Fetal vascular response to maternal deep-vein thrombosis and subsequent heparin therapy.

The fetal umbilical and cerebral Doppler changes were recorded in a 27-year-old primigravida referred at 38 weeks for the treatment of an iliofemoral vein thrombosis. On admission and in comparison to a previous Doppler assessment systematically performed during growth scan at 37 weeks, the umbilical resistance index (URI) demonstrated an increase of 19%, the cerebral resistance index (CRI) a reduction of 15% and the cerebral-umbilical (C/U) ratio a decrease of 29% reaching the lowest value of 1.05. Under intravenous heparin therapy, Doppler normalisation was observed within 1 week and the mother delivered a healthy, non-hypoxemic baby by caesarean section at 39 weeks and 2 days. This observation suggests that deep-vein thrombosis (DVT) may, in some cases, be responsible for transient fetal hypoxia. Moreover, treatment with intravenous heparin had a direct beneficial effect on the fetus as it improved placental hemodynamics and fetal oxygenation.