Failure of amniotic-fluid-cell growth: is it related to fetal aneuploidy?

We investigated outcome in patients whose amniotic-fluid-cell samples showed unexplained growth failure in culture. 32 of 7872 amniocentesis samples were classified as unexplained growth failures. 10 women did not have repeat cytogenetic testing, but among their pregnancies there were 4 abnormal outcomes (1 fetal bladder-outlet obstruction, 2 stillbirths, and 1 acardiac twin). Of the 22 patients who had repeat karyotypic analysis, 18 had normal fetal karyotypes. However, 4 fetuses were aneuploid (2 trisomy 21, 1 trisomy 13, and 1 Pallister-Killian syndrome).