First-trimester diagnosis of cystic hygromata by transvaginal sonography.

This paper reports two cases of fetal nuchal cystic hygromata diagnosed in the first trimester of pregnancy by transvaginal sonography. In the first case, at 10 weeks' gestation, in addition to the hygromata, the fetus had an exomphalos. In the second case, at 13 weeks' gestation, the fetus had hydrocephalus and pleural effusion. Transabdominal chorion villus sampling was carried out and the fetal karyotypes were trisomy 18 and trisomy 21, respectively.