Serum insulin-like growth factor binding protein-1 at 16 weeks and subsequent preeclampsia

Objective: To determine whether serum concentrations of insulin-like growth factor-binding protein-1 (IGFBP-1), a major decidual protein, at 16 weeks' gestation differ between women who later develop pregnancy-related hypertension and normotensive women. Methods: Concentrations of IGFBP-1 were measured using immunoenzymometric assay in serum samples collected for alpha-fetoprotein (AFP) and free beta subunit of hCG (free beta-hCG) determinations in a Down syndrome screening program at 16 weeks' gestation in a population-based cohort of 1049 nulliparous women. After exclusion of subjects with multiple pregnancies, insulin-dependent diabetes, major fetal malformations, and incomplete data, 917 subjects remained eligible. Results: The mean levels (+/- standard deviation) of IGFBP-1 were significantly lower in 34 women who later developed preeclampsia (73 +/- 43 mu g/L, P < .01) and in 80 women with White A diabetes (84.7 +/- 53 mu g/L, P < .01) compared with controls (103 +/- 58 mu g/L). In seven women with White A diabetes and subsequent preeclampsia IGFBP-1 levels were especially low (41 +/- 34 mu g/L). The concentrations of AFP and free beta-hCG in the subgroups with hypertensive disorders were not significantly different from those of normotensive women. Conclusion: Decreased IGFBP-1 levels at 16 weeks' gestation in women who develop preeclampsia might indicate impaired decidual function. Hyperinsulinemia, a known risk factor for preeclampsia, might contribute to decreased concentrations of serum IGFBP-1. However, due to low sensitivity, assay of serum IGFBP-1 was not clinically valuable for predicting preeclampsia. (C) 2000 by The American College of Obstetricians and Gynecologists.