Rapid karyotyping in non-lethal fetal malformations.

Pure fetal blood samples were obtained fetoscopically, at 16-36 weeks' gestation, from 118 pregnancies complicated by ultrasonographically demonstrable fetal anomalies. Cytogenetic analysis of fetal lymphocytes yielded results within two to four days. Chromosomal abnormalities were found in 12 of 37 fetuses with non-haemolytic hydrops fetalis, 8 of 12 with exomphalos, 1 of 3 with duodenal atresia, 9 of 39 with obstructive uropathy, 1 of 3 with unilateral pleural effusion, 2 of 10 with severe growth retardation and oligohydramnios, 2 of 9 with isolated hydrocephalus, and 3 of 4 with choroid plexus cysts (of the last 4, 1 also had obstructive uropathy and 1 exomphalos). 3 fetuses with gastroschisis were cytogenetically normal. The results suggest that rapid fetal karyotyping is advisable in all cases of non-lethal or potentially correctable fetal malformations detected sonographically during the second or third trimester of pregnancy.