ULTRASOUND IMAGING OF FETAL NECK ANOMALIES - IMPLICATIONS FOR THE RISK OF ANEUPLOIDY AND STRUCTURAL ANOMALIES

This study summarizes 24 000 transvaginal ultrasound examinations whic h were performed in a predominantly low-risk population at 14-16 weeks ' gestation. 1254 (5.2 per cent) fetuses had a nuchal fold or a non-se ptated cystic hygroma. Of these fetuses, 140 (11.1 per cent) had addit ional structural anomalies. Cardiovascular anomalies were the most com monly detected structural malformations. Forty-three (3.4 per cent) fe tuses were aneuploid. Trisomy 21 was the most common chromosomal anoma ly (n=27). Aneuploidy was significantly more common in fetuses who had a nuchal finding and an associated structural anomaly. The prevalence of nuchal fold and non-septated cystic hygroma, as well as the incide nce of their associated structural anomalies, was similar. Based on th ese data, it is concluded that a complete ultrasonic survey of the fet us and karyotyping are advocated in fetuses with a nuchal abnormality, irrespective of maternal age or triple serum screening results. (C) 1 997 by John Wiley & Sons, Ltd.