A longitudinal study of maternal plasma insulin-like growth factor bindingprotein-1 concentrations during normal pregnancy and pregnancies complicated by pre-eclampsia

Insulin-like growth factor binding protein-1 (IGFBP-1) is synthesized by th e decidual stroma, and is thought to act locally to inhibit IGF activity an d so limit trophoblast invasion. Cross-sectional studies have reported conf licting data on maternal circulating concentrations of IGFBP-1 in early pre gnancy before the development of pre-eclampsia, A longitudinal study was pe rformed in 10 women who went on to develop pre-eclampsia and a group of 12 normal pregnant controls, chosen to be similar for maternal age, booking bo dy mass index (BMI) and gestational age. Maternal IGFBP-1 concentrations we re measured in plasma obtained at 16, 20, 24, 28, 32 and 36 weeks. Plasma I GFBP-1 concentrations were unchanged over this period in normal pregnancy. In contrast, the concentrations in women who developed pre-eclampsia increa sed progressively. At 16, 20, and 24 weeks the concentrations were signific antly lower compared to normal pregnancy, at 28 and 32 weeks, similar, but by 36 weeks the concentrations were significantly greater than the normal c ontrols. The data show that circulating IGFBP-1 concentrations are lower in early pregnancy before the development of preeclampsia, Thus, it is sugges ted that IGFBP-1-induced inhibition of IGF activity is unlikely to be respo nsible for the impaired trophoblast invasion observed in preeclampsia.