Modification of the fetal reactivity by an intravenous glucose load to the mother.

Abstract

The effect of an intravenous maternal glucose load upon fetal activity and FHR was studied 51 times in 48 pregnancies at 34 or more weeks, in which the fetuses were classified as non-reactive during the NST. The initiation of fetal muscular activity was observed in 44 instances (41 fetuses) approximately 6 minutes after a 6 grams glucose load to the mother, which lead to the diagnosis of a state of fetal well-being without the need of a CST. In the 7 cases which were not responsive to the load, CSTs were performed; of these, 5 were positive, 1 negative and 1 suspicious. These pregnancies resulted in one fetal death during the 12 hours following CST and 5 newborns showed an APGAR Score less than 4 at one minute, with 2 neo-natal deaths. The reason for the negative glucose load test with negative CST was probably related to hemodynamic changes induced by intra-amniotic bleeding following a bloody amniocentesis, and not to the lack of fetal energy substate. The proposed method may constitute a screening possibility for the clinical management and prognosis of the hypoactive fetus, because the glucose load to the mother may release the somatic activity of the non-hypoxemic fetus. A fetus unable to show any significant increase in glucose uptake, even with increasing maternal-fetal gradients, could be identified by the negative response to the test.