Diagnosis of Fetal Structural Anomalies at 11 to 14 Weeks.

Objectives: To assess the performance of first‐trimester ultrasound (US) in identifying major fetal structural abnormalities in an unselected population. Methods: We conducted a retrospective analysis of all pregnancies that underwent the 11‐ to 14‐week scan in the Fetal Medicine Department of Filantropia Hospital in Bucharest, which were prospectively examined within our screening program. The purpose of the first‐trimester US was to evaluate the risk for chromosomal abnormalities and to conduct fetal anatomic examination using a detailed protocol. Results: Our population consisted of 7480 pregnant patients (7576 fetuses). The follow‐up was completed for 6045 patients (6114 fetuses). The prevalence of major structural anomalies was 1.89%. In the first trimester, we identified 79% of all major structural anomalies. The highest detection rates were achieved for abdominal wall defects (100%), major central nervous system anomalies (88%), cardiac defects (74%), and skeletal anomalies (71%). The nuchal translucency was increased in 35% of the cases with structural anomalies, and 95% of these were diagnosed in the first trimester. Seventy percent of the patients who presented with structural anomalies and a normal nuchal translucency were diagnosed in the first trimester. Conclusions: Our results emphasize the importance of performing a detailed US examination at 11 to 14 weeks' gestation in identification of fetal structural defects. [ABSTRACT FROM AUTHOR]