IGFBP-1 IN THE PLACENTA, MEMBRANES AND FETAL CIRCULATION - LEVELS AT TERM AND PRETERM DELIVERY

Samples of maternal blood, amniotic fluid, placenta, fetal membranes a nd umbilical venous blood were collected from 59 women at vaginal deli very (32-41 weeks gestation) and 15 women at delivery by Caesarean sec tion (37-41 weeks gestation). Umbilical vein levels of IGFBP-1 were si gnificantly lower in deliveries prior to the onset of labour (elective Caesarean section) than those during normal vaginal delivery. These l evels were, in turn, significantly lower than those delivered by emerg ency Caesarean section. This difference was not seen in any of the oth er tissues examined. Concentrations of IGFBP-1 were lower in placenta and membrane extracts from preterm deliveries than in term deliveries. This difference was not observed in maternal or fetal serum or in amn iotic fluid. This study confirms that the fetal membranes are a major source of IGFBP-1 and that fetal circulating levels are raised where t here is evidence of fetal hypoxia. The absence of a comparable rise in levels in placenta, membranes or amniotic fluid suggests that the ori gin of this increase is from fetal tissue.