Nuchal translucency and other first-trimester sonographic markers of chromosomal abnormalities

First-Trimester Morphological Evaluation of Fetuses and Medical Law Implications

Background/Objectives: Over the years, the potential of the first-trimester (FT) ultrasound in the detection of fetal structural defects has increased. The main objectives of the first-trimester fetal screening evaluation are the detection of major structural anomalies and the diagnosis of additional sonographic markers for chromosomal disorders. When a fetal anomaly is diagnosed, patients have the right to be informed about the risks, necessary interventions, or alternatives. Depending on the severity of the anomalies and the pregnancy period, the legality of the pregnancy termination was evaluated. The aim of this study was to assess the impact of the first-trimester morphological screening of the fetus using an ultrasound protocol according to the latest international protocols (the ISUOG protocol). Methods: Between 1 January 2024 and 31 December 2024, 854 pregnancies with gestational ages between 11 weeks and 13 weeks + 6 days were morphologically evaluated during the nuchal scan in the Obstetrics and Gynecology Department of the Emergency County Hospital from Craiova. Both transabdominal and transvaginal ultrasound in 2D and in a color Doppler mode were used in the scanning technique. The ultrasound findings were correlated with the genetic testing results and pregnancy outcome. The medical law implications were related to the cases where the ultrasound was performed at about 13 weeks of gestation, and the screening genetic results showed an increased pregnancy risk, which arose during the FT. In these cases, we performed amniocentesis at about 16-17 weeks of gestation, and especially, the Non-Invasive Prenatal Testing (NIPT)-positive cases were confirmed by karyotyping. Still, at this gestational age of diagnosis, the Romanian law would not allow abortions. Results: By using this extended FT ultrasound protocol, we detected 58 cases with fetal structural anomalies. Eighteen cases were also associated with genetic syndromes after performing chorionic villous sampling (CVS). Three cases detected with minor structural anomalies (two cases with club foot and one case with a cleft upper lip) were lost to follow-up. Conclusions: Fetal morphological ultrasound evaluation is feasible in the late first trimester. By using an extended ultrasound protocol, we can detect most of the fetal structural anomalies and contribute to better medical counseling and improve pregnancy outcomes.

Prenatal diagnosis following preimplantation genetic testing (PGT): recommendations of the Italian Society of Human Genetics (SIGU)

This document aims to provide good practice recommendations in order to support maternal-foetal medicine specialists, clinical geneticists and clinical laboratory geneticists in the management of pregnancies obtained after the transfer of an embryo tested with preimplantation genetic testing (PGT). It was drafted by geneticists expert in preimplantation genetics and prenatal genetic diagnosis belonging to the "Working Group in Cytogenomics, Prenatal and Reproductive Genetics" of the "Italian Society of Human Genetics" (SIGU). In particular, the paper addresses the diagnostic algorithm to be applied in prenatal follow-up depending on the type of PGT performed, the results obtained and the related diagnostic value based on the most recent literature data and Italian and international recommendations.

Routine 36-week scan: prediction of small-for-gestational-age neonate

OBJECTIVES

First, to compare the predictive performance of routine ultrasonographic estimated fetal weight (EFW) at 31 + 0 to 33 + 6 and 35 + 0 to 36 + 6 weeks' gestation for delivery of a small-for-gestational-age (SGA) neonate. Second, to compare the predictive performance of EFW at 36 weeks' gestation for SGA vs fetal growth restriction (FGR) at birth. Third, to compare the predictive performance for delivery of a SGA neonate of EFW < 10th percentile vs a model combining maternal demographic characteristics and elements of medical history with EFW.

METHODS

This was a retrospective analysis of prospectively collected data in 21 676 women with a singleton pregnancy who had undergone routine ultrasound examination at 31 + 0 to 33 + 6 weeks' gestation and 107 875 women with a singleton pregnancy who had undergone routine ultrasound examination at 35 + 0 to 36 + 6 weeks. Measurements of fetal head circumference, abdominal circumference and femur length were used to calculate EFW according to the Hadlock formula and this was expressed as a percentile according to the Fetal Medicine Foundation fetal and neonatal population weight charts. The same charts were used to diagnose SGA neonates with birth weight < 10th or < 3rd percentile. FGR was defined as birth weight < 10th percentile in addition to Doppler anomalies. For each gestational-age window at screening, the screen-positive rate and detection rate were calculated at different EFW cut-offs between the 10th and 50th percentiles for predicting the delivery of a SGA neonate with birth weight < 10th or < 3rd percentile, either within 2 weeks or at any time after assessment. The areas under the receiver-operating-characteristics curves (AUC) of screening for a SGA neonate by EFW at 31 + 0 to 33 + 6 weeks and at 35 + 0 to 36 + 6 weeks were compared.

RESULTS

The predictive performance of routine ultrasonographic examination during the third trimester for delivery of a SGA neonate is higher if: first, the scan is carried out at 35 + 0 to 36 + 6 weeks' gestation rather than at 31 + 0 to 33 + 6 weeks; second, the outcome measure is birth weight < 3rd rather than < 10th percentile; third, the outcome measure is FGR rather than SGA; fourth, if delivery occurs within 2 weeks after assessment rather than at any time after assessment; and fifth, prediction is performed using a model that combines maternal demographic characteristics and elements of medical history with EFW rather than EFW < 10th percentile alone. At 35 + 0 to 36 + 6 weeks' gestation, detection of ≥ 85% of SGA neonates with birth weight < 10th percentile born at any time after assessment necessitates the use of EFW < 40th percentile. Screening at this percentile cut-off predicted 95% and 98% of neonates with birth weight < 10th and < 3rd percentile, respectively, born within 2 weeks after assessment, and the respective values for neonates born at any time after assessment were 85% and 93%.

CONCLUSION

Routine third-trimester ultrasonographic screening for a SGA neonate performs best when the scan is carried out at 35 + 0 to 36 + 6 weeks' gestation, rather than at 31 + 0 to 33 + 6 weeks, and when EFW is combined with maternal risk factors to estimate the patient-specific risk. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Early Prediction of Gestational Diabetes Mellitus and Insulin Therapy Requirement Using First-Trimester PAPP-A and Free β-hCG MoMs Levels: A Retrospective Case-Control Study

Objectives: To evaluate the association between gestational diabetes mellitus (GDM), including insulin-dependent GDM with pregnancy-associated plasma protein-A (PAPP-A) multiples of the median (MoM) and free beta human chorionic gonadotropin (free β-hCG) MoM levels, and to assess their potential as predictive risk factors. Methods: This retrospective study included 2588 women with singleton pregnancies who underwent combined first-trimester screening, along with the 50 g glucose challenge test (GCT) and a 100 g oral glucose tolerance test (OGTT) between 24 and 28 weeks of gestation. Patients were initially divided into four groups based on the glucose screening results, and PAPP-A and free β-hCG MoMs were compared between these groups. GDM cases managed by diet were then compared with those requiring insulin therapy. Results: Of the study population, 132 women (5.10%) were diagnosed with GDM, 112 (84.8%) managed their glycemia with dietary changes, while 20 (15.2%) required insulin therapy. PAPP-A levels were significantly lower in the GDM group compared to the control group (p < 0.001). In addition, the insulin-dependent GDM group had significantly lower PAPP-A levels than the diet-controlled group (p < 0.001). No significant differences were observed in the free β-hCG MoM levels between the groups (p = 0.292). Receiver operating characteristic analysis identified 0.815 as the optimal PAPP-A cut-off value for predicting GDM, with a sensitivity of 61.4%, specificity of 61.6%, and an area under the curve (AUC) of 0.649 (95% CI: 0.595-0.703). For insulin-dependent GDM, the same threshold yielded an AUC of 0.621 (95% CI: 0.563-0.679), with a sensitivity of 58.6% and a specificity of 59.7%. Conclusions: Low serum PAPP-A MoM levels are significantly associated with the development of GDM, including insulin-dependent cases. Although PAPP-A alone may not be a definitive predictive marker for GDM, low levels could support the recommendation for early screening as part of a broader diagnostic approach.

Identification of Putative Biomarkers in Cerebral Palsy: A Meta-Analysis and Meta-Regression

BACKGROUND

Cerebral palsy (CP) is a neurological disorder that impairs motor abilities. Identifying maternal biomarker derangements can facilitate further evaluation for early diagnosis, potentially leading to improved clinical outcomes. This study investigates the association between maternal biomarker derangements and CP development during the antenatal period.

METHODS

A systematic search was conducted in MEDLINE, EMBASE, and Cochrane databases, following MOOSE guidelines. Data on participants exceeding biomarker thresholds (95th and 5th percentiles) were extracted for combined odds ratio estimation. Geometric mean differences, reported as multiples of the median (MoMs), were used to analyze changes in marker levels. Trimesterwise subgroup analysis and metaregression assessed the impact of variables on outcomes.

RESULTS

Five observational studies (1552 cases, 484,985 controls) revealed lower maternal pregnancy-associated plasma protein A levels were associated with CP (pooled odds ratio [OR] = 1.60, 95% confidence interval [CI] = 1.22 to 2.09; I = 0%), with a -0.04 MoM geometric mean difference. Lower maternal beta-human chorionic gonadotropin (HCG) levels in first and second trimesters indicated a pooled OR = 1.18 (95% CI = 0.85 to 1.63; I = 57%). Sensitivity analysis showed an OR = 1.40 (95% CI = 1.08 to 1.82; I = 0%), with a -0.07 MoM geometric mean difference. Metaregression identified primigravida status as negatively influencing beta-HCG levels. Elevated nuchal translucency values and CP presented a pooled OR = 1.06 (95% CI = 0.77 to 1.44; I = 0%).

CONCLUSION

Lower maternal pregnancy-associated plasma protein A levels during the first trimester and lower beta-HCG levels in the first and second trimesters are associated with CP development in children. Future research should validate the predictive utility of these biomarkers and explore novel ones through large-scale cohort studies.

False-Positive Diagnosis of Congenital Heart Defects at First-Trimester Ultrasound: An Italian Multicentric Study

Objective. Our objective was to assess the proportion of false-positive CHD cases at the first-trimester evaluation of the fetal heart, performed by experienced operators. Methods. This multicenter retrospective study included of pregnant women with suspicion of CHDs during first-trimester screening for aneuploidies. In all cases, the fetal heart assessments were performed by obstetricians with extensive experience in first-trimester scanning, following an extended protocol proposed by SIEOG national guidelines, which included an axial view of the fetal abdomen and chest to assess visceral situs and evaluation of the four-chamber view (4CV) and three-vessel trachea view (3VTV) with color Doppler. In all suspected cases, fetal echocardiography was offered within 16 and/or at 19-22 weeks' gestation. Results. From a population of 4300 fetuses, 46 CHDs were suspected. Twenty-four cases were excluded from this analysis because the parents opted for early termination of the pregnancies due to associated structural and/or genetic anomalies. For the remaining 22, echocardiography was performed by 16 weeks in 14 cases (64%) and after 16 weeks in 8 cases. In 19 cases (86.4%), a fetal cardiologist confirmed the presence of a CHD. In three cases (13%), the cardiac anatomy was found to be normal at the fetal echocardiography and postnatally. Conclusions. This study shows that the proportion of false-positive cases at the first-trimester ultrasound examination of the fetal heart, performed by experienced operators, may carry a higher risk of false-positive diagnosis than expected. Therefore, this issue must be discussed in instances where a CHD is suspected at the first-trimester screening.

Development of a 3D-printed nuchal translucency model: a pilot study for prenatal ultrasound training

BACKGROUND

We used two 3D ultrasound volumes of fetal heads at 13 weeks to create live-size 3D-printed phantoms with a view to training or assessment of diagnostic abilities for normal and abnormal nuchal translucency measurements. The phantoms are suitable for use in a water bath, imitating a real-life exam. They were then used to study measurement accuracy and reproducibility in examiners of different skill levels.

METHODS

Ultrasound scans of a 13 + 0-week fetus were processed using 3D Slicer software, producing a stereolithography file for 3D printing. The model, crafted in Autodesk Fusion360™, adhered to FMF guidelines for NT dimensions (NT 2.3 mm). Additionally, a model with pathologic NT was designed (NT 4.2 mm). Printing was performed via Formlabs Form 3® printer using High Temp Resin V2. The externally identical looking 3D models were embedded in water-filled condoms for ultrasound examination. Eight specialists of varying expertise levels conducted five NT measurements for each model, classifying them in physiological and abnormal models.

RESULTS

Classification of the models in physiological or abnormal NT resulted in a detection rate of 100%. Average measurements for the normal NT model and the increased NT model were 2.27 mm (SD ± 0.38) and 4.165 mm (SD ± 0.51), respectively. The interrater reliability was calculated via the intraclass correlation coefficient (ICC) which yielded a result of 0.883, indicating robust agreement between the raters. Cost-effectiveness analysis demonstrated the economical nature of the 3D printing process.

DISCUSSION

This study underscores the potential of 3D printed fetal models for enhancing ultrasound training through high inter-rater reliability, consistency across different expert levels, and cost-effectiveness. Limitations, including population variability and direct translation to clinical outcomes, warrant further exploration. The study contributes to ongoing discussions on integrating innovative technologies into medical education, offering a practical and economical method to acquire, refine and revise diagnostic skills in prenatal ultrasound. Future research should explore broader applications and long-term economic implications, paving the way for transformative advancements in medical training and practice.

Test performance and clinical utility of expanded non-invasive prenatal test: Experience on 71,883 unselected routine cases from one single center

OBJECTIVE

The balance between benefits and risks of discordant outcomes makes the Genome-Wide Non-Invasive Prenatal Test (GW-NIPT) controversial. This study aims to evaluate performance and clinical utility in a wide cohort of unselected clinical cases from a single center when a standardized protocol is applied and integrated with a secondary algorithm for data interpretation.

METHOD

In 2 years, over 70,000 pregnant patients underwent GW-NIPT for fetal common trisomies, sex chromosome aneuploidies, rare autosomal aneuploidies, segmental abnormalities (CNVs ≥ 7 Mb) and microdeletions (CNVs < 7 Mb). All samples were uniformly processed with Veriseq NIPT Solution v2 and analyzed using all data metrics along with a home-made algorithm for sequencing data analysis. Results were retrospectively reviewed for clinical outcomes.

RESULTS

Among 71,883 eligible cases including twin pregnancies, 1011 (1.4%) received a positive result and 781 were confirmed by invasive prenatal diagnosis. Clinical sensitivity ranged from 99.65% for common trisomy (T21, T18, T13) to 83.33% for microdeletions, while specificity remained high (99.98%) for each class of fetal abnormalities detected.

CONCLUSIONS

Integrating a standardized protocol with an internal algorithm allowed discordant results to be reduced, yielding high accuracy. Observed reliability in detecting genome-wide chromosomal conditions reinforced the expanded NIPT utility in clinical practice.

The 'Radiant Effect': Recent Sonographic Image-Enhancing Technique and Its Impact on Nuchal Translucency Measurements

Background: This study assesses the effects of the 'Radiant' image enhancement technique on fetal nuchal translucency (NT) measurements during first-trimester sonographic exams. Methods: A retrospective analysis of 263 ultrasound images of first-trimester midsagittal sections was conducted. NT measurements were obtained using a semi-automatic tool. Statistical methods were applied to compare NT measurements with and without 'Radiant' enhancement. An in vitro setup with predefined line distances provided additional data. Results: Incremental increases in NT measurements were observed with varying levels of 'Radiant' application: an average increase of 0.19 mm with 'Radiant min', 0.24 mm with 'Radiant mid', and 0.30 mm with 'Radiant max.' The in vitro results supported these findings, showing consistent effects on line thickness and measurement accuracy, with the smallest mean deviation occurring at the 'Radiant mid' setting. Conclusions: 'Radiant' image enhancement leads to significant increases in NT measurements. To avoid systematic biases in clinical assessments, it is advisable to disable 'Radiant' during NT measurement procedures. Further studies are necessary to corroborate these findings and to consider updates to the NT reference tables based on this technology.

Cervical pessary to prevent preterm birth and poor neonatal outcome: An integrity meta-analysis of randomized controlled trials focusing on adherence to the European Medical Device Regulation

BACKGROUND

Findings from randomized trials (RCTs) on cervical pessary treatment to prevent spontaneous preterm birth are inconsistent.

OBJECTIVES

Our hypothesis suggests that adhering to the European Medical Device Regulation (MDR) and following the instructions for use are essential prerequisites for successful therapy. Conversely, the non-adherence to these guidelines will probably contribute to its failure.

SEARCH STRATEGY AND SELECTION CRITERIA

Based on validated criteria from integrity assessments we performed a systematic review identifying 14 RCTs evaluating the effect of cervical pessaries.

DATA COLLECTION AND ANALYSIS

We analyzed the implications of 14 criteria each accounting for 0-2 points of a score reflecting the clinical evaluation plan (CEP) as proposed by the MDR to evaluate the risk-benefit ratio of medical devices.

MAIN RESULTS

Seven RCTs in each singleton and twin pregnancies (5193 "cases") were included, detecting a high heterogeneity within control groups (I2 = 85% and 87%, respectively, P < 0.01). The CEP score varied from 11 to 26 points for all studies. The most common reasons for low scores and potential data compromise were poor recruitment rates, no (completed) power analysis, and no pre-registration, but mainly non-adherence to technical, biological, and clinical equivalence to the instructions for use as required by the MDR. All trials with score values greater than 20 had applied audit procedures. Within this group we found significantly reduced rates of spontaneous preterm birth at less than 34 weeks within the pessary group in singleton (odds ratio 0.28; 95% confidence interval 0.12-0.65) and twin pregnancies (odds ratio 0.30; 95% confidence interval 0.13-0.67). Similarly, there was a significant reduction in the composite poor neonatal outcome in singleton (odds ratio 0.25; 95% confidence interval 0.10-0.61) and twin pregnancies (odds ratio 0.54; 95% confidence interval 0.35-0.82) after a pessary as compared with controls.

CONCLUSION

Non-audited RCTs and meta-analyses mixing studies of different clinical quality as pre-defined by a CEP and the MDR pose the risk for erroneous conclusions.

Cell‑free fetal DNA at 11‑13 weeks of gestation is not altered in complicated pregnancies

Non-invasive maternal cell-free fetal DNA (cffDNA) is a promising biomarker for screening common genetic syndromes. Alterations in the expression levels of cffDNA in the maternal circulation have been demonstrated in abnormal pregnancies. However, the results are conflicting. The present study aimed to investigate whether cffDNA levels are associated with pregnancy complications. The study group comprised pregnant women who presented with pregnancy complications, such as preterm birth, gestational hypertension, intrauterine growth retardation, gestational diabetes, polyhydramnios, oligohydramnios, vaginal bleeding and placental abruption. The control group comprised women who had a normal pregnancy course. Blood samples were obtained from 500 pregnant women between 11-13 weeks of gestation. cffDNA was amplified, sequenced and analyzed using the next-generation aneuploidy test of a Panorama-Natera kit. Nuchal translucency (NT) thickness as well as pregnancy associated plasma protein-A (PAPP-A) and β-human chorionic gonadotropin (β-hCG) levels were also assessed. Statistical analysis was performed in 494 out of the 500 samples collected with SPSS v.26 using non-parametric methods. The parameters were normalized by the multiples of median (MoM) method. The expression levels of PAPP-A, β-hCG, and the NT mean MoM values were significantly different between the study and control groups (P=0.005, P<0.001 and P=0.007, respectively). However, the expression levels of cffDNA and the mean MoM values were not significantly different between these two groups (P=0.687). The findings of the present study support the conclusion that cffDNA expression is not altered in a series of pregnancy complications. The prognostic value of cffDNA in predicting adverse pregnancy outcomes requires further investigation.

Limited ability of increased sequencing depth in detecting cases missed by noninvasive prenatal testing: a comparative analysis of 3 clinical cases

Increased sequencing depth can improve the detection rate of noninvasive prenatal testing (NIPT) for chromosome aneuploidies and copy number variations (CNVs). However, due to the technical limitations of NIPT, false-positives and false-negatives are inevitable. False-positives for aneuploidy and CNVs have been widely reported, but few missed cases have been reported. In this study, we report 3 patients missed by NIPT, which were still missed after increasing the sequencing depth. To verify the detection efficiency of the platform, the results of NIPT in 32,796 patients treated in Yulin Women and Children Health Care Hospital from 2020 to 2022 were retrospectively analyzed. Data on false-negative cases found by postnatal follow-up or amniocentesis were collected, and the sequencing data, pregnancy examination data, and postnatal follow-up results of these missed patients were summarized. Five patients missed by NIPT were found, and they were missed again by retesting or increasing the sequencing depth. Except for hypospadias found in 1 patient, ultrasonography of the other 4 patients showed no obvious abnormalities during the whole pregnancy. Our results suggest that pregnant women should be fully informed of the benefits and limitations of NIPT before undergoing the examination to avoid unnecessary medical disputes.

Diagnostic yield of copy number variation sequencing in fetuses with increased nuchal translucency: a retrospective study

OBJECTIVE

To assess the efficacy of copy number variation sequencing (CNV-seq) and karyotyping for prenatal detection of chromosomal abnormalities in fetuses with increased nuchal translucency.

METHODS

Amniotic fluid samples were extracted from 205 fetuses with increased nuchal translucency (NT ≥ 2.5 mm), diagnosed by ultrasound between gestational ages of 11 and 13 + 6 weeks. Karyotyping and CNV-seq were performed for detecting chromosomal abnormalities.

RESULTS

There are 40 fetuses (19.51%) showing increased NT detected with chromosomal abnormalities in karyotyping, and trisomy 21 was found to be the most common abnormalities. There are 50 fetuses (24.39%) identified with chromosomal abnormalities by CNV-seq. The detection of the applied techniques indicated that CNV-seq revealed higher chromosomal aberrations. The risk of chromosomal abnormalities was significantly increased with NT thickening, from 13.64% in the NT group of 2.5-3.4 mm, 38.64% in the NT group of 3.5-4.4 mm, and to 51.72% in the NT group of over 4.5 mm (P < 0.05). The investigated cases with increased NT with presence of soft markers in ultrasound or high risk in non-invasive prenatal testing presented chromosomal abnormalities in higher rates, comparing with those with isolated NT or low risk (P < 0.05).

CONCLUSION

The results indicated that the risk of chromosomal abnormalities was associated with the NT thickness, detected by karyotype or CNV-seq. The combination application of two analysis was efficient to reveal the possible genetic defects in prenatal diagnosis. The finding suggested that the detection should be considered with ultrasonographic soft markers, and the NT thickness of 2.5-3.4 mm could be a critical value for detecting chromosomal abnormalities to prevent the occurrence of missed diagnosis.

A new model based on artificial intelligence to screening preterm birth

OBJECTIVE

The objective of this study is to create a new screening for spontaneous preterm birth (sPTB) based on artificial intelligence (AI).

METHODS

This study included 524 singleton pregnancies from 18th to 24th-week gestation after transvaginal ultrasound cervical length (CL) analyzes for screening sPTB < 35 weeks. AI model was created based on the stacking-based ensemble learning method (SBELM) by the neural network, gathering CL < 25 mm, multivariate unadjusted logistic regression (LR), and the best AI algorithm. Receiver Operating Characteristics (ROC) curve to predict sPTB < 35 weeks and area under the curve (AUC), sensitivity, specificity, accuracy, predictive positive and negative values were performed to evaluate CL < 25 mm, LR, the best algorithms of AI and SBELM.

RESULTS

The most relevant variables presented by LR were cervical funneling, index straight CL/internal angle inside the cervix (≤ 0.200), previous PTB < 37 weeks, previous curettage, no antibiotic treatment during pregnancy, and weight (≤ 58 kg), no smoking, and CL < 30.9 mm. Fixing 10% of false positive rate, CL < 25 mm and SBELM present, respectively: AUC of 0.318 and 0.808; sensitivity of 33.3% and 47,3%; specificity of 91.8 and 92.8%; positive predictive value of 23.1 and 32.7%; negative predictive value of 94.9 and 96.0%. This machine learning presented high statistical significance when compared to CL < 25 mm after T-test (p < .00001).

CONCLUSION

AI applied to clinical and ultrasonographic variables could be a viable option for screening of sPTB < 35 weeks, improving the performance of short cervix, with a low false-positive rate.

Elevated nuchal translucency, is it time to discuss the cut off?

OBJECTIVE

We aimed to evaluate pregnancy and postnatal outcomes of fetuses with NT between 95th and 99th percentile at first trimester and whether they could benefit from further investigations rather that routine scans.

METHODS

Multicenter retrospective observational study which involved all cases with NT between 95th and 99th percentile from January 2015 to December 2020. Unfavorable outcome was considered as: miscarriage or intrauterine fetal death (IUFD), chromosomal abnormality/genetic syndrome, major malformation or neurodevelopmental delay. Study population outcomes were compared with general population.

RESULTS

The rate of unfavorable outcome was 25.44% (167 out of 667). We reported: 6 (0.90%) second trimester miscarriage or IUFD, 90 (13.49%) chromosomal abnormalities/genetic syndromes, 57 (8.55%) major malformations, 13 (1.95%) cases of neurodevelopmental delay. The incidence of chromosomal abnormalities/genetic syndromes and major malformations were significantly higher (OR 6.99 (IC 95% 4.33-11.28), P < 0.001 and OR 17.77 (IC 95%7.22-43.75), P < 0.001 respectively) compared to the general population. The incidence of neurodevelopmental delay was not increased (OR of 0.64 CI 95% 0.33-1.24 P = 0.185).

CONCLUSIONS

Fetuses with NT between 95th and 99th percentile have an increased risk of pregnancy and postnatal adverse outcomes. According to our data it is reasonable to consider a lower cut of NT (NT > 95th percentile) for offering further investigations such as detailed ultrasound scan, fetal echocardiography and counseling where the option of performing fetal karyotype and CGH array should be discussed.

Identification of Fetuses at Increased Risk of Trisomies in the First Trimester Using Axial Planes

INTRODUCTION

The measurement of nuchal translucency (NT) is crucial for assessing risk of aneuploidies in the first trimester. We investigate the ability of NT assessed by a transverse view of the fetal head to detect fetuses at increased risk of common aneuploidies at 11-13 weeks of gestation.

METHODS

We enrolled a nonconsecutive series of women who attended our outpatient clinic from January 2020 to April 2021 for aneuploidy screening by means of a first trimester combined test. All women were examined by operators certified by the Fetal Medicine Foundation. In each patient, NT measurements were obtained both from the median sagittal view and transverse view. We calculated the risk of aneuploidy using NT measurements obtained both with sagittal and axial scans, and then we compared the results.

RESULTS

A total of 1,023 women were enrolled. An excellent correlation was found between sagittal and transverse NT measurements. The sensitivity and specificity of the axial scan to identify fetuses that were deemed at risk of trisomy 21 using standard sagittal scans were 40/40 = 100.0% (95% confidence interval [CI]: 91.2-100.0) and 977/983 = 99.4% (95% CI: 98.7-99.7), respectively. The sensitivity and specificity of the axial scan to identify fetuses at risk of trisomy 13 or 18 were 16/16 = 100.0% (95% CI: 80.6-100.0) and 1,005/1,007 = 99.8% (95% CI: 99.3-99.9).

CONCLUSIONS

When the sonogram, a part of combined test screening, is performed by an expert sonologist, axial views can reliably identify fetuses at increased risk of trisomies without an increase in false negative results.

[Management of isolated increased nuchal translucency: survey among the Pluridisciplinary Centers for Prenatal Diagnosis]

OBJECTIVES

The management for isolated increased nuchal translucency (NT) in the first trimester with a normal karyotype and normal Chromosomal Microarray Analysis (CMA) is not consensual. The aim was to perform a survey among the Pluridisciplinary Centers for Prenatal Diagnosis (CPDPN) in France regarding their management of increased NT in the first trimester.

METHODS

We conducted a multicenter descriptive survey between September 2021 and October 2021 among the 46 CPDPNs of France.

RESULTS

The response rate was 56.5% (n = 26/46). The NT thickness threshold for which invasive diagnosis testing is performed is 3.0mm in 23.1% of centers (n = 6/26) and 3.5mm in 76.9% of centers (n = 20/26). A CMA was performed alone in 26.9% of centers (n = 7/26) while 7.7% of centers (n = 2/26) did not perform a CMA. The gestational age for the first reference ultrasound scan was 16 to 18 WG in 88.5% of centers (n = 23/26), while it was not performed before 22 WG in 11.5% of centers (n = 3/26). Fetal echocardiography is proposed systematically in 73.1% of centers (n = 19/26).

CONCLUSION

There is heterogeneity in the management of increased NT in the first trimester among the CPDPNs in France. In case of increased NT on first trimester ultrasound scan, the NT thickness threshold for which invasive diagnosis testing is performed varies from 3.0 mm or 3.5mm depending on the center. Moreover, CMA and early reference morphological ultrasound scan between 16 and 18 WG were not systematically performed, despite the current data suggesting their interest.

The Levels of Pregnancy-Associated Plasma Protein (PAPP-A) and Chorionic Gonadotropin (β-hCG) in the Blood Serum of Women with Hypothyroidism in the 1st Trimester of Pregnancy

Introduction

Hypothyroidism occurs in pregnant women at a rate of 0.3% to 3%. The deficiency of thyroid hormones during pregnancy can lead to an increased risk of pregnancy complications and poor health of the child, particularly affecting its psychomotor development due to the intensive growth of the nervous system during gestation. The study attempted to establish the median concentrations of pregnancy-associated plasma protein PAPP-A and the free subunit of human chorionic gonadotropin β-hCG in women with hypothyroidism in the 1st trimester of pregnancy.

Objective

The study attempted to establish the median concentrations of pregnancy-associated plasma protein PAPP-A and the free subunit of human chorionic gonadotropin β-hCG in women with hypothyroidism in the 1st trimester of pregnancy.

Patients and methods

The study included 210 pregnant women between 11 and 13.6 weeks of pregnancy; 105 women were diagnosed with hypothyroidism before or during pregnancy, and 105 women of a similar body weight and gestational age had normal thyroid function.The measurements of the pregnancy parameters studied were performed using the DELFIA^® Xpress system.

Results

Differences in the multiples of the median of the PAPP-A and β-hCG levels between women with hypothyroidism and healthy women were observed.

Conclusion

Introducing correction for patients with hypothyroidism during non-invasive biochemical prenatal testing may allow obtaining more reliable results that would be the basis for referral to invasive procedures.

Increased nuchal translucency can be ascertained using transverse planes

BACKGROUND

The detection of increased nuchal translucency is crucial for the assessment risk of aneuploidies and other fetal anomalies.

OBJECTIVE

This study aimed to investigate the ability of a transverse view of the fetal head to detect increased fetal nuchal translucency at 11 to 13 weeks of gestation.

STUDY DESIGN

This was a prospective study enrolling a nonconsecutive series of women who attended our outpatient clinic from January 2020 to April 2021 for combined screening and were examined by operators certified by the Fetal Medicine Foundation. In each patient, nuchal translucency measurements were obtained both from a median sagittal view and from a transverse view. A second sonologist blinded to the results of the first examination obtained another measurement to assess intermethod and interobsever reproducibility.

RESULTS

A total of 1023 women were enrolled. An excellent correlation was found between sagittal and transverse nuchal translucency measurements, with a mean difference of 0.01 mm (95% confidence interval, -0.01 to 0.02). No systematic difference was found between the 2 techniques. The inter-rater reliability (intraclass correlation coefficient, 0.957; 95% confidence interval, 0.892-0.983) and intrarater reliability (intraclass correlation coefficient, 0.976; 95% confidence interval, 0.941-0.990) of axial measurements were almost perfect. Transverse measurements of 3.0 mm identified all cases with sagittal measurements of ≥3.0 with a specificity of 99.7%; transverse measurements of >3.2 mm identified all cases with sagittal measurements of 3.5 mm with a specificity of 99.7%. The time required to obtain transverse nuchal translucency measurements was considerably shorter than for sagittal measurements, particularly when the fetus had an unfavorable position.

CONCLUSION

When the sonogram is performed by an expert sonologist, the difference in nuchal translucency measurement obtained with a transverse or sagittal plane is minimal. Increased nuchal translucency can be reliably identified by using transverse views, and in some cases, this may technically be advantageous.

Behavior of the Genetic Markers at Screening during the First Trimester of Pregnancy in Euploid Fetuses

OBJECTIVE

 This study aims to describe the behavior of chromosomopathy screenings in euploid fetuses.

METHODS

 This is a prospective descriptive study with 566 patients at 11 to 14 weeks of gestation. The associations between ultrasound scans and serological variables were studied. For the quantitative variables we used the Spearman test; for the qualitative with quantitative variables the of Mann-Whitney U-test; and for qualitative variables, the X² test was applied. Significance was set at p ≤ 0.05.

RESULTS

 We have found that gestational age has correlation with ductus venosus, nuchal translucency, free fraction of β subunit of human chorionic gonadotropin, pregnancy-associated plasma protein-A and placental growth factor; there is also a correlation between history of miscarriages and nasal bone. Furthermore, we correlated body mass index with nuchal translucency, free fraction of β subunit of human chorionic gonadotropin, and pregnancy-associated plasma protein-A. Maternal age was associated with free fraction of β subunit of human chorionic gonadotropin and pregnancy-associated plasma protein-A.

CONCLUSION

 Our study demonstrates for the first time the behavior of the biochemical and ultrasonographic markers of chromosomopathy screenings during the first trimester in euploid fetuses in Colombia. Our information is consistent with international reference values. Moreover, we have shown the correlation of different variables with maternal characteristics to determine the variables that could help with development of a screening process during the first trimester with high detection rates.

Nasal bone in fetal aneuploidy risk assessment: are they independent markers in the first and second trimesters?

OBJECTIVES

In the mid-trimester ultrasound, nasal bone (NB) length can be used to correct the a priori risk for trisomy 21. Our study aims to evaluate if there is a correlation between an absent NB in the first trimester and a hypoplastic NB in the second trimester.

METHODS

Our two year retrospective analysis of data derived from routine clinical practice. Single euploid fetuses were included. The NB was assessed in both trimesters according to international guidelines and transformed into categorical variables. Logistic regression was performed in order to accomplish our main objective.

RESULTS

From the 759 normal pregnancies included, 45 (5.93%) had abnormal NB in the first trimester and 23 (3%) in the second trimester. Eleven cases (47.8%) of the abnormal NB in the second trimester were abnormal in the 11-14 weeks scan. After the diagnosis of an absent NB in the first trimester the odds ratio (OR) for a hypoplastic NB in the second trimester is 18.926 (7.791-45.977; p-value <0.01).

CONCLUSIONS

Our data suggest a strong association between the NB in the first and in the second trimester in normal euploid fetuses. This is important information to consider when counseling patients on the basis of this ultrasound marker.

Outcome of pregnancies with first-trimester increased nuchal translucency and cystic hygroma in a tertiary maternity hospital in United Arab Emirates

OBJECTIVE

To study the outcome of pregnancies with first-trimester increased nuchal translucency and cystic hygromas.

METHODOLOGY

Retrospective study of 132 pregnancies with first-trimester increased nuchal translucency and cystic hygromas, between January 2015 to December 2018 at Corniche Hospital, Abu Dhabi, UAE. Fetal karyotyping, detailed ultrasound at 18-22 weeks and fetal echocardiography were offered to all women. Adverse outcomes included miscarriage, intrauterine fetal death, termination of pregnancy, neonatal death and structural abnormalities.

RESULTS

Of the 132 pregnancies, 13 had NT > 95th percentile, 89 had NT ≥3 mm and 30 had cystic hygroma. Among 13 pregnancies with NT > 95th centile, 7.6% had abnormal karyotype. Among 89 pregnancies with NT ≥3 mm, 29.2% had abnormal karyotype, 13.4% miscarriage, 7.8% underwent TOP, 5.6% intrauterine fetal death, 1.1% neonatal death and 14.6% had structural abnormalities. Among 30 pregnancies with cystic hygroma, 40% had abnormal karyotype, 20% miscarriage, 13.3% TOP, 13.3% intrauterine fetal death, 6.6% had neonatal death and 20% had structural abnormalities.

CONCLUSION

In our study, karyotype abnormalities increased with increasing nuchal translucency with highest risk in fetuses with cystic hygromas. Increased nuchal translucency was associated with adverse pregnancy outcome, which was higher in the group with NT≥6 mm and cystic hygromas.

The impact of prenatal screening tests on prenatal diagnosis in Taiwan from 2006 to 2019: a regional cohort study

BACKGROUND

The purpose of this study is to evaluate the impact of prenatal screening tests on prenatal diagnosis in Taiwan's 14 years from 2006 to 2019.

METHODS

The prenatal screening methods evolved from the second-trimester serum screening to combined first-trimester screening (cFTS) and then followed by the non-invasive cell-free DNA prenatal test (NIPT). The data used by the Department of Statistics, the Ministry of Health and Welfare and Department of Household Registration, Ministry of the Interior public website.

RESULTS

This regional registry-based cohort retrospective study examined a total of 2,775,792 births from January 2006 to December 2019. The proportion of advanced maternal age (AMA) pregnancies increased from 11.63% in 2006 to 30.94% in 2019. Overall, invasive diagnostic testing was used in 87.22% of AMA pregnancies. The prenatal detection rate of trisomy 21 and 18 increased from 74.1% and 83.3% in 2006 to 96.9% and 98.8% in 2019, respectively.

CONCLUSION

During the second-trimester and cFTS periods, the percentage of AMA pregnancies increased every year and the number of invasive procedures also accompany with increased percentage of AMA. However, during the period that NIPT were implemented, the percentage of invasive procedures decreased.

Execution Analysis of Clarity Locale Segmentation for Condition Recognition Utilizing Genetic Algorithm Method

The collection of fluid at the back of the fetal neck, known as nuchal translucency (NT), is linked to chromosomal abnormalities and early heart failure in the first trimester of pregnancy. Using the Co-Active Adaptive Neuro Fuzzy Inference System (CANFIS) classification algorithm, this research presents an effective way for recognising and localising the NT region in fetus images in which noise removed. Then, pattern features are extracted Initially, the noises in fetus images are detected and eliminated using directional filtering technique and then Gabor transform from the magnitude of Gabor transformed fetus image and then they are optimized using Genetic Algorithm (GA) approach. The extracted GLCM, ELBP and LTP features are integrated into feature vector for further classifications. The size of constructed feature vector is high and leads to high computation time for the classification process. These optimized feature set is classified using CANFIS. Finally, the graph cut segmentation method is used for segmenting the NT region. This proposed method is practically used in many health care centers in rural areas.

What are the ethical issues involved in noninvasive prenatal testing in Japan?

AIMS

Noninvasive prenatal testing (NIPT) of pregnant women has been performed worldwide since 2011, and it is currently performed in more than 90 countries. However, the rate of adoption in Japan remains at less than 2%. This review seeks to identify the ethical and practical issues surrounding noninvasive prenatal screening-including the purpose of the test, its pros and cons, issues surrounding fair treatment, and social factors-to better understand why the adoption rate remains low.

METHODS

This study examines the complex ethical issues surrounding noninvasive prenatal testing, including the purpose of the test, its pros and cons, issues related to fair treatment, and social factors.

RESULTS

Although cell-free DNA analysis for common fetal trisomies using maternal blood is highly accurate, lack of access to such testing and discriminatory attitudes in society remain important barriers. Personal choices such as whether to undergo noninvasive prenatal screening and whether to continue a pregnancy are sometimes criticized by those who believe that it leads to the "selection of life" or discrimination against people with disabilities.

CONCLUSIONS

Obstetrics has changed dramatically in recent years, and prenatal diagnosis technology has also advanced. To keep up with these advances, better information should be provided to ensure the public has a more nuanced understanding of the screening beyond the overused argument that it leads to "selection of life."

Relation Between Increased Fetal Nuchal Translucency Thickness and Chromosomal Defects in Northern Vietnam

Objective To examine the prevalence of all chromosomal defects amongst fetuses with increased nuchal translucency thickness (NT). Methods This is a retrospective study amongst pregnant women indicated for amniocentesis by nuchal translucency above 3.0 mm and consent to the study. A total of 2,720 cases were recruited during the six-year period from 2015 to 2020. All singleton pregnancies were offered fetal karyotype when the fetal nuchal translucency was ≥2.5 mm. The prevalence of chromosomal defects was divided into five NT categories: 2.5-3.4 mm, 3.5-4.4 mm, 4.5-5.4 mm, 5.5-6.4 mm, ≥6.5 mm. Results The study identified 2,720 amniocentesis for increased NT. The mean maternal age was 29.19 (range 17-46) years, and the mean fetal crown-rump length was 66.9 (range 45-84) mm. The fetal karyotype was abnormal in 560 (20.6%) participants. The most frequent chromosomal disorders were trisomy 21 (55%), trisomy 18 (11.2%), trisomy 13 (3.9%), 45,XO (2.7%). The prevalence of chromosomal aberrations was ranged from 17.9% (NT between 2.5-3.4 mm) to 29.7% (NT≥6.5 mm). A majority of fetuses with trisomy 13, 18, or 21 has NT measurement lower than 5.5 mm. In those with Turner syndrome, there was no difference between the group with NT <5.5 mm and the group with NT ≥5.5 mm. Increased maternal age is a risk factor for chromosomal aberrations with the rate increased from 17.6% at the youngest maternal age of 30-34 to 34% at maternal age of 35-39 and to 50% at maternal age of ≥40. Conclusion In fetuses with increased NT, more than a half of the chromosomal abnormalities were affected by defects other than trisomy 21. The distribution of NT was different between Turner syndrome and trisomy 13, 18, 21 syndromes. Women aged 35 years or older had a higher risk of chromosomal aberrations.

Novel Approaches to an Integrated Route for Trisomy 21 Evaluation

Trisomy 21 (T21) is one of the most commonly occurring genetic disorders, caused by the partial or complete triplication of chromosome 21. Despite the significant progress in the diagnostic tools applied for prenatal screening, commonly used methods are still imprecise and involve invasive diagnostic procedures that are related to a maternal risk of miscarriage. In this case, novel prenatal biomarkers are still being evaluated using highly specialized techniques, which could increase the diagnostic usefulness of biochemical prenatal screening for T21. From the other hand, the T21′s pathogenesis, caused by the improper division of genetic material, disrupting many metabolic pathways, could be further evaluated with the use of omics methods, which could result in bringing relevant insights for the evaluation of potential medical targets. Accordingly, a literature search was undertaken to collect novel information about prenatal screening for Down syndrome with the use of advanced technology, with a particular emphasis on the evaluation of novel screening biomarkers and the discovery of potential medical targets. These meta-analyses are focused on novel approaches designed with the use of omics techniques, representing the most rapidly developing and promising field in research today. Considering the limitations and progress of these methods, the use of omics techniques in evaluating T21 pathogenesis could bring beneficial results in prenatal screening, simultaneously uncovering novel potential medical targets.

A survey to assess the incidence of Down syndrome risk in rural southwestern Romania

Despite the significant evolution in recent years in the medical field, many fetal conditions that can be detected in the early stages, remain a social and economic burden due to a lack of diagnostic and treatment programs. The main objective of the present study was to realize a screening program related to the early detection of Down syndrome, by analyzing biochemical and imaging markers, in women from the rural areas of Southwest Romania. Accordingly, data from 269 pregnant women were taken into evaluation for maternal age, maternal weight, smoking and diabetic statuses, along with ultrasound measurements that were performed to establish fetal nuchal translucency (FNT) and biochemical analysis of free β-human chorionic gonadotropin (β-hCG) and pregnancy-associated plasma protein (PAPP-A). Patients at high risk for trisomy 21 (≥1:250) were counseled and the optimal protocol was established for each case. Of the 269 patients studied, 5.6% were included in the risk group based on β-hCG-associated MoM (multiple median approaches) analysis, sonographic measurements and maternal age correlation. Specifically, 60% of patients at risk presented a β-hCG MoM value >1.5 and 20% of patients at risk presented a value ≤0.5 for PAPP-A MoM, and the average maternal age was 33. Measurement of FNT and serum markers, together with associated MoM intervals, was not sufficient to establish the diagnosis of trisomy 21 and to make a risk group inclusion. In summary, the association between sonographic measurements and serum marker values, together with maternal age, are predetermined and indispensable conditions for the most accurate classification in a high-risk group.

Real-time quality control of nuchal translucency measurements using the exponentially weighted moving average chart

OBJECTIVE

The establishment of ongoing audits for first-trimester nuchal translucency (NT) measurements is of paramount importance. The exponentially weighted moving average (EWMA) chart has been published as an efficient tool for NT quality control with the advantages of being suitable for real-time long-term monitoring. This study aimed to assess the efficacy of real-time NT quality control using EWMA charts.

MATERIALS AND METHODS

This was an ongoing prospective study conducted from January 2011 to December 2017 at the Centre for Fetal Medicine Gennet in Prague. The quality of NT measurements was assessed using the NT retrospective distribution parameters and EWMA charts, and the results were presented to the sonographers during collective meetings.

RESULTS

Overall, 28,928 NT measurements obtained from six sonographers were eligible for the study. Looking at individual EWMA charts, we observed four main outcomes. First, there was a clear improvement in the performance of sonographers with initially poor performances. Second, the performance of sonographers with an initially satisfactory quality was maintained. Third, there was an observed deterioration of the performance without the audits. Last, the sonographers appreciated an unequivocal and straightforward graphical presentation of EWMA curves.

CONCLUSION

EWMA proved to be an efficient and suitable tool for real-time monitoring of NT quality and led to an overall improvement of the sonographers' performance.

Ultrasonographic study of umbilical cord twist direction during second trimester

OBJECTIVE

To explore/study/evaluate the relationships among umbilical twist direction, the degree of umbilical twist and differences of umbilical arterial diameters (UAD).

METHODS

All obstetric patients presenting for prenatal care of singleton fetuses between 18 and 25 weeks gestation to a single provider (MN) from 2015 to 2018 had detailed umbilical cord Doppler measurements. Data including the cord twist direction, degree of twist and number of twists per cord segment length, and the diameters of each UA (UAD) and the umbilical vein (UVD) were extracted from the records. UAs were described as right or left depending on their position at the fetal cord insertion. Three groups were identified: Group A: right UAD > left UAD and Group B: left UAD > right UAD Group C: equal UAD. The coiling index was calculated as the inverse of the length of cord required for one complete 360 degrees wrap of the UA around the cord. According to the difference of UADs, the variables of right and left UADs, the coiling index, and frequencies of umbilical twist direction were analyzed using non-parametric methods.

RESULTS

485 singleton fetuses and umbilical cords were examined. The value of the antenatal coiling index in cases with left UAD greater than right was 0.43 ± 0.16, which was significantly higher than 0.38 ± 0.16 with right UAD greater than left (p = .001). There were significant differences between the two groups in the values of right and left UAD, value of right minus left UAD, absolute value between right and left UAD, antenatal coiling index, antenatal coiling index due to umbilical twist direction and frequencies of cord twist direction.

CONCLUSION

The direction of umbilical twist may be in part dependent on differences in diameters of the umbilical arteries, in addition to other fetal characteristics such as fetal movement, or handedness of fetus or mother, fetal hemodynamic forces and structure of muscles of umbilical vessels.

A visual tool inclusive of fetal ultrasound and autopsy findings to reach a balanced approach to counseling on trisomy 18 in early second trimester

Identified by the eponym "Edwards' Syndrome," trisomy 18 (T18) represents the second most common autosomal trisomy after T21. The pathophysiology underlying the extra chromosome 18 is a nondisjunction error, mainly linked with the advanced maternal age. More frequent in female fetuses, the syndrome portends high mortality, reaching a rate of 80% of miscarriages or stillbirths. The three-step evaluation includes first trimester screening for fetal aneuploidy using a combination of maternal age, fetal nuchal translucency thickness, fetal heart rate and maternal serum free ß-hCG and PAPP-A; followed by the research for fragments of fetal DNA in maternal blood; and, finally, invasive techniques leave to the established diagnosis. Starting with the first trimester scan, selected ultrasound findings should be investigated to define not only the impact of the genetic problem on the fetus, but also to address the prenatal counseling. Previous series underline that T18 is not uniformly lethal. An active dialogue on the choices in the management of infants with T18 has emerged, sustained by the transition from the comfort care to the intervention attitude. Survival rates for individuals with supposedly fatal conditions have increased. In this novel scenario, an ad hoc counseling is pivotal. To support it, a comparative analysis by pictorial assays between ultrasound and autopsy findings could be beneficial. We provide an illustrative tool from a clinical case managed in early second trimester, with the purpose to strive a balanced approach in the hard choice faced by couples of fetuses with T18.

Prevalence threshold of screening tests in obstetrics and gynecology

OBJECTIVE

We define the prevalence threshold as the prevalence level below which a test's positive predictive value (PPV) declines most sharply relative to disease prevalence - and thus the rate of false positive results/false discovery rate increases most rapidly. The objective of this study is to determine the prevalence threshold of various screening tests used in obstetrics and gynecology among low-risk women in modern clinical practice.

METHODS

We searched Medline, EMBASE, Google Scholar, Scopus, ISI Web of Science, Cochrane database, and PubMed to obtain the sensitivity and specificity estimates for the following screening tests: 50 g-oral glucose tolerance test (GDM-50 g), non-invasive prenatal testing (NIPT), combined first trimester screening (FTS), vagino-rectal swab for group B streptococcus (GBS) in pregnancy, cervical cytology (Pap) and HPV testing, mammography and manual breast exam, urinary PCR and cervical-vaginal swab testing for gonorrhoea and chlamydia as well as AMH for the diagnosis of PCOS. We used these estimates to calculate disease-specific prevalence thresholds, comparing them to the actual estimates of disease prevalence.

RESULTS

The prevalence thresholds and average estimates of disease prevalence (shown in brackets) are as follows: GDM-50 g 31 % (6%), NIPT 7% (0.2 %), combined FTS 19.5 % (0.2 %), GBS swab 18 % (15-45 %), Pap 21 % (0.2 %), HPV 27 % (0.2 %), mammography 25 % (12.5 %), breast exam 25 % (12.5 %), gonorrhoea -chlamydia 6-13 % (4.2-4.7 %), AMH for PCOS 32 % (10 %).

CONCLUSION

The prevalence thresholds of various screening tests used in obstetrics and gynecology are well above the estimated disease prevalence. This implies that when undertaking population-level screening a significant proportion of positive screening tests obtained are likely false-positives. Attempts at individualizing pre-test probability when undertaking population-level screening are needed in order to best interpret the results of screening tests.

A fetal reduction from twin to singleton based on sonography and cell-free fetal DNA testing: A sequential approach to old pitfalls

OBJECTIVE

We examined the potential value of combining ultrasound and non-invasive prenatal screening (NIPS) of maternal blood to screen for major aneuploidies as an early approach before selective fetal reduction from twin pregnancy to singleton.

STUDY DESIGN

The sample was composed of pregnant women with di-chorionic di-amniotic twins who chose to undergo fetal reduction to singleton at 12-24 weeks of gestation. These women were asked to provide a blood sample for cell-free fetal DNA (cffDNA) testing prior to fetal reduction.

RESULTS

A total of 24 pregnant women with a twin pregnancy prior to fetal reduction to singleton were enrolled. There were 8 cases with structural anomalies (33.3%) in one twin that dictated fetal reduction. The proportion of patients who underwent selective fetal reduction for fetal abnormalities was larger than in several other studies. The NIPS identified 1 case of Trisomy 13 (4.2%). The other 15 cases (62.5%) had no structural or chromosomal anomalies. The decision to undergo elective reduction of twin pregnancy to singleton was made for social reasons or upon the parents' request. Given the 33% of structural anomalies in the cohort, a cost analysis indicated that this procedure was 6.6-fold less expensive (vs. 4.6-fold with 4% structural anomalies in other publications) than conducting invasive procedures for the entire cohort.

CONCLUSION

The findings suggest that an early anatomical scan and cffDNA can increase the overall safety margin and reduce interventional procedures before elective reduction of twin pregnancy to singleton. However, a larger cohort is needed to confirm these results.

First-trimester maternal serum biomarkers and the risk of cerebral palsy

AIM

To investigate whether combined first-trimester screening (cFTS) biomarkers are associated with cerebral palsy (CP) and to identify CP characteristics associated with abnormal biomarker levels.

METHOD

In this retrospective case-control data linkage study, we matched mothers of 435 singletons with CP from a population register to their cFTS records and selected 10 singleton pregnancy controls per case. We compared mean and abnormal levels (expressed as multiples of the median [MoMs]) of pregnancy-associated plasma protein-A (PAPP-A), beta subunit of human chorionic gonadotrophin (β-hCG), and nuchal translucency between cases and controls and between CP subgroups.

RESULTS

Compared with control pregnancies, CP pregnancies had lower mean levels of PAPP-A (0.95 vs 1.01 MoM, p=0.02) and β-hCG (0.93 vs 0.99 MoM, p=0.02). Biomarker levels in CP pregnancies were 1.8 times more likely to be associated with abnormally low levels of PAPP-A (p<0.01), 1.4 times for β-hCG (p=0.12), and 2.6 times for low PAPP-A and β-hCG together (p=0.04). In cases with CP, an abnormally low PAPP-A level was associated with moderate preterm birth, low Apgar scores, and Gross Motor Function Classification System level V. Low β-hCG was associated with very low birthweight.

INTERPRETATION

Low first-trimester biomarker levels suggest a role for early pregnancy factors in some causal pathways to CP.

WHAT THIS PAPER ADDS

Low first-trimester levels of biomarkers in maternal serum are associated with later cerebral palsy (CP). Early pregnancy factors have potential importance in causal pathways to CP. Causal pathways involving preterm birth, term neonatal encephalopathy, and genetic syndromes may be implicated.

Abnormal nuchal translucency followed by normal microarray analysis is associated with placental pathology-related complications

OBJECTIVE

Identify placental pathology-related complications, labor and neonatal outcomes in pregnancies complicated by pathological nuchal translucency (NT) with normal microarray analysis.

METHODS

A retrospective study in which all women with singleton pregnancy who demonstrated NT above 3 mm and a normal microarray analysis were matched to women with normal NT and a normal microarray analysis (2013-2019) in a single tertiary academic center. The following placental pathology-related parameters were measured: preeclampsia, oligohydramnios, suspected intrauterine growth restriction, abnormal Doppler studies or small for gestational age (SGA) neonates. The primary outcome was defined as a composite of complications related to placental pathology including preeclampsia and SGA neonate. Secondary outcomes were labor complications and neonatal morbidity.

RESULTS

A total of 185 women were included in the study: of them, 47 presented an abnormal NT (study group) and 138 presented normal NT (controls). Groups did not significantly differ in baseline characteristics. Regarding primary outcome, all placental-related complications frequencies were higher in the study group, with a composite rate of 17.02% versus 6.52% in controls (p = 0.042%). Secondary outcomes did not differ between groups.

CONCLUSIONS

Abnormal NT measurement presented in pregnancies with normal fetal microarray analysis is associated with higher rates of placental-related complications.

Automatic Fetal Middle Sagittal Plane Detection in Ultrasound Using Generative Adversarial Network

Background and Objective: In the first trimester of pregnancy, fetal growth, and abnormalities can be assessed using the exact middle sagittal plane (MSP) of the fetus. However, the ultrasound (US) image quality and operator experience affect the accuracy. We present an automatic system that enables precise fetal MSP detection from three-dimensional (3D) US and provides an evaluation of its performance using a generative adversarial network (GAN) framework. Method: The neural network is designed as a filter and generates masks to obtain the MSP, learning the features and MSP location in 3D space. Using the proposed image analysis system, a seed point was obtained from 218 first-trimester fetal 3D US volumes using deep learning and the MSP was automatically extracted. Results: The experimental results reveal the feasibility and excellent performance of the proposed approach between the automatically and manually detected MSPs. There was no significant difference between the semi-automatic and automatic systems. Further, the inference time in the automatic system was up to two times faster than the semi-automatic approach. Conclusion: The proposed system offers precise fetal MSP measurements. Therefore, this automatic fetal MSP detection and measurement approach is anticipated to be useful clinically. The proposed system can also be applied to other relevant clinical fields in the future.

Prenatal and perinatal outcomes of twin pregnancy discordant for one fetus with nuchal translucency above the 95th percentile

OBJECTIVE

To compare prenatal and perinatal outcomes of twin pregnancies in which one twin the nuchal translucency (NT) was above the 95th percentile in dichorionic twins (DCT) and monochorionic twins (MCT).

METHOD

In this retrospective study, 93 twin pregnancies (186 fetuses) in which one twin the NT was above the 95th percentile and the co-twin had normal NT were analyzed. Results of of G-banding and Chromosomal microarray (CMA), ultrasound findings and pregnancy outcomes were reviewed.

RESULTS

Totally, 57 pregnancies (114 fetuses) were DCT and 36 pregnancies (72 fetuses) were MCT. Karyotyping and CMA results shown that clinically significant chromosomal abnormalities were found in 16 fetuses, including 13 aneuploidies, 2 chromosomal mosaic and 1 pathological Copy number variations (CNVs) (14 were DCT and 2 were MCT). Overall, the incidence of fetal chromosomal abnormalities was 12.3% (14/114) in DCT and 2.8%(2/72) in MCT (χ² = 3.932, p = 0.047). Among the cases with normal prenatal diagnosis result, structural abnormalities were found in four fetuses (4.0%, 4/100) in DCT and two fetuses (2.9%, 2/70) in MCT (p > 0.999). There were one intrauterine fetal demises (IUFD) and two miscarry in DCT. One IUFD, three subsequently developed Twin-to-Twin Transfusion Syndrome (TTTS) and four developed selective intrauterine growth restriction (sIUGR) in MCT. Totally, the overall fetal survival rate was 85.1% (97/114) in DCT and 80.6% (58/72) in MCT (χ² = 0.653, p = 0.419).

CONCLUSION

Compared to MCT, the incidence of chromosomal abnormalities in DCT discordant for one fetus with NT above the 95th percentile was higher. The risk of structural abnormalities and the rate of fetal survival for both MCT and DCT was similar.

First-trimester screening based on cell-free DNA vs combined screening: A randomized clinical trial on women's experience

OBJECTIVE

To compare women's experience of first-trimester combined screening (FTCS), with women's experience of an approach that uses the combination of a detailed early anatomy scan and cell-free DNA (cfDNA) analysis.

METHODS

This was single-center, open label, parallel group, randomized clinical trial. Pregnant women were randomized at the time of their first prenatal visit to either a policy of first-trimester risk assessment based on FTCS, or to a policy of first-trimester risk assessment based on ultrasound findings and cfDNA. FTCS included ultrasound evaluation with crown-rump length, nuchal translucency (NT) measurement, and a detailed ultrasound scan, along with biochemistry (PAPP-A and free beta hCG). In this group, invasive diagnostic testing was offered to patients with risk >1 in 100, or NT >3.5 mm, or any fetal abnormalities on ultrasound. Women randomized in the intervention group received an approach of first-trimester risk assessment based on ultrasound findings and cfDNA. cfDNA analysis included a simultaneous microarray-based assay of non-polymorphic (chromosomes 13, 18, 21, X and Y) and polymorphic loci to estimate chromosome proportion and fetal fraction. In the intervention group, invasive diagnostic testing was offered to patients with abnormal cfDNA screening results, or NT >3.5 mm, or any fetal abnormalities on ultrasound. Participants received pre-test and post-test questionnaires regarding to measure reassurance, satisfaction, and anxiety. The primary outcome was the post-test reassurance, defined as mean score of reassurance post-test questionnaire. The effect of the assigned screening test on the mean of each outcome was quantified as mean difference (MD) with 95% confidence interval (CI).

RESULTS

Forty women with singleton gestations were enrolled in the trial. Mean score for reassurance was significantly higher in the cfDNA group compared to the FTCS group in the pre-test questionnaire (MD 0.80 points, 95% CI 0.27 to 1.33) and in the post-test questionnaire (MD 16.50 points, 95% CI 2.18 to 30.82). Women randomized to the cfDNA group had higher satisfaction and lower mean anxiety score as assessed in the STAI pre-test questionnaire.

CONCLUSIONS

First-trimester risk assessment for fetal aneuploidy with a combination of a detailed ultrasound examination and cfDNA is associated with better maternal reassurance and better maternal satisfaction compared to the standard first-trimester combined screening with nuchal translucency, and biochemistry.

TRIAL REGISTRATION

Clinicaltrials.gov NCT04077060.

Analysis of copy number variation by sequencing in fetuses with nuchal translucency thickening

Objective

Copy number variation sequencing (CNV‐seq) technique was used to analyze the genetic etiology of fetuses with increased nuchal translucency (NT).

Methods

A total of 139 women with gestational 11‐14 weeks whose fetuses were detected with increased NT (NT ≥ 2.5 mm) in our hospital from July 2016 to December 2018 were selected. Fetal specimens were performed for karyotyping analysis and CNV sequencing.

Results

According to the nuchal translucency thickness, 2.5‐3.4, 3.5‐4.4, 4.5‐5.4, and more than 5.5 mm, the rates of chromosomal abnormalities were 22.8% (13/57), 30.8% (12/39), 42.1% (8/19), and 62.5% (15/24), respectively. There was significant difference among the incidences of chromosomal abnormalities in four groups (χ² = 37.69, P < .01) and the incidences increased with fetal NT thickness. Among 139 cases, there were 36 cases (25.9%) with abnormal chromosome karyotypes. Meanwhile, there were 45 cases (32.3%) with abnormal CNV. In the 12 cases with abnormal CNV and normal chromosome karyotypes, there were 2 cases of pathogenic CNV, 7 cases of CNV with unknown clinical significance, and 3 cases of possibly benign CNV. There was no significant difference in CNV between pregnant women in advanced maternal age and those in normal maternal age (χ² = 1.389, P = .239). In the fetus who showed abnormalities in NT and ultrasonography (χ² = 5.13, P < .05) and the fetus aborted (χ² = 113.19, P < .05), the abnormal rate of CNV was higher with statistically significant difference.

Conclusion

CNV‐seq combined karyotype analysis should be performed simultaneously in fetuses with increased NT, providing a basis for genetic counseling, which is of great significance for prenatal diagnosis.

Cell-free DNA screening for sex chromosome aneuploidies by non-invasive prenatal testing in maternal plasma

BACKGROUND

Non-invasive prenatal testing (NIPT) has been confirmed as the most accurate screening test for trisomies 21, 18, and 13. However, reports on NIPT performance in sex chromosome aneuploidies (SCA) based on real clinical data are still limited.

METHODS

High-throughput massively parallel genomic sequencing (MPS) technique was used to screen for fetal SCAs as part of the research to determine the potential value of NIPT in detecting fetal SCAs in the second trimester. A number of 12,243 consecutive cases from a single center were included in this study.

RESULTS

The positive predictive value (PPV) of NIPT in the present study was 57.6%, which was divided and categorized by individual SCAs as follows: 21.4% for Turner syndrome (45,X), 75.0% for Triple X syndrome (47,XXX), 90.9% for Klinefelter syndrome (47,XXY), and 75.0% for XYY syndrome (47,XYY).

CONCLUSION

The NIPT-based SCA test cannot be used as a diagnostic method, and performing an invasive confirmation test on NIPT-based SCA-positive cases is strongly recommended.

First-trimester screening for fetal growth restriction using Doppler color flow analysis of the uterine artery and serum PAPP-A levels in unselected pregnancies

Purpose: To explore an early diagnostic model for fetal growth restriction (FGR) at 11-13 (+6 days) gestational weeks using Doppler analysis of the uterine artery and measurements of pregnancy-associated plasma protein-A (PAPP-A).Methods: This was a prospective study which included 1796 singleton pregnant women, who received routine pregnancy examination at 11-13 (+6 days) gestational weeks in Shanghai Changning Maternity and Infant Health Hospital between 1 June 2017 and 31 July 2018. Uterine artery pulsatility index (PI), uterine resistance index (RI), and notching were recorded using the Doppler ultrasound detector (Voluson E8; GE Healthcare, Kretztechnik, Zipf, Austria). Maternal serum PAPP-A was assayed using time-resolved fluorescence immunoassay (Perkin-Elmer Life Sciences, Waltham, MA, USA) and analyzed using Fetal Medicine Foundation software. Maternal and neonatal outcomes were followed.Results: Out of 1796 pregnant women aged 18-42 years, 76 (4.2%) mothers had FGR fetus. In the FGR fetuses, the mean uterine artery PI and RI were higher, the PAPP-A levels were 0.42-fold lower (all p values < .05), and notching was 40% higher (p < .0001) than in non-FGR fetuses. The sensitivity and specificity of early diagnosis of FGR and the area under the curve for the combination of uterine artery PI and PAPP-A were 0.788 (95% CI: 0.735, 0.842), 0.816, and 0.758, respectively. A combination of PAPP-A and Doppler analysis of uterine artery was better than individual measurements for predicting FGR (all p values < .05), and the specificity was significantly improved after including serum PAPP-A.Conclusion: The combination of uterine artery PI and PAPP-A measured at 11-13 (+6 days) gestational weeks provides a sensitive and specific predictor for early diagnosis of FGR.

Noninvasive prenatal testing for chromosome aneuploidies and subchromosomal microdeletions/microduplications in a cohort of 42,910 single pregnancies with different clinical features

Background

Since the discovery of cell-free DNA (cfDNA) in maternal plasma, it has opened up new approaches for non-invasive prenatal testing. With the development of whole-genome sequencing, small subchromosomal deletions and duplications could be found by NIPT. This study is to review the efficacy of NIPT as a screening test for aneuploidies and CNVs in 42,910 single pregnancies.

Methods

A total of 42,910 single pregnancies with different clinical features were recruited. The cell-free fetal DNA was directly sequenced. Each of the chromosome aneuploidies and the subchromosomal microdeletions/microduplications of PPV were analyzed.

Results

A total of 534 pregnancies (1.24%) were abnormal results detected by NIPT, and 403 pregnancies had underwent prenatal diagnosis. The positive predictive value (PPV) for trisomy 21(T21), trisomy 18 (T18), trisomy 13 (T13), sex chromosome aneuploidies (SCAs), and other chromosome aneuploidy was 79.23%, 54.84%, 13.79%, 33.04%, and 9.38% respectively. The PPV for CNVs was 28.99%. The PPV for CNVs ≤ 5 Mb is 20.83%, for within 5–10 Mb 50.00%, for > 10 Mb 27.27% respectively. PPVs of NIPT according to pregnancies characteristics are also different.

Conclusion

Our data have potential significance in demonstrating the usefulness of NIPT profiling not only for common whole chromosome aneuploidies but also for CNVs. However, this newest method is still in its infancy for CNVs. There is still a need for clinical validation studies with accurate detection rates and false positive rates in clinical practice.

Current landscape of prenatal genetic screening and testing

Pregnant patients should be offered the option of prenatal genetic screening and diagnostic testing. The type of screening and testing offered to a patient may depend on various factors including but not limited to age, family history, fetal findings, exposures, and patient preferences. Prenatal screening is available for a variety of genetic conditions including aneuploidy, congenital abnormalities, and carrier status. Diagnostic testing options include karyotype, prenatal microarray, as well as next-generation sequencing. The various options differ in methodology, accuracy, timing and indication for testing, and information they provide. Given that the technologies related to prenatal testing are rapidly evolving and improving, the array of available screening and testing modalities are increasing. This article reviews the current offerings in prenatal screening and diagnosis.

Result of Prospective Validation of the Trisomy Test® for the Detection of Chromosomal Trisomies

Noninvasive prenatal testing (NIPT) is one of the most common prenatal screening tests used worldwide. Trisomy Test® belongs to NIPT tests based on low-coverage whole-genome sequencing. In our prospective study, 7279 samples of pregnant women collected during approximately two years were analyzed. In this cohort, 117 positive cases for trisomies 21, 18, and 13 were reported. An in-house designed bioinformatic pipeline and proprietary biostatistical approach was used for the detection of trisomies. The pooled sensitivity and specificity of our test reached 99.12% and 99.94%, respectively. The proportion of repeatedly uninformative results after repeated blood draws was 1.11%. Based on the presented results, we can confirm that the Trisomy Test® is fully comparable with other commercial NIPT tests available worldwide.

Screening performance of congenital heart defects in first trimester using simple cardiac scan, nuchal translucency, abnormal ductus venosus blood flow and tricuspid regurgitation

OBJECTIVE

The objective of this study was to analyze if the addition of simple cardiac scan in cases with increased nuchal translucency (NT) and/or abnormal ductus venosus (DV) blood flow, and/or tricuspid regurgitation (TCR) can improve detection of congenital heart defects (CHD) in chromosomally normal fetuses without non-cardiac defects at 11-13 + 6 gestational weeks in a population of singleton pregnancies.

METHODS

During the 10 years period, all singleton pregnancies at 11-13 + 6 weeks were routinely scanned for NT, DV blood flow and TCR assessment and, if a single of these parameters was abnormal, simple cardiac scan with 2D gray scale and color and/or directional power Doppler in 4-chamber (4-CV) and 3 vessel and trachea views (3VTV) was performed.

RESULTS

The sensitivity and specificity of NT ≥ 95th + DV R/A a-wave + TCR in detecting CHD were 77% and 97%, respectively, and of simple cardiac scan, 67% and 98%, respectively. Area under the curve of receiver operating characteristic curve of NT ≥ 95th + DV R/A a-wave + TCR was 0.838, and of NT ≥ 95th + DV R/A a-wave + TCR + simple cardiac scan was 0.915.

CONCLUSIONS

In chromosomally normal fetuses without non-cardiac anomalies, addition of simple cardiac scan to the combined first trimester screening parameters improves detection of major CHD during first trimester.

Pregnancy outcome in foetuses with increased nuchal translucency - 10-years' experience in a prenatal medical practice

This retrospective study describes pregnancy outcome for foetuses with increased nuchal translucency (NT) in relation to the degree of increase in a local specialised medical practice. Data from 7352 first trimester pregnancies examined by a single observer between 10/07 and 07/17 were screened. Three hundred and ninety-three foetuses (5.3%) that had an increased NT ≥ 95th percentile and available pregnancy outcome were identified. For this population, the frequencies of chromosomal abnormality, foetal malformation, intrauterine death (IUD) and termination of pregnancy (TOP) were determined in relation to the degree of NT thickness. Favourable pregnancy outcome decreased from 77.8% (lowest NT group, 95th percentile-3.5 mm) to 5% (highest NT ≥ 6.5 mm), whereas chromosomal abnormalities rose from 18.1% to 70%. An abnormal karyotype occurred in 39.2% of foetuses with increased NT. In euploid foetuses, cardiac defects were the most common structural abnormalities. The data largely matches with earlier studies conducted in large hospital-based settings. However, a rather high proportion of foetuses with abnormal karyotype was observed.IMPACT STATEMENTWhat is already known on this subject? Increased NT is associated with chromosomal abnormalities as well as an adverse perinatal outcome also in foetuses with a normal karyotype. The prevalence of an adverse outcome increases with NT thickness. These studies were conducted more than 10 years ago mainly in academic settings.What do the results of this study add? This study describes pregnancy outcome of a population of foetuses with increased NT that were examined in a medical practice by a single observer over a period of 10 years with state of the art ultrasound equipment. We observed a relatively large proportion of foetuses with abnormal karyotype. In euploid foetuses, increased NT was associated with a wide range of foetal malformations and genetic syndromes.What are the implications of these findings for clinical practice and/or further research? Even mildly increased NT thickness is associated with an adverse pregnancy outcome, underlining the importance of thorough ultrasound examinations. Specialised prenatal medical practices can provide state-of the art technology and provide improve parental counselling.

Increased nuchal translucency and pregnancy outcomes: experience of Başkent University Ankara Hospital

Objective:

First trimester nuchal translucency (NT) measurement is considered to be an important tool in antenatal follow-up. This study aimed to evaluate the outcomes of pregnancies with increased NT at Başkent University Ankara Hospital between 2004 and 2016.

Materials and Methods:

Patients with NT measurements ≥1.5 multiples of median (MoM) were divided into two groups; group I included increased NT cases without fetal anomalies (either abnormal fetal karyotype or congenital structural anomalies) or loss (intrauterine fetal death), and group II included increased NT cases with fetal anomalies or loss. The groups were compared with each other with respect to maternal demographic features and NT measurements.

Results:

Karyotype analyses were normal in 73.1% of cases with increased NT (57/78). Among those, 21.1% (12/57) had structural anomalies, and to specify, 9.6% (5/52 over 18 weeks) had cardiac anomalies. Although maternal demographic features did not differ significantly, NT measurements, both as millimeters and MoM, were significantly higher in group II (p<0.05). According to the receiver operating characteristic (ROC) curves, the optimal cut-off values for NT measurements for predicting fetal anomalies or loss were 3.05 mm and 2.02 MoM. NT measurement >7 millimeters or NT MoM >4.27 resulted in poor fetal outcomes without exception.

Conclusion:

Higher NT measurements indicate poorer pregnancy outcomes. Our study indicates that fetal echocardiography must be considered for all cases with increased NT.