Is first trimester screening an opportunity for early diagnosis of structural anomalies?: A retrospective cohort study

Abstract

Objective: To share our experience of ultrasonographic evaluation of fetal anatomy in the first trimester and pregnancy follow-up in a tertiary center. Material and Methods: This retrospective study was conducted in the Ac & imath;badem University Atakent Hospital and Ac & imath;badem University Bak & imath;rk & ouml;y Hospital Prenatal Diagnosis Units between April 2015 and December 2019. The study group included pregnant women referred for first-trimester aneuploidy screening and anomaly survey. Results: The mean maternal age was 31.28 +/- 4.43 years and ranged from 20-49 years. The median gestational week at which first-trimester evaluation was made was 12.4 weeks. Of 3254 cases, 55 (1.69%) had pathologic ultrasound findings in the first-trimester anomaly scan, including increased nuchal translucency (NT) value over 95th percentile in 34 fetuses (52.3%) with structural anomaly. Median (range) crown-rump length was 58.69 (45-83) mm, and the median NT value was 3,5 (1.5-12) mm for fetuses with abnormal sonographic findings. The total detection rate for sonographic anomalies in the first-trimester scan was 60.43%. Of note, 27.3% of fetuses with detected anomalies had multiple congenital anomalies. Twenty-four new cases were diagnosed in the second trimester, and 11 new cases were detected in the last trimester from the same cohort. Conclusion: Screening between 11-14 weeks of pregnancy may be an opportunity to evaluate maternal health and detect severe fetal anomalies. The family should be counselled about structural anomalies that may be detected later, especially in the second and third trimesters, the limitations of the technique, and the ongoing progress of fetal development.