[Examination of fetal developmental abnormalities by routine transvaginal ultrasonic screening in the 12th week of pregnancy].

The increased resolution of transvaginal sonography allows a detailed evaluation of fetal anatomy in the first trimester of pregnancy. According to the authors experiences screening for fetal anomalies is a real possibility when the fetus is bigger than 50 mms in size (crownrump-length). A prospective study was started in February 1992. Since that time transvaginal sonography has been offered to every woman in the 12th week of their pregnancies. Twenty structural anomalies have been diagnosed in 18 fetuses during a 17-month period. Besides of detecting "classical" congenital anomalies, nuchal oedema is considered to be a promising sign for screening chromosomal abnormalities especially Down syndrome. In this series 4 cases of trisomy 21 has been diagnosed by karyotyping in the presence of nuchal oedema. The results of their study suggest, that more and more fetal anomalies can be detected in the first trimester of pregnancy, therefore transvaginal sonography is offered to use as a screening method, being a powerful diagnostic tool for early diagnosis.