Prenatal screening in the era of non-invasive prenatal testing: a Nationwide cross-sectional survey of obstetrician knowledge, attitudes and clinical practice.

backgroundNon-invasive prenatal testing (NIPT) has revolutionized the prenatal screening landscape with its high accuracy and low false positive rate for detecting Trisomy 21, 18 and 13. Good understanding of its benefits and limitations is crucial for obstetricians to provide effective counselling and make informed decisions about its use. This study aimed to evaluate obstetrician knowledge and attitudes regarding NIPT for screening for the common trisomies, explore how obstetricians integrated NIPT into first-line and contingent screening, and determine whether expanded use of NIPT to screen for sex chromosome aneuploidies (SCAs) and microdeletion/microduplication syndromes (CNVs) was widespread.

methodsA questionnaire was designed and administered with reference to the CHERRIES criteria for online surveys. Doctors on the Obstetrics & Gynaecology trainee and specialist registers were invited to participate. Medians and 95% confidence intervals (CI) were reported for confidence and knowledge scores.

results94/306 (30.7%) doctors responded to the survey. First trimester screening (FTS) remained the main method offered to screen for the common trisomies. 45.7% (43/94) offered NIPT as an alternative first-line screen for singletons and 30.9% (29/94) for monochorionic diamniotic twins. A significant proportion offered concurrent NT and NIPT (25/94, 26.6%), or FTS and NIPT (33/94, 35.1%) in singletons. Varying follow up strategies were offered at intermediate, high and very-high FTS risk cut-offs for Trisomy 21. Respondents were likely to offer screening for SCAs and CNVs to give patients autonomy of choice (53/94, 56.4% SCAs, 47/94, 50% CNVs) at no additional cost (52/94, 55.3% SCAs, 39/94, 41.5% CNVs). Median clinical knowledge scores were high (10/12) and did not differ significantly between specialists (95% CI 10-11) and non-specialists (95% CI 9.89-11). Lower scores were observed for scenarios in which NIPT would be more likely to fail.

conclusionsOur findings show the diversity of clinical practice with regard to the incorporation of NIPT into prenatal screening algorithms, and suggest that the use of NIPT both as a first-line screening tool in the general obstetric population, and to screen for SCAs and CNVs, is becoming increasingly prevalent. Clear guidance and continuing educational support are essential for providers in this rapidly evolving field.