Fetal Anomaly Scan Research Articles

The impact of cut-off values on the prevalence of short cervical length in pregnancy

BackgroundA prior study suggested that implementing a cut-off value of ≤30 mm for a short cervical length (CL) could potentially introduce selection bias and alter the distribution of CL measurements. As such, the objective of this study is to evaluate how CL distribution and incidence of short CL are affected when using different cut-off values for a short CL. Study designThis is a secondary analysis of the Quadruple P (QP) Screening study; a prospective cohort study that included low-risk patients with singleton pregnancies undergoing fetal anomaly scan at 18–22 weeks of gestation, including a CL measurement. Patients with a short cervix, defined as ≤35 mm, were subsequently counseled for the QP trial; a randomized controlled trial (RCT) comparing progesterone to cervical pessary for the prevention of preterm birth. If participation to the RCT was refused, patients with a CL ≤25 mm were advised to use progestogen. The primary objective of this current study was to assess the normal distribution of CL across the entire cohort and to assess the incidence of short CL when using the cut-off values of ≤35 and ≤25 mm. Normal distributions for CL were simulated based on mean and standard deviation(SD) of the original data. The Kolmogorov-Smirnov test was used to evaluate the distribution of the CL measurements. Moreover, to evaluate the motives behind ultrasound measurements around the cut-off value, sonographers were asked to fill out a qualitative questionnaire. ResultsThe total cohort included 19.171 eligible participants who underwent CL measurement, with a mean CL of 43.9 mm (±8.1 SD). The distribution of all CL observed measurements deviated significantly from the normal distribution (p < 0.001). A total of 1.852 (9.7%) patients had short CL ≤35 mm, which was significantly lower than expected when compared to the simulated normal distribution (n = 2.661, 13.9%; p < 0.001). The incidence of short CL ≤25 mm in our cohort statistically differed from the simulated normal distribution (238, 1.2% vs 177, 0.9%; p=0.003). When comparing our data to the simulated normal distribution, the difference in distributions is most pronounced when examining the difference between 35 and 36 mm. Results of the questionnaire reveal sonographers claimed not to be influenced by a cut-off value for study participation or progesterone treatment. ConclusionThis study demonstrates that using any cut-off value for a short CL influences the incidence and distribution of CL. When using a cut-off value of ≤35 mm for study inclusion, the incidence of measurements of a short CL is lower than the anticipated incidence compared to a normal distribution. However, when using a cut-off value of ≤25 mm for progesterone treatment, the frequency of CL measurements is higher than expected below this threshold compared to a normal distribution. This study highlights the risk of introducing selection bias, most likely unintentionally, when cut-off values for short CL are used, regardless of the specific value chosen. Therefore healthcare providers should measure the CL with caution if essential decisions depend on a specific cut-off value.

Determination of the Normative Value of Fetal Left Brachiocephalic Vein Diameter Using Ultrasound in a Tertiary Care Hospital in Eastern India.

Fetal ultrasound plays a vital role in prenatal care by offering key insights into fetal growth and facilitating the early identification of congenital abnormalities. Among various anatomical structures, the fetal left brachiocephalic vein (FLBCV) plays a significant role in fetal circulation, yet normative data for FLBCV dimensions are limited, particularly in diverse populations. This study aims to establish normative values for FLBCV diameter in fetuses between 18 and 23 weeks of gestation in a tertiary care hospital in Eastern India. Such data are essential for accurate clinical assessment and early diagnosis of potential congenital anomalies. This descriptive study was conducted at the College of Medicine and Sagore Dutta Hospital, Kolkata, India, from January to December 2022. The study included 287 singleton pregnancies between 18 and 23 weeks of gestation, excluding cases with maternal or fetal conditions that could affect the measurements. LBCV diameter was measured using transabdominal ultrasound, and the normative values were established using percentile charts. Correlation analyses were performed to assess the relationship between FLBCV diameter and various fetal and maternal parameters. Linear regression analysis was done to identify significant predictors of FLBCV diameter. FLBCV diameter showed a consistent increase with gestational age, ranging from a median of 1.87 mm at 18 completed weeks to 2.27 mm at 22 completed weeks. The 95th percentile values exhibited more pronounced growth, particularly between 18 and 20 weeks. Significant positive correlations were observed between FLBCV diameter and fetal biometric parameters such as biparietal diameter, head circumference, abdominal circumference, and femur length. Head circumference emerged as the most significant predictor (p=0.007) of FLBCV diameter in the linear regression model. This study provides essential normative data on FLBCV diameter for the Indian population, offering a valuable reference for clinicians in prenatal diagnostics. The incorporation of FLBCV measurement in basic fetal echocardiography, which is a part of the second-trimester fetal anomaly scan, could enhance the detection of congenital anomalies, contributing to improved prenatal care.

Comparing transabdominal and transvaginal cervical length measurements at mid‐trimester fetal anomaly scan: The impact of bladder fullness and lower uterine contractions

Comparing transabdominal and transvaginal cervical length measurements at mid‐trimester fetal anomaly scan: The impact of bladder fullness and lower uterine contractions

Probe motion during mid-trimester fetal anomaly scan in the clinical setting: A prospective observational study

IntroductionThis study aims to investigate probe motion during full mid-trimester anomaly scans. MethodsWe undertook a prospective, observational study of obstetric sonographers at a UK University Teaching Hospital. We collected prospectively full-length video recordings of routine second-trimester anomaly scans synchronized with probe trajectory tracking data during the scan. Videos were reviewed and trajectories analyzed using duration, path metrics (path length, velocity, acceleration, jerk, and volume) and angular metrics (spectral arc, angular area, angular velocity, angular acceleration, and angular jerk). These trajectories were then compared according to the participant level of expertise, fetal presentation, and patient BMI. ResultsA total of 17 anomaly scans were recorded. The average velocity of the probe was 12.9 ± 3.4 mm/s for the consultants versus 24.6 ± 5.7 mm/s for the fellows (p = 0.02), the average acceleration 170.4 ± 26.3 mm/s2 versus 328.9 ± 62.7 mm/s2 (p = 0.02), and the average jerk 7491.7 ± 1056.1 mm/s3 versus 14944.1 ± 3146.3 mm/s3 (p = 0.02), the working volume 9.106 ± 4.106 mm3 versus 29.106 ± 11.106 mm3 (p = 0.03), respectively. The angular metrics were not significantly different according to the participant level of expertise, the fetal presentation, or to patients BMI. ConclusionSome differences in the probe path metrics (velocity, acceleration, jerk and working volume) were noticed according to operator’s level.

Diagnostic accuracy of ultrasound screening for fetal structural abnormalities during the first and second trimester of pregnancy in low-risk and unselected populations.

Prenatal ultrasound is widely used to screen for structural anomalies before birth. While this is traditionally done in the second trimester, there is an increasing use of first-trimester ultrasound for early detection of lethal and certain severe structural anomalies. To evaluate the diagnostic accuracy of ultrasound in detecting fetal structural anomalies before 14 and 24 weeks' gestation in low-risk and unselected pregnant women and to compare the current two main prenatal screening approaches: a single second-trimester scan (single-stage screening) and a first- and second-trimester scan combined (two-stage screening) in terms of anomaly detection before 24 weeks' gestation. We searched MEDLINE, EMBASE, Science Citation Index Expanded (Web of Science), Social Sciences Citation Index (Web of Science), Arts & Humanities Citation Index and Emerging Sources Citation Index (Web of Science) from 1 January 1997 to 22 July 2022. We limited our search to studies published after 1997 and excluded animal studies, reviews and case reports. No further restrictions were applied. We also screened reference lists and citing articles of each of the included studies. Studies were eligible if they included low-risk or unselected pregnant women undergoing a first- and/or second-trimester fetal anomaly scan, conducted at 11 to 14 or 18 to 24 weeks' gestation, respectively. The reference standard was detection of anomalies at birth or postmortem. Two review authors independently undertook study selection, quality assessment (QUADAS-2), data extraction and evaluation of the certainty of evidence (GRADE approach). We used univariate random-effects logistic regression models for the meta-analysis of sensitivity and specificity. Eighty-seven studies covering 7,057,859 fetuses (including 25,202 with structural anomalies) were included. No study was deemed low risk across all QUADAS-2 domains. Main methodological concerns included risk of bias in the reference standard domain and risk of partial verification. Applicability concerns were common in studies evaluating first-trimester scans and two-stage screening in terms of patient selection due to frequent recruitment from single tertiary centres without exclusion of referrals. We reported ultrasound accuracy for fetal structural anomalies overall, by severity, affected organ system and for 46 specific anomalies. Detection rates varied widely across categories, with the highest estimates of sensitivity for thoracic and abdominal wall anomalies and the lowest for gastrointestinal anomalies across all tests. The summary sensitivity of a first-trimester scan was 37.5% for detection of structural anomalies overall (95% confidence interval (CI) 31.1 to 44.3; low-certainty evidence) and 91.3% for lethal anomalies (95% CI 83.9 to 95.5; moderate-certainty evidence), with an overall specificity of 99.9% (95% CI 99.9 to 100; low-certainty evidence). Two-stage screening had a combined sensitivity of 83.8% (95% CI 74.7 to 90.1; low-certainty evidence), while single-stage screening had a sensitivity of 50.5% (95% CI 38.5 to 62.4; very low-certainty evidence). The specificity of two-stage screening was 99.9% (95% CI 99.7 to 100; low-certainty evidence) and for single-stage screening, it was 99.8% (95% CI 99.2 to 100; moderate-certainty evidence). Indirect comparisons suggested superiority of two-stage screening across all analyses regarding sensitivity, with no significant difference in specificity. However, the certainty of the evidence is very low due to the absence of direct comparisons. A first-trimester scan has the potential to detect lethal and certain severe anomalies with high accuracy before 14 weeks' gestation, despite its limited overall sensitivity. Conversely, two-stage screening shows high accuracy in detecting most fetal structural anomalies before 24 weeks' gestation with high sensitivity and specificity. In a hypothetical cohort of 100,000 fetuses, the first-trimester scan is expected to correctly identify 113 out of 124 fetuses with lethal anomalies (91.3%) and 665 out of 1776 fetuses with any anomaly (37.5%). However, 79 false-positive diagnoses are anticipated among 98,224 fetuses (0.08%). Two-stage screening is expected to correctly identify 1448 out of 1776 cases of structural anomalies overall (83.8%), with 118 false positives (0.1%). In contrast, single-stage screening is expected to correctly identify 896 out of 1776 cases before 24 weeks' gestation (50.5%), with 205 false-positive diagnoses (0.2%). This represents a difference of 592 fewer correct identifications and 88 more false positives compared to two-stage screening. However, it is crucial to acknowledge the uncertainty surrounding the additional benefits of two-stage versus single-stage screening, as there are no studies directly comparing them. Moreover, the evidence supporting the accuracy of first-trimester ultrasound and two-stage screening approaches primarily originates from studies conducted in single tertiary care facilities, which restricts the generalisability of the results of this meta-analysis to the broader population.

Fetal premature atrial contractions: natural course, risk factors and adverse outcome.

Fetal premature atrial contractions (PAC) are usually benign but may be associated with congenital heart defect (CHD) and tachyarrhythmia, which in turn carry a risk of cardiac failure and fetal death. We aimed to explore the frequency of adverse outcome and to identify risk factors for tachyarrhythmia in pregnancies complicated by fetal PAC. This was a retrospective cohort study of fetuses diagnosed with PAC at two academic centers in Amsterdam, The Netherlands, between 2007 and 2022. Cases with a congenital anomaly and those with a prior diagnosis of CHD or other arrhythmias were excluded. M-mode and Doppler tracings were reanalyzed and the frequency of PAC was recorded. The incidence of the following adverse outcomes was examined: underlying CHD not identified at the 20-week fetal anomaly scan, tachyarrhythmia, other arrhythmia, administration of antiarrhythmic therapy and death. Risk factors for tachyarrhythmia were analyzed using odds ratios (OR). In 24.1% of 1439 referred cases, PAC resolved before confirmation at the fetal medicine unit (FMU). Of the 939 included cases with confirmed PAC, the total incidence of adverse outcome was 6.8% (64/939). CHD was diagnosed in 14 (1.5% (95% CI, 0.9-2.5%)) cases, of which eight were diagnosed prenatally and six postnatally. Compared with baseline, the incidence of CHD was higher in the presence of fetal PAC (OR, 1.8 (95% CI, 1.0-3.3); P = 0.034). Tachyarrhythmia occurred prenatally and/or postnatally in 32 (3.4%) cases, of which eight (25.0%) showed signs of cardiac failure, and in 23 (71.9%) cases, antiarrhythmic therapy was required. No cases of tachyarrhythmia led to fetal or infant death. Risk factors for tachyarrhythmia were PAC with short runs of supraventricular tachycardia (OR, 98.7), blocked PAC (OR, 30.3), PAC in bigeminy (OR, 21.8), frequent PAC (one per 5-10 beats) (OR, 6.9), signs of cardiac failure (OR, 14.2) and the presence of a foramen ovale aneurysm (OR, 5.0). PAC are generally benign and often resolve spontaneously. However, fetuses with an irregular heart rhythm should be referred for advanced ultrasonography, which should focus on classifying the type of PAC and risk of adverse outcome. When risk factors for tachyarrhythmia are identified, weekly fetal heart-rate monitoring is advised until resolution of the PAC. In the absence of risk factors, standard obstetric care may be sufficient, with additional instructions to report reduced fetal movements. Should tachyarrhythmia or cardiac failure develop, referral back to the FMU is indicated. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Incorporation of vasa previa screening into a routine anomaly scan: A single center cohort study.

Vasa previa (VP), defined as unprotected fetal vessels traversing the membranes over the cervix, is associated with a high perinatal mortality when undiagnosed prenatally. Conversely, prenatal diagnosis with ultrasound and cesarean delivery before the membranes rupture is associated with excellent outcomes. However, controversy exists regarding screening for VP. In the UK, routine screening for VP is not recommended. The objective of this study was to report the incidence of VP and our experience in the detection of VP with a universal screening protocol at the time of the second-trimester fetal anomaly scan with third-trimester confirmation in an unselected population of pregnancies. We performed a single-center historical cohort study of all pregnant women who underwent routine second-trimester anomaly screening scans at West Middlesex University Hospital, London, UK, between 2012 and 2016. Over 5 years, every patient undergoing routine anomaly screening was evaluated for VP using a systematic protocol during their 20-week anomaly scan. Suspected cases of VP were rescanned in the third trimester by specialist sonographers with an interest in VP. The primary outcomes were the incidence and detection of VP. During the study period, 24 690 anatomy scans were performed. A total of 64 patients were identified as having potential VP at the second-trimester anomaly screening scan, of which 19 were confirmed by the specialist sonographer in the third trimester and at delivery. The screen positive rate was 0.26% (95% confidence interval [CI] 0.20%-0.32%). VP at birth was found in 19/24690 births (1:1299 [95% CI: 1:832-1:2030] births). Universal screening for VP using our protocol had a sensitivity of 100% and a specificity of 99.78% (95% CI: 99.72%-99.84%). The false-positive rate of the second-trimester screen was 0.18% (95% CI: 0.13-0.24). There were no false positives or false negatives at delivery. Of the 19 patients with confirmed VP, 17 had scheduled cesarean deliveries, and two required emergency deliveries due to antepartum hemorrhage. One baby died, giving a perinatal mortality of 5%. VP complicates approximately 1:1300 pregnancies. Routine screening for VP yielded a 100% detection rate. We suggest the inclusion of structured VP assessment in standard fetal anomaly screening programs.

Polyhydramnios associated with rare genetic syndromes: two case reports

BackgroundWe present two genetic causes of polyhydramnios that were challenging to diagnose due to their rarity and complexity. In view of the severe implications, we wish to highlight these rare genetic conditions when obstetricians consider differential diagnoses of polyhydramnios in the third trimester.Case presentationPatient 1 is a 34-year-old Asian woman who was diagnosed with polyhydramnios at 28 weeks’ gestation. First trimester testing, fetal anomaly scan, and intrauterine infection screen were normal. Subsequent antenatal ultrasound scans revealed macroglossia, raising the suspicion for Beckwith–Wiedemann syndrome. Chromosomal microarray analysis revealed a female profile with no pathological copy number variants. The patient underwent amnioreduction twice in the pregnancy. The patient presented in preterm labor at 34 weeks’ gestation but elected for an emergency caesarean section. Postnatally, the baby was noted to have a bell-shaped thorax, coat hanger ribs, hypotonia, abdominal distension, and facial dysmorphisms suggestive of Kagami–Ogata syndrome. Patient 2 is a 30-year-old Asian woman who was diagnosed with polyhydramnios at 30 weeks’ gestation. She had a high-risk first trimester screen but declined invasive testing; non-invasive prenatal testing was low risk. Ultrasound examination revealed a macrosomic fetus with grade 1 echogenic bowels but no other abnormalities. Intrauterine infection screen was negative, and there was no sonographic evidence of fetal anemia. She had spontaneous rupture of membranes at 37 + 3 weeks but subsequently delivered by caesarean section in view of pathological cardiotocography. The baby was noted to have inspiratory stridor, hypotonia, low-set ears, and bilateral toe polysyndactyly. Further genetic testing revealed a female profile with a pathogenic variant of the GLI3 gene, confirming a diagnosis of Greig cephalopolysyndactyly syndrome.ConclusionThese cases illustrate the importance of considering rare genetic causes of polyhydramnios in the differential diagnosis, particularly when fetal anomalies are not apparent at the 20-week structural scan. We would like to raise awareness for these rare conditions, as a high index of suspicion enables appropriate counseling, prenatal testing, and timely referral to pediatricians and geneticists. Early identification and diagnosis allow planning of perinatal care and birth in a tertiary center managed by a multidisciplinary team.

Routine Echocardiography is not Required in Neonates with Arterial Ischemic Stroke.

Current guidelines suggest routine echocardiography (ECHO) in the acute phase to exclude a cardiac source for neonatal arterial ischemic stroke (NAIS). However, the commonly assumed embolic origin from a cardiac source for NAIS is challenged and the need for ECHO in NAIS remains questionable, especially during the era of standard fetal anomaly scanning. Our hypothesis is that any complex cardiac defects potentially causing NAIS would likely be detected during routine prenatal scans, thus possibly making routine postnatal ECHO redundant. This study aimed to determine the prevalence of significant cardiac risk factors and evaluate the necessity of routine postnatal ECHO in NAIS during the routine use of prenatal fetal sonography. Retrospective review of 54 infants diagnosed with NAIS via brain magnetic resonance imaging who underwent an ECHO evaluation during the acute period to exclude potential cardiac origins for NAIS. Postnatal ECHO revealed no intracardiac thrombus or vegetation, and only identified structural heart anomalies in three (5%) infants. Interestingly, these three cases had already been diagnosed with syndromic conditions or chromosomal malformations prenatally. In the remaining infants, postnatal ECHO was either normal or showed minor abnormalities unlikely to have contributed to the stroke. The detection rates of complex cardiac anomalies from prenatal scans and postnatal ECHO were statistically similar (p = 0.617). The probability of ECHO to exclude cardiac sources for NAIS is so low that in the era of standard fetal anomaly scanning, routine postnatal ECHO may not be necessary for all NAIS infants, except when chromosomal malformations are detected. · Guidelines recommend an acute phase ECHO to identify a cardiac source of NAIS.. · ECHO not effective at excluding NAIS's cardiac origin for infants with normal fetal scans.. · Routine postnatal ECHO is unnecessary in NAIS infants, except with genetic abnormalities..

PDFF-CNN: An attention-guided dynamic multi-orientation feature fusion method for gestational age prediction on imbalanced fetal brain MRI dataset.

Fetal brain magnetic resonance imaging (MRI)-based gestational age prediction has been widely used to characterize normal fetal brain development and diagnose congenital brainmalformations. The uncertainty of fetal position and external interference leads to variable localization and direction of the fetal brain. In addition, pregnant women typically concentrate on receiving MRI scans during the fetal anomaly scanning week, leading to an imbalanced distribution of fetal brain MRI data. The above-mentioned problems pose great challenges for deep learning-based fetal brain MRI gestational ageprediction. In this study, a pyramid squeeze attention (PSA)-guided dynamic feature fusion CNN (PDFF-CNN) is proposed to robustly predict gestational ages from fetal brain MRI images on an imbalanced dataset. PDFF-CNN contains four components: transformation module, feature extraction module, dynamic feature fusion module, and balanced mean square error (MSE) loss. The transformation and feature extraction modules are employed by using the PSA to learn multiscale and multi-orientation feature representations in a parallel weight-sharing Siamese network. The dynamic feature fusion module automatically learns the weights of feature vectors generated in the feature extraction module to dynamically fuse multiscale and multi-orientation brain sulci and gyri features. Considering the fact of the imbalanced dataset, the balanced MSE loss is used to mitigate the negative impact of imbalanced data distribution on gestational age predictionperformance. Evaluated on an imbalanced fetal brain MRI dataset of 1327 routine clinical T2-weighted MRI images from 157 subjects, PDFF-CNN achieved promising gestational age prediction performance with an overall mean absolute error of 0.848 weeks and an of 0.904. Furthermore, the attention activation maps of PDFF-CNN were derived, which revealed regional features that contributed to gestational age prediction at each gestationalstage. These results suggest that the proposed PDFF-CNN might have broad clinical applicability in guiding treatment interventions and delivery planning, which has the potential to be helpful with prenatal diagnosis.

Comparison between trans-vaginal and trans-abdominal ultrasound examination of the cervix in the second trimester of pregnancy: a prospective study.

To compare transvaginal (TV) and trans-abdominal (TA) ultrasound assessment of cervical length (CL) at the time of the second-trimester scan for fetal anomalies. This was a prospective study including consecutive pregnant women attending the low-risk ultrasound clinic of two fetal medicine centres in Italy. The inclusion criteria were women between 19+0 and 22+0weeks of gestation, attending the prenatal ultrasound clinic for the routine second trimester screening for fetal anomalies. The primary outcome was to compare the CL measurement obtained at TV compared to TA ultrasound; the secondary outcome was to report the inter and intra-observer variability of CL measured with the two different approaches. All women underwent TV and TA assessment of the cervix performed by two experienced certified operators, blinded to each other. Intra-class correlation coefficients (ICC) and Bland-Altman analyses were used to analyse the data. Two hundred and fifty women were included in the analysis. All women had anteverted uterus. The mean gestational age at ultrasound was 20.7±0.7weeks; 1.2 % (3/250) scans were performed at 19weeks, 49.2 % (123/250) at 20weeks, 44.8 % (112/250) at 21weeks and 4.8 % (12/250) at 22weeks of gestations. Identification of the major landmarks of CL at TA ultrasound was achieved in all the included cases. There was good reliability between CL measured at TA (ICC 0.95, 95 % CI 0.93-0.97 for observer 1 and 0.92 %, 95 % CI0.89-0.94 for observer 2) and TV ultrasound 0.97, 95 % CI0.96-0.98 for observer 1 and 0.96, 95 % CI 0.95-0.97 for observer 2). There was also good reliability between the two observers for both the TA and TV assessment of the CL. Mean TA CL was 41.4±5.5 for observer 1 and 40.5±4.8 for observer 2 with no significant differences between the two measurements (mean difference 0.92 mm, 95 % CI-9.7 to 11.2). Likewise, there was no difference between the CL measured at TV ultrasound between the two observers (mean difference-0.83 mm, 95 % CI-5.97 to 4.30). Finally, there was no difference in the mean CL measured at TA compared to TV, either considering the overall population of women (mean difference:-0.43, 955 CI-8.65 to 7.79), or when stratifying the analysis according to the parity status and the operator. Among experienced operators, there was no difference between TV and TA ultrasound assessment of the CL at the time of the routine anomaly scan for fetal anomaly.

Prenatal diagnosis and clinical outcomes of isolated interruption of the inferior vena cava: an analysis of 12 cases

Objectives: This study aimed to comprehensively investigate the clinical manifestations and outcomes of prenatally diagnosed isolated interrupted inferior vena cava (IIVC) with azygos continuation to shed light on the significance of prenatal diagnosis.&#x0D; &#x0D; Methods: A longitudinal study involved 12 fetuses prenatally diagnosed with IIVC and azygos continuation. Detailed fetal anomaly scans and echocardiography were performed, and pediatric cardiologists confirmed postnatal diagnoses. Genetic testing and extensive follow-ups were also performed.&#x0D; &#x0D; Results: The study confirmed the high diagnostic accuracy of prenatal identification, with 100% postnatal confirmation. Most patients exhibited favorable outcomes, emphasizing the importance of prenatal diagnosis. Genetic testing revealed normal chromosomal arrangements in all tested cases.&#x0D; &#x0D; Conclusion: Our study underscores the vital role of prenatal diagnosis in managing isolated IIVC cases and highlights their generally favorable prognosis. This study contributes to understanding this rare vascular anomaly and its implications for clinical practice.

Spectrum of congenital anomalies of the kidney and urinary tract (CAKUT) including renal parenchymal malformations during fetal life and the implementation of prenatal exome sequencing (WES)

Objectives and backgroundCongenital malformations of the kidney and urinary tract (CAKUT) have a prevalence of 4–60 in 10,000 livebirths and constitute for 40–50% of all end stage pediatric kidney disease. CAKUT can have a genetic background due to monogenetic inherited disease, such as PKD or ciliopathies. They can also be found in combination with extra-renal findings as part of a syndrome. Upon detection of genitourinary malformations during the fetal anomaly scan the question arises if further genetic testing is required. The purpose of this study was to determine the phenotypic presentation of CAKUT cases and the results of exome analysis (WES).MethodsThis is a retrospective analysis of 63 fetal cases with a diagnosis of CAKUT or DSD at a single center between August 2018 and December 2022.ResultsA total of 63 cases (5.6%) out of 1123 matched CAKUT phenotypes including renal parenchyma malformations. In 15 out of 63 WES analysis a pathogenic variant was detected (23.8%). In fetuses with isolated CAKUT the rate of detecting a pathogenic variant on exome sequencing was five out of 44 (11.4%). Ten out of 19 fetuses (52.6%) that displayed extra-renal findings in combination with CAKUT were diagnosed with a pathogenic variant.ConclusionsWES provides an increase in diagnosing pathogenic variants in cases of prenatally detected CAKUT. Especially in fetuses with extra-renal malformations, WES facilitates a gain in information on the fetal genotype to enhance prenatal counselling and management.

Amniotic Band Syndrome – A Case Report

Amniotic Band Syndrome (ABS) encompasses a wide spectrum of abnormalities, all of which result from the entrapment of various parts of the fetal body in the disrupted amniotic fluid. Because of the randomness of entrapment, each affected individual has the potential to develop a unique deficit. Termination of pregnancy is usually suggested at the time of diagnosis of severe abnormalities, while minor limb defects can be repaired by surgery after birth [1]. Here we report a case of amniotic band syndrome detected during fetal anomaly scan at 19w0d gestational age

Comparison of international guidelines on the management of twin pregnancy

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

Does detection of a large for gestational age (LGA) fetus in fetal anomaly scan (FAS) require an early oral glucose screening test (OGTT) and can LGA fetus be detected at birth?

Gestational diabetes mellitus (GDM) complications increase with late diagnosis and late treatment, so early diagnosis and treatment is one of the most important factors in preventing complications. We tried to find an answer to the question of whether the detection of large for gestational age (LGA) fetus in fetal anomaly scan (FAS) requires earlier oral glucose screening test (OGTT) and predicts LGA fetus at birth. Pregnant women who underwent fetal anomaly scan and gestational diabetes screening at the Department of Obstetrics and Gynecology, University of Health Sciences, Tepecik Training and Research Hospital between 2018 and 2020 were included in this large retrospective cohort study. FAS was routinely performed between 18-22 weeks in our hospital. 75 grams of OGTT was used for gestational diabetes screening and it was performed between 24-28 weeks. This large retrospective cohort study was performed on 3,180 fetuses, 2,904 appropriate for gestational age (AGA) and 276 LGA, in the second trimester. The prevalence of GDM was significantly higher in the LGA group (OR 2.44, 95% CI 1.66-3.58; p < 0.001). Insulin requirement for blood glucose regulation was significantly higher in the LGA group (OR 3.6, 95% CI 1.68-7.7; p = 0.001). Fasting and 1st hour OGTT values were similar between the groups, but 2nd hour OGTT values were significantly higher in the second trimester LGA group (p = 0.041). The prevalence of LGA newborns at birth was higher in second trimester LGA fetuses than in fetuses with AGA (21.1% vs. 7.1%, p < 0.001). The fact that the estimated fetal weight (EFW) measured in the second trimester FAS is LGA may be related to GDM in the future and LGA fetus at birth. A more detailed GDM risk questioning should be performed to these mothers and OGTT should be considered when additional risk factors are detected. In addition to all these, glucose regulation may not be possible with diet alone in mothers who have LGA in the second trimester ultrasound and who may have GDM in the future. These mothers should be monitored more closely and more carefully.

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

Introductionplacental 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. Methodsthis 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. ResultsIVF 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. DiscussionIVF 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.

Detection rates of a national fetal anomaly screening programme: A national cohort study.

To measure condition-specific detection rates for 14 physical conditions screened for by the NHS fetal anomaly screening programme (FASP) fetal anomaly (FA) ultrasound scan. Retrospective audit of 12 694 diagnoses across a 3-year national cohort. All English NHS and crown-dependency hospital trusts providing maternity services. Pregnancies booked for maternity services with an expected date of delivery between 1 April 2017 and 31 March 2020 and at least one diagnosis of a condition screened for by FASP. Active multi-source ascertainment, linkage, audit and validation of clinical information to identify the subset of diagnoses meeting the condition-specific positivity threshold for the FA scan. The accuracy of the FA scan compared with diagnostic reference standards. FA scan detection rates were: anencephaly 96.3% (95% confidence interval [CI] 81.7-99.3%), atrioventricular septal defect: 69.2% (95% CI 65.8-72.4%), bilateral renal agenesis: 98.7% (95% CI 95.4-99.6%), cleft lip: 89.5% (95% CI 87.8-90.9%), congenital diaphragmatic hernia: 60.8% (95% CI 56.5-65%), Edwards syndrome: 73.8% (95% CI 67.5-79.3%), exomphalos: 59.4% (95% CI 49.4-68.7%), gastroschisis: 88.6% (95% CI 79-94.1%), hypoplastic left heart syndrome: 92.7% (95% CI 90-94.8%), lethal skeletal dysplasia: 93.2% (95% CI 88.6-96%), Patau syndrome: 82.3% (95% CI 72.4-89.1%), spina bifida: 93.8% (95% CI 91.8-95.3%), tetralogy of Fallot: 75.4% (95% CI 72.1-78.4%) and transposition of the great arteries: 84.9% (95% CI 81.7-87.5%). The performance of the FA scan is above the expectations set in 2010 for most conditions. For the remaining conditions, the majority of fetuses and babies affected are detected before the FA scan.

Uniform International Method to Measure Cervical Length: Are We There Yet?

Introduction: Cervical length is an important predictor of spontaneous preterm birth. So far, the best way to measure cervical length has not been established. We aimed to compare the incidence of short cervical length between three methods of cervical length measurement with and without the inclusion of cervico-isthmic complex (CIC) (six methods in total) and to determine the positive predictive value for spontaneous preterm birth. Material and Methods: We performed a prospective single-center cohort study in women with a singleton pregnancy between August 2014 and December 2018. During the routine fetal anomaly scan (18–22 weeks), women were offered transvaginal ultrasound for cervical length measurement to screen for the risk of spontaneous preterm birth. Each cervix was measured in six different ways: single-line, two-line, and tracing method between the internal and external os of the cervix with and without CIC. We evaluated the predictive value of the different measurements for spontaneous delivery before 37 weeks using positive predictive values. Results: Our final study population comprised 1,691 women. The overall rate of preterm birth <37 weeks was 8.0% (4.6% spontaneous, 3.4% iatrogenic preterm birth). The mean gestational age at cervical length measurement was 19+6 weeks. The different measuring techniques resulted in significant different cervical lengths, showing a maximum difference of >8 mm between the techniques (41.04 mm [SD 7.1] with one-line without CIC and 49.18 [SD 9.05] mm with trace with CIC) with an incidence of short cervical length below <25 mm ranging from 0.4% to 1.1% (p = 0.18). The positive predictive values for spontaneous preterm birth <37 weeks ranged from 42.9% to 20.0%. Conclusion: Different measurement methods for cervical length resulted in statistically significant differences in measured cervical length. Depending on the chosen cut-off this translates to different incidences of short cervical length and influences the number of women designated as high risk for preterm birth and receiving treatment. For interpretation and comparability between (inter-) national studies, it is important to adequately report on the employed technique. Future research should focus on determining the optimal measuring technique and a universal method of measurement.

261. The diagnostic accuracy of fetal cardiac anomaly scans to postnatal cardiac defects

Introduction and aim: To evaluate the diagnostic accuracy, including sensitivity and specificity of routine anomaly ultrasound, performed between 18 to 24 weeks of gestation, in detecting fetal cardiac defects. The antenatal cardiac defects were compared to the gold standard, which was defined as the postnatal echocardiography and the post-mortem findings from autopsy reports. The study also identified the number and type of cardiac anomalies detected antenatally on ultrasound and those detected postnatally, together with maternal and fetal risk factors for CHDs. Method: A hospital based retrospective, observational, quantitative and comparative research method was adopted. The cardiac defects detected on anomaly ultrasound scan, from the initiation of the anomaly screening programme in January 2016 up to August 2018 (with births occurring by January 2019), were compared to the postnatal echoes performed by the Paediatric cardiologist or to the post-mortem findings derived from autopsy results.Results: In the study period, 139 babies were diagnosed with CHD postnatally of which 93 had had a fetal anomaly scan. A total of 29 cases of CHD were detected antenatally, from which 28 were confirmed postnatally with complete agreement in 20 cases. The sensitivity of anomaly scans in the detection of CHDs was observed to be 30.43% and the specificity of 99.98%. The positive predictive value (PPV) was observed at 96.55% and the negative predictive value (NPV) at 99.24%. The commonest diagnosed CHD was a ventricular septal defect (VSD) while the incidence of CHDs was 18.15 per 1000 live births. Conclusion: There was complete agreement in 68.97% of cases when the antenatal findings on anomaly ultrasound scan were compared to the gold standard. A moderate sensitivity was obtained with an excellent specificity, PPV and NPV. In the population the incidence of total CHDs was observed to be 18.15 per 1000 live births.