Maternal attitude towards first trimester screening for fetal abnormalities

Detection of non-cardiac fetal abnormalities on ultrasound at 11-14 weeks: systematic review and meta-analysis

OBJECTIVES

To assess the diagnostic accuracy of two-dimensional ultrasound at 11-14 weeks' gestation as a screening test for individual fetal anomalies and to identify factors impacting on screening performance.

METHODS

This was a systematic review and meta-analysis that was developed and registered with PROSPERO (CRD42018111781). MEDLINE, EMBASE, Web of Science Core Collection and the Cochrane Library were searched for studies evaluating the diagnostic accuracy of screening for 16 predefined, non-cardiac, congenital anomalies considered to be of interest to the early anomaly scan. We included prospective and retrospective studies from any healthcare setting conducted in low-risk, mixed-risk and unselected populations. The reference standard was the detection of an anomaly on postnatal or postmortem examination. Data were extracted to populate 2 × 2 tables and a random-effects model was used to determine the diagnostic accuracy of screening for the predefined anomalies (individually and as a composite). Secondary analyses were performed to determine the impact on detection rates of imaging protocol, type of ultrasound modality, publication year and index of sonographer suspicion at the time of scanning. Post-hoc secondary analysis was conducted to assess performance among studies published during or after 2010. Risk of bias assessment and quality assessment were undertaken for included studies using the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

From 5684 citations, 202 papers underwent full-text review, resulting in the inclusion of 52 studies comprising 527 837 fetuses, of which 2399 were affected by one or more of the 16 predefined anomalies. Individual anomalies were not equally amenable to detection on first-trimester ultrasound: a high (> 80%) detection rate was reported for severe conditions, including acrania (98%), gastroschisis (96%), exomphalos (95%) and holoprosencephaly (88%); the detection rate was lower for open spina bifida (69%), lower urinary tract obstruction (66%), lethal skeletal dysplasias (57%) and limb-reduction defects (50%); and the detection rate was below 50% for facial clefts (43%), polydactyly (40%) and congenital diaphragmatic hernia (38%). Conditions with a low (< 30%) detection rate included bilateral renal agenesis (25%), closed spina bifida (21%), isolated cleft lip (14%) and talipes (11%). Specificity was > 99% for all anomalies. Secondary analysis showed that detection improved with advancing publication year, and that the use of imaging protocols had a statistically significant impact on screening performance (P < 0.0001).

CONCLUSIONS

The accurate detection of congenital anomalies using first-trimester ultrasound is feasible, although detection rates and false-positive rates depend on the type of anomaly. The use of a standardized protocol allows for diagnostic performance to be maximized, particularly for the detection of spina bifida, facial clefts and limb-reduction defects. Highlighting the types of anomalies amenable to diagnosis and determining factors enhancing screening performance can support the development of first-trimester anomaly screening programs. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Clinical implementation of first trimester screening for congenital heart defects

OBJECTIVE

To examine the feasibility and performance of implementing a standardized fetal cardiac scan at the time of a routine first-trimester ultrasound scan.

METHOD

A retrospective, single-center study in an unselected population between March 2021 and July 2022. A standardized cardiac scan protocol consisting of a four-chamber and 3-vessel trachea view with color Doppler was implemented as part of the routine first-trimester scan. Sonographers were asked to categorize the fetal heart anatomy. Data were stratified into two groups based on the possibility of evaluating the fetal heart. The influence of maternal and fetal characteristics and the detection of major congenital heart disease were investigated.

RESULTS

A total of 5083 fetuses were included. The fetal heart evaluation was completed in 84.9%. The proportion of successful scans increased throughout the study period from 76% in the first month to 92% in the last month. High maternal body mass index and early gestational age at scan significantly decreased the feasibility. The first-trimester detection of major congenital heart defects was 7/16, of which four cases were identified by the cardiac scan protocol with no false-positive cases.

CONCLUSION

First-trimester evaluation of the fetal heart by a standardized scan protocol is feasible to implement in daily practice. It can contribute to the earlier detection of congenital heart defects at a very low false positive rate.

First-Trimester Ultrasound Screening in Routine Obstetric Practice

Technologic advances and ultrasonographer-physician experience in fetal imaging have led to significant improvements in our ability to distinguish between normal and abnormal fetal structural development in the latter part of the first trimester. As a critical component of pregnancy care, assessment of fetal anatomy at the end of the first trimester with a standardized imaging protocol should be offered to all pregnant patients regardless of aneuploidy screening results because it has been demonstrated to identify approximately half of fetal structural malformations. Early identification of abnormalities allows focused genetic counseling, timely diagnostic testing, and subspecialist consultation. In addition, a normal ultrasound examination result offers some degree of reassurance to most patients. Use of cell-free DNA alone for aneuploidy screening while foregoing an accompanying early anatomic evaluation of the fetus will result in many anomalies that are typically detected in the first trimester not being identified until later in pregnancy, thus potentially diminishing the quality of obstetric care for pregnant individuals and possibly limiting their reproductive options, including pregnancy termination.

Exploring measurement tools used to assess knowledge, attitudes, and perceptions of pregnant women toward prenatal screening: A systematic review

There is a lack of standardized measurement tools globally to assess knowledge, attitudes, and perceptions of expecting women toward prenatal screening. The purpose of this systematic review was to identify reasons women pursue or decline prenatal screening and compare the strengths and limitations of available measurement tools used to assess pregnant women's perceptions, knowledge, and attitudes toward prenatal screening. This review followed the five-step York methodology by Arksey and O'Malley and incorporated recommendations from the Preferred Reporting Items for Systematic Reviews and Meta-Analysis checklist for the extraction, analysis, and presentation of results. The five steps consisted of: (1) identification of the research questions; (2) searching for relevant studies; (3) selection of studies relevant to the research questions; (4) data charting; and (5) collation, summarization, and reporting of results. Four online databases (PubMed, Embase, Web of Science, and Cochrane Library) were selected after the librarian's development of a detailed search strategy. The Rayyan platform was used between June 2023 and August 2023 to epitomize the articles produced from our search. A total of 68 eligible studies were included in the analysis. The top five major reasons for declining prenatal screening uptake included (1) being unsure of the risk of prenatal screening and harm to the baby or miscarriage (n = 15), (2) not considering action such as termination of pregnancy for prenatal screening to be considered as necessary (n = 14), (3) high cost (n = 12), (4) lack of knowledge about testing procedures and being anxious about the test (n = 10), and (5) being worried about probability of false negative or false positive results (n = 6). Only 32 studies utilized scientifically validated instruments. Difficulties in capturing representative, adequately sized samples inclusive of diverse ethnicities and demographics were pervasive. Findings highlight the need for rigorous validation of research measurement methodologies to ensure the accuracy and applicability of resulting data regarding the assessment of prenatal screening perceptions, knowledge, and attitudes across diverse female populations.Registration: N/A.

Timing of diagnosis of fetal structural abnormalities after the introduction of universal cell-free DNA in the absence of first-trimester anatomical screening

Introduction

Since 2021, first‐trimester anatomical screening (FTAS) is offered in the Netherlands alongside genome‐wide cell‐free DNA (cfDNA). Previously, only second‐trimester anatomical screening (STAS) was offered. This study identifies structural abnormalities amenable to first‐trimester diagnosis detected at/after STAS in the period following cfDNA implementation and preceding FTAS introduction.

Methods

This retrospective cohort includes 547 fetuses referred between 2017 and 2020 because of suspected structural abnormalities before/at/after STAS. Additional prenatal investigations and postnatal follow‐up were searched. Abnormalities were classified into “always”, “sometimes”, and “never” detectable in the first‐trimester based on a previously suggested classification.

Results

Of the 547 pregnancies, 13 (2.6%) received FTAS and 534 (97.6%) received a dating ultrasound and STAS. In 492/534 (92.1%) anomalies were confirmed; 66 (13.4%) belonged to the “always detectable” group in the first trimester, 303 (61.6%) to the “sometimes detectable”, and 123 (25.0%) to the never detectable. Of the “always detectable” anomalies 29/66 (44%) were diagnosed during dating ultrasounds and 37 (56%) during STAS. The rate of termination of pregnancy for anomalies detected during FTAS and at/after STAS was 84.6% (n = 11/13) and 29.3% (n = 144/492) (p < 0.01).

Conclusion

When FTAS is not part of screening paradigms, most fetal anomalies remain undetected until the second trimester or later in pregnancy, including 56% of anomalies “always detectable” in the first trimester.

What's already known about this topic?

About one‐third of all prenatally detectable fetal congenital abnormalities can be diagnosed in the first trimester of pregnancy. Especially major and lethal defects are amenable to early diagnosis.

What does this study add?

This study shows the evident delay in the timing of diagnosis of fetal structural abnormalities when first‐trimester anatomical screening (FTAS) is not routinely offered. The findings of this study strongly support the implementation of a regulated FTAS program in addition to universal screening by cell‐free DNA.

Psychological outcomes, knowledge and preferences of pregnant women on first-trimester screening for fetal structural abnormalities: A prospective cohort study

INTRODUCTION

The primary aim of this study is to investigate the impact of a 13-week anomaly scan on the experienced levels of maternal anxiety and well-being. Secondly, to explore women's knowledge on the possibilities and limitations of the scan and the preferred timing of screening for structural abnormalities.

MATERIAL AND METHODS

In a prospective-cohort study conducted between 2013-2015, pregnant women in the North-Netherlands underwent a 13-week anomaly scan. Four online-questionnaires (Q1, Q2, Q3 and Q4) were completed before and after the 13- and the 20-week anomaly scans. In total, 1512 women consented to participate in the study and 1118 (74%) completed the questionnaires at Q1, 941 (64%) at Q2, 807 (55%) at Q3 and 535 (37%) at Q4. Psychological outcomes were measured by the state-trait inventory-scale (STAI), the patient's positive-negative affect (PANAS) and ad-hoc designed questionnaires.

RESULTS

Nine-nine percent of women wished to be informed as early as possible in pregnancy about the absence/presence of structural abnormalities. In 87% of women levels of knowledge on the goals and limitations of the 13-week anomaly scan were moderate-to-high. In women with a normal 13-week scan result, anxiety levels decreased (P < .001) and well-being increased over time (P < .001). In women with false-positive results (n = 26), anxiety levels initially increased (STAI-Q1: 39.8 vs. STAI-Q2: 48.6, P = 0.025), but later decreased around the 20-week anomaly scan (STAI-Q3: 36.4 vs. STAI-Q4: 34.2, P = 0.36).

CONCLUSIONS

The 13-week scan did not negatively impact the psychological well-being of pregnant women. The small number of women with screen-positive results temporarily experienced higher anxiety after the scan but, in false-positive cases, anxiety levels normalized again when the abnormality was not confirmed at follow-up scans. Finally, most pregnant women have moderate-to-high levels of knowledge and strongly prefer early screening for fetal structural abnormalities.

Relationship between first trimester nuchal septations and chromosomal anomalies

OBJECTIVES

This study aimed to evaluate the association of nuchal septations with chromosomal anomalies during the first trimester of pregnancy.

METHODS

A total of 281 patients who were diagnosed to have elevated nuchal translucency (NT > 3 mm) or nuchal septations during the first trimester from Jan. 2014 to Dec. 2016 were included. These patients were divided into three groups: 1) patients with NT thickness between 3 and 5 mm and without nuchal septations (NT 3-5 mm group, n = 124), 2) patients with NT thickness > 5 mm and without nuchal septations (NT > 5 mm group, n = 96), and 3) patients with nuchal septations (NS group, n = 61).

RESULTS

The rate of chromosomal abnormalities was significantly higher for patients in NS group compared to those in the NT 3-5 mm group (P < .01) and NT > 5 mm group (P < .01). After controlling for maternal age, maternal BMI, ethnicity and crown-rump length, nuchal septations were reported to be significantly associated with a higher risk of chromosomal anomalies compared with NT 3-5 mm (OR = 4.97; 95% CI: 2.76-10.77; P < .01) and NT > 5 mm (OR = 3.82; 95% CI: 1.87-7.21; P < .01) (P < .01).

CONCLUSIONS

Measurement of nuchal septations during the first trimester of pregnancy proves to be a useful ultrasound prognostic indicator of chromosomal anomalies.

Detection of structural abnormalities in fetuses with normal karyotype at 11-13 weeks using the anatomic examination protocol of the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG)

Objective: To assess the performance of sonography in the detection of fetal nonchromosomal abnormalities using a standard anatomic examination protocol proposed by International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) at 11⁺⁰-13⁺⁶ weeks.Materials and methods: A prospective observational study was conducted between June 2013-May 2017 in singleton pregnancies attending for a routine scan at 11⁺⁰-13⁺⁶ weeks. All examinations were performed by maternal-fetal medicine specialists certified by the Fetal Medicine Foundation according to the anatomic examination protocol described in the ISUOG guidelines. First-trimester findings were compared to those of the anomaly scan at 20⁺⁰-23⁺⁶ weeks and the postnatal examination. The primary outcome was the detection rate of major structural abnormalities in fetuses with normal karyotype at 11⁺⁰-13⁺⁶ weeks.Results: After excluding 17 chromosomal abnormalities, major fetal structural defects were detected in 57 (1.7%) of the remaining 3361 cases. Of these, 27 (47.3%) were detected at 11⁺⁰-13⁺⁶ weeks, including all cases of acrania (4), exomphalos (4), megacystis (2) and body stalk anomaly (2). Furthermore, there was a first-trimester diagnosis in 36.4% (4/11) of major cardiac defects, 38% (6/16) of limb defects, and 100% (2/2) of facial clefts.Discussion: Targeted ultrasound examination may identify all the so called "always" detectable major abnormalities and a significant proportion of the "sometimes", detectable at 11⁺⁰-13⁺⁶ weeks.

Trisomy 21 screening based on first and second trimester in a Taiwanese population

OBJECTIVE

This study investigates the performance of first- and second-trimester screening tests for detecting fetal trisomy 21 in a Taiwanese population.

MATERIALS AND METHODS

This multicenter study 29,137 cases enrolled the chromosomal abnormality screening between 2013 and 2014 two years period from Taipei city. There were 23,990 was done the first trimester screening using a combination of fetal nuchal translucency, maternal serum β-human chorionic gonadotropin, and pregnancy-associated plasma protein-A between 11⁺⁰ and 13⁺⁶ weeks of gestation age. Second-trimester screening was done for 5149 cases using a double test (β-human chorionic gonadotropin and serum alpha fetoprotein) between 15 and 20 weeks of gestation. The cut-off risk for both is 1:270 or higher.

RESULTS

This multicenter study 29,137 cases that completed first- and second-trimester screening, and the outcome was available in 28,726 cases. The mean maternal age of the screen-positive group was 34.6 ± 4.2 years. The first-trimester had 891 cases screening positive with a detection rate of 97.5% for fetal trisomy 21, and false positive rate of 3.5%. In the second-trimester had 334 cases screening positive, the detection rate and false positive rate were 33.3% and 6.4% for trisomy 21, respectively.

CONCLUSION

The first-trimester screening had higher performance with a lower false positive rate than the second-trimester screening. First-trimester screening could reduce the rate of unnecessary invasive testing for all pregnant women.

Early Detection of Structural Anomalies in a Primary Care Setting in the Netherlands

OBJECTIVE

This study assessed the percentage and type of congenital anomalies diagnosed at first-trimester ultrasound (US) scan in a primary care setting without following a standardized protocol for fetal anatomical assessment.

MATERIALS AND METHODS

US scans performed between 11+0 and 13+6 weeks of gestation in pregnancies with estimated date of delivery between January 1, 2012 and January 1, 2016 were searched. Data were supplemented with results of 20-week scans and pregnancy outcome.

RESULTS

Of all scans, 38.6% were dating scans and 61.4% were part of first-trimester screening. Anomalies were diagnosed prenatally in 200 (1.8%) fetuses; 81 (0.7%) were chromosomal and 119 (1.1%) were structural. Of all prenatally detected anomalies, 27% (n = 32) were detected at first-trimester scan, with a false-positive rate of 0.04%. All cases of anencephaly (n = 4), encephalocele (n = 2), exomphalos (n = 9), megacystis (n = 4), and limb reduction (n = 1) were diagnosed. First-trimester detection of gastroschisis and congenital heart defects was 67 and 19%, respectively.

CONCLUSION

In a primary care setting, global fetal anatomical assessment at first-trimester scan without following a standardized protocol detects about 30% of all structural anomalies and most of the severe anomalies, with an extremely low false-positive rate. We hypothesize that additional training and use of a systematic protocol would improve early detection of structural anomalies.

Effectiveness of 12-13-week scan for early diagnosis of fetal congenital anomalies in the cell-free DNA era

OBJECTIVES

The main aim of this study was to assess the proportion and type of congenital anomalies, both structural and chromosomal, that can be detected at an early scan performed at 12-13 weeks' gestation, compared with at the 20-week structural anomaly scan offered under the present screening policy. Secondary aims were to evaluate the incidence of false-positive findings and ultrasound markers at both scans, and parental choice regarding termination of pregnancy (TOP).

METHODS

Sonographers accredited for nuchal translucency (NT) measurement were asked to participate in the study after undergoing additional training to improve their skills in late first-trimester fetal anatomy examination. The early scans were performed according to a structured protocol, in six ultrasound practices and two referral centers in the north-east of The Netherlands. All women opting for the combined test (CT) or with an increased a-priori risk of fetal anomalies were offered a scan at 12-13 weeks' gestation (study group). All women with a continuing pregnancy were offered, as part of the 'usual care', a 20-week anomaly scan.

RESULTS

The study group consisted of 5237 women opting for the CT and 297 women with an increased a-priori risk of anomalies (total, 5534). In total, 51 structural and 34 chromosomal anomalies were detected prenatally in the study population, and 18 additional structural anomalies were detected after birth. Overall, 54/85 (63.5%) anomalies were detected at the early scan (23/51 (45.1%) structural and all chromosomal anomalies presenting with either an increased risk at first-trimester screening or structural anomalies (31/34)). All particularly severe anomalies were detected at the early scan (all cases of neural tube defect, omphalocele, megacystis, and multiple severe congenital and severe skeletal anomalies). NT was increased in 12/23 (52.2%) cases of structural anomaly detected at the early scan. Of the 12 cases of heart defects, four (33.3%) were detected at the early scan, five (41.7%) at the 20-week scan and three (25.0%) after birth. False-positive diagnoses at the early scan and at the 20-week scan occurred in 0.1% and 0.6% of cases, respectively, whereas ultrasound markers were detected in 1.4% and 3.0% of cases, respectively. After first- or second-trimester diagnosis of an anomaly, parents elected TOP in 83.3% and 25.8% of cases, respectively.

CONCLUSIONS

An early scan performed at 12-13 weeks' gestation by a competent sonographer can detect about half of the prenatally detectable structural anomalies and 100% of those expected to be detected at this stage. Particularly severe anomalies, often causing parents to choose TOP, are amenable to early diagnosis. The early scan is an essential part of modern pregnancy care. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Do pregnant women want to know the sex of the expected child at routine ultrasound and are they interested in sex selection?

BACKGROUND

The aim of the study was to investigate if expecting parents wanted to know the sex of the fetus during ultrasound examination and if they had discussed it with the midwife. Another aim was to explore any interest in sex selection.

METHODS

A longitudinal survey in early and late pregnancy among 2393 women in Sweden.

RESULTS

Almost all (95.8%, n = 2289) women had discussed sex determination with the partner before the ultrasound scan, and 57% (n = 1356) of women and their partners wanted to find out the fetal sex. The expecting parents mostly initiated a discussion with the midwife (46%, n = 1088), but 10% (n = 229) stated that the midwives initiated the discussion. Few (5%, n = 118) expressed a potential interest in selecting sex of a baby. Women who were interested in sex determination did not differ from those who were not, with respect to age, origin, education, parity, level of pregnancy planning, or importance of religion, but women who had chosen another fetal diagnostic method were more interested in sex determination and in potential sex selection.

CONCLUSIONS

Half of women and their partners wanted to know the fetal sex, and 5% were interested in sex selection. This high interest in sex determination is a challenge, since present national guidelines do not include sex determination as an option.