Maternal plasma concentrations of insulinlike growth factor-1 and insulinlike growth factor-binding protein-1 in early pregnancy and subsequent risk of preeclampsia.

OBJECTIVES: We investigated the relationship between maternal plasma free insulinlike growth factor-1 (IGF-1) and insulinlike growth factor-binding protein-1 (IGFBP-1) concentrations and risk of preeclampsia. DESIGN AND METHODS: Maternal blood samples were collected at 13 weeks' gestation on average. From the cohort, we selected 53 women who developed preeclampsia and 477 who remained normotensive. Free IGF-1 and IGFBP-1 concentrations were measured using immunoassays. Logistic regression procedures were used to calculate odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS: Women who developed preeclampsia had 18% and 27% lower concentrations of free IGF-1 and IGFBP-1, respectively, than controls (P < 0.05). There was a 57% reduced risk of preeclampsia among women with free IGF-1 concentrations of >or= 0.81 ng/mL (OR = 0.43, 95% CI 0.23-0.83) and a 43% reduced risk among women with IGFBP-1 concentrations of >or= 72.36 ng/mL (OR = 0.53, 95% CI 0.23-1.21). CONCLUSIONS: Alterations of free IGF-1 and IGFBP-1 concentrations in maternal plasma during early pregnancy are associated with risk of preeclampsia. These associations may help to further elucidate the pathologic processes of preeclampsia.