Uncultured cells in amniotic fluid from normal and abnormal foetuses

Abstract

Direct smears of uncultured amniotic fluid cells were analyzed in 41 pregnancies at 17-22 wk of gestation. These included 27 normal pregnancies where a healthy child was born at term, 6 anencephalic and 5 spina bifida pregancies, and 3 other abnormal pregnancies. In normal amniotic fluid, epithelioid cells predominated but small numbers of histiocyte-like cells, typical macrophages and elongated cells were also present. The proportion of macrophages and elongated cells was significantly increased in all anencephalic cases. Of the spina bifida cases, 2 also showed abnormal cellular proportions. Hemosiderin and lipid material was demonstrated in some of the macrophages. Tissue smears and histological preparations suggest that these cells may originate from both the amnion and the fibrovascular membrane covering the neural lesion. This direct method of observation of amniotic fluid cells, not involving culture techniques, could provide a rapid means of prenatal diagnosis of anencephaly, and may help in the diagnosis of spina bifida.