Effects of maternal infections on fetal adrenal steroid production

We sought to determine the effect of maternal infections on the fetal hypot halamic-pituitary-adrenal axis. Umbilical cord blood was collected at vagin al delivery after labor (24-44 wk. gestation) from 361 infants of women hav ing normal pregnancy( apart from preterm delivery in some) and 110 infants of women diagnosed with infections: 86% of these women had amnionitis. Infa nts exposed to antenatal corticosteroids, being growth retarded, or having developmental abnormalities that would be expected to alter function of the hypothalamic-pituitary unit were excluded. Umbilical cord serum was assaye d for dehydroepiandrosterone sulfate (DS) and for cortisol. The data were a nalyzed by use of SBS. The gestational age of the infants of normal women ( 35.8 +/- 0.2 wk., Mean +/- SE) was greater than that of the infants of wome n having infections (34.3 +/- 0.4 wk., P = 0.003). Umbilical cord serum lev els of DS and cortisol rose as a function of gestational age in both groups of infants (P<0.01). Despite being, on average, 1 wk younger than the norm al infants are, the infants of women having infections during pregnancy had higher serum levels of cortisol and DS than did those infants of the norma l women. These data are consistent with activation of the fetal hypothalami c-pituitary-adrenal axis in pregnancies complicated by maternal infections. Such a fetal response could be the consequence of transplacental passage o f products of the activated maternal immune system.