bowel obstruction requiring surgery in fetuses with prenatal diagnosis of gastroschisis. METHODS: The database of our center was searched for cases with an antenatal diagnosis of gastroschisis. The ultrasound images were reviewed blindly to assess the presence of intra- or extra-abdominal bowel dilatation. Details of surgical procedures were noted and the discharge letters were obtained. Pediatric follow-up was also obtained from pediatric surgeons, general practitioners or parents. RESULTS: In the 10-year period between November 1998 and September 2008 there were 62 cases with a prenatal diagnosis of gastroschisis. Postnatal outcome was not available for five cases, four pregnancies underwent termination and intrauterine fetal demise occurred in five cases. A final population of 48 liveborn infants was available for analysis. Intra-abdominal bowel dilatation was identified in 14 of these 48 fetuses (29.2%) and extra-abdominal bowel dilatation in 30 (62.5%) fetuses on prenatal ultrasound images. Eight fetuses (16.7%) had bowel obstruction. The relative risk of bowel obstruction with intra-abdominal bowel dilatation was 4.05 (95% CI, 1.12-14.70). On the other hand, the relative risk of bowel obstruction with extra-abdominal bowel dilatation was 1.0 (95% CI, 0.37-3.70). Four babies died, two of whom had intra- and one had extra-abdominal bowel dilatation. CONCLUSIONS: Intra-abdominal dilatation of the bowel on prenatal ultrasound examination appears to predict postnatal bowel obstruction and the need for surgical resection. Extra-abdominal bowel dilatation is observed frequently on prenatal ultrasound scans, but is not predictive of bowel obstruction.

Prenatal diagnosis and outcome of partial agenesis and hypoplasia of the corpus callosum.

OBJECTIVE: To present antenatal sonographic findings and outcome of fetuses with hypoplasia or partial agenesis of the corpus callosum. METHODS: The database of our ultrasound laboratory was searched retrospectively for cases of hypoplasia or partial agenesis of the corpus callosum suspected at antenatal neurosonography between 1998 and 2008 and confirmed by pathology or postnatal neuroimaging. In surviving infants, clinical follow-up had been arranged to assess neurodevelopmental outcome. RESULTS: Nineteen fetuses with callosal underdevelopment were identified at a median gestational age of 22 (range, 21-33) weeks and confirmed at follow-up, including 14 with partial agenesis and five with hypoplasia. Among the 14 fetuses with partial agenesis, there were additional brain findings in 10, including two with absent cavum septi pellucidi, four with mild isolated ventriculomegaly and four with cerebellar abnormalities, two of which also had ventriculomegaly. Pregnancy was terminated electively in seven of the cases with partial agenesis and there was one neonatal death. Among the six surviving infants, neurodevelopmental outcome was appropriate for age in three at follow up, including two cases with isolated partial agenesis of the corpus callosum. Among the five fetuses with prenatally diagnosed callosal hypoplasia, additional anomalies were present in four. Two cases were terminated electively and three were alive at the time of writing, with a median age of 3 years. Among them, apparently normal neurological development was observed in only one case. CONCLUSIONS: An antenatal diagnosis of callosal underdevelopment is possible by expert sonography. There is often association with other major anomalies. However, even in fetuses with apparently isolated findings, the prognosis is uncertain.

Cervical length and risk of antepartum bleeding in women with complete placenta previa.

OBJECTIVE: To evaluate if cervical length predicts prepartum bleeding and emergency Cesarean section in cases of placenta previa. METHODS: Between September 2005 and September 2007, cervical length was measured by transvaginal ultrasound in women with complete placenta previa persisting into the third trimester of pregnancy. A complete follow-up of pregnancy was obtained in all cases. RESULTS: Overall, 59 women were included in the study group. The mean +/- SD gestational age at ultrasound was 30.7 +/- 2.7 weeks and the cervical length was 36.9 +/- 8.8 mm. Cesarean delivery was performed in all cases, at a mean gestational age of 34.7 +/- 2.3 weeks. Twenty-nine (49.1%) of the women presented prepartum bleeding and 12 (20.3%) required an emergency Cesarean section prior to 34 completed weeks due to massive hemorrhage. Cervical length did not differ significantly between cases with and those without prepartum bleeding (35.3 +/- 9.3 mm vs. 38.4 +/- 8.2 mm; P = 0.18), but was significantly shorter among patients who underwent emergency Cesarean section < 34 weeks due to massive hemorrhage compared with patients who underwent elective Cesarean section (29.4 +/- 5.7 mm vs. 38.8 +/- 8.5 mm; P = 0.0006). CONCLUSIONS: Transvaginal sonographic cervical length predicts the risk of emergency Cesarean section < 34 weeks in women with complete placenta previa.

Variability of Forebrain Commissures in Callosal Agenesis: A Prenatal MR Imaging Study.

BACKGROUND AND PURPOSE: Agenesis of the corpus callosum, even when isolated, may be characterized by anatomic variability. The aim of this study was to describe the types of other forebrain commissures in a large cohort of randomly enrolled fetuses with apparently isolated agenesis of the corpus callosum at prenatal MR imaging. MATERIALS AND METHODS: All fetuses with apparent isolated agenesis of the corpus callosum undergoing prenatal MR imaging from 2004 to 2014, were evaluated for the presence of the anterior or a vestigial hippocampal commissure assessed in consensus by 2 pediatric neuroradiologists. RESULTS: Overall, 62 cases of agenesis of the corpus callosum were retrieved from our data base. In 3/62 fetuses (4.8%), no forebrain commissure was visible at prenatal MR imaging, 23/62 fetuses (37.1%) presented with only the anterior commissure, and 20/62 fetuses (32.3%) showed both the anterior commissure and a residual vestigial hippocampal commissure, whereas in the remaining 16/62 fetuses (25.8%), a hybrid structure merging a residual vestigial hippocampal commissure and a rudiment of the corpus callosum body was detectable. Postnatal MR imaging, when available, confirmed prenatal forebrain commissure findings. CONCLUSIONS: Most fetuses with apparent isolated agenesis of the corpus callosum showed at least 1 forebrain commissure at prenatal MR imaging, and approximately half of fetuses also had a second commissure: a vestigial hippocampal commissure or a hybrid made of a hippocampal commissure and a rudimentary corpus callosum body. Whether such variability is the result of different genotypes and whether it may have any impact on the long-term neurodevelopmental outcome remains to be assessed.