First-Trimester Screening of Open Neural Tube Defects Using Biometrics and Maternal Serum Markers

Open neural tube defects are congenital malformations associated with significant morbidity. Early detection during the first trimester remains a key challenge. This retrospective monocentric study aims to evaluate the diagnostic performance of fetal biometrics (biparietal diameter and abdominal transverse diameter ratios) and maternal serum markers (beta-hCG and PAPP-A) for early screening of open neural tube defects. The study will assess the predictive value of these parameters individually and in combination to define optimal screening thresholds applicable in routine clinical practice

Inclusion Criteria: * Adult pregnant woman (≥18 years) * First-trimester ultrasound performed at Strasbourg University Hospitals between 01/01/2011 and 31/12/2023 * No written opposition to reuse of medical data for research purposes Exclusion Criteria: * Written opposition to reuse of medical data for research purposes * Multiple pregnancy * Presence of fetal growth abnormality, morphological or genetic anomaly during pregnancy * Crown-rump length \84 mm at screening ultrasound * Missing data * Fetus with closed dysraphism