Infant size and the association between maternal circulating angiogenic factors and preeclampsia

Objective:to assess the effect of infant size as a marker of placental function on the association between preeclampsia and the ratio of soluble fms-like tyrosine kinase 1 (sflt-1) to placental growth factor (plgf).study design:the angiogenic factors sflt-1 and plgf were measured prospectively at 26 weeks gestation in 2322 women. pregnancies were stratified by whether or not they were complicated by preeclampsia, the timing of delivery, and birthweight z-score.result:independent of preeclampsia status, women with small infants (z < -1.0) have an increased sflt-1/plgf ratio, and women with large infants (z > 1.0) have a decreased ratio. among pregnancies yielding small infants, the sflt-1/plgf ratio is markedly elevated in preeclamptic pregnancies requiring delivery before 37 weeks (110.0 vs. 17.9, p < 0.0001) but not in preeclamptic pregnancies delivered at term. the strength of the association between preeclampsia and the sflt-1/plgf ratio is increased for small infants compared to normal-sized or large infants.conclusion:the sflt-1/plgf ratio in the late second trimester is similarly elevated in women with preeclampsia and in women with small infant size and more markedly elevated in a syndrome of placental dysfunction characterized by preeclampsia, preterm delivery, and growth restriction.