EARLY DETECTION OF EMBRYONIC MALFORMATIONS BY TRANSVAGINAL AND COLOR DOPPLER SONOGRAPHY

A total of 834 women with uneventful pregnancies were followed prospec tively until the 15th week of gestation by TVS to screen for early emb ryonic malformations. Twenty-eight embryonic anomalies were detected i n this series (3.3%). The median gestational age at diagnosis was 11 ( range, 8 to 15) weeks. Two neural tube defects were missed by early TV S screening. Two suspected abdominal wall defects were not confirmed b y repeat mid-second trimester abdominal sonography representing 6.7% o f all fetal malformations evident by 24 weeks of gestation. The sensit ivity and specificity of TVS screening for fetal malformations in this series were 93.3 and 99.7%, respectively. In addition, the role of TC DU also was investigated in these 28 abnormal embryos. TCDU proved to be of limited value as it was useful only for evaluating those embryon ic malformations with vascular involvement. In such cases, the diagnos is was greatly enhanced with this technique. Two previously undetected single umbilical arteries were also diagnosed by TCDU as well. This s eries included 11 aneuploid embryos (44%), most of them among the embr yos with focal or generalized edema. This study demonstrates that scre ening for early embryonic malformations is feasible using TVS techniqu es, but a repeat mid-second trimester abdominal sonogram still is reco mmended.