[Amniotic fibronectin in normal pregnancy and pregnancy with fetal anencephaly].

Fibronectin, which is an important protein in plasma and in surface cells was calculated in amniotic fluid using a laser ray nephelemetric technique. In normal pregnancies (in 72 samples studied) this protein which rises towards the 18th week of amenorrhoea (mean +/- S.D.: 60.8 +/- 16.0 mg/l), decreases steadily to term (mean 14.8 +/- 8.9 mg/l). In fetal anencephaly (10 samples tested) high levels were also found but the difference as compared with normal levels was not significant. This measurement does not therefore constitute an extra way of screening for closure of the neural tube.