Umbilical cord serum activin A levels are increased in pre-eclampsia with impaired blood flow in the uteroplacental and fetal circulation

The aims of the present study were to evaluate the umbilical cord serum activin A concentrations in complicated pregnancies and also to explore the relationship between activin A levels and blood flow velocity in fetal arteries. Umbilical cord blood samples were obtained postpartum after a full term uneventful gestation (control group, n = 40), and from pregnancies complicated by gestational diabetes (n = 13), preterm labour (n = 18), or pre-eclampsia (n = 19). Cord serum activin A levels were three-fold higher in pregnancies complicated by pre-eclampsia (1.17 +/- 0.14 ng/ml, p < 0.01) than in the control group (0.43 +/- 0.03 ng/ml), but were unaltered in the diabetes and preterm labour groups. The pre-eclampsia group had a marked increase of umbilical artery pulsatility index (PI) and also a decrease of middle cerebral artery PI (p < 0.01). Furthermore, activin A concentration correlated directly with the umbilical artery PI (r = 0.540, p = 0.021), with the length of stay in the Neonatal Intensive Care Unit (r = 0.857, p < 0.001) and also with cord blood pH (r = -0.886, p < 0.001). In conclusion, umbilical cord serum activin A levels are increased in the presence of pre-eclampsia and provide an indirect marker of impaired blood flow in the uteroplacental and fetal circulation.