Serum insulin-like growth factors in normal pregnancy and in pregnancies complicated by preeclampsia

Background. Lower levels of insulin-like growth factor I (IGF-I) have been shown to be associated with preeclampsia and also with a reduced risk of breast cancer later in life. Lower levels of IGF before clinical signs of preeclampsia could be one possible mechanism in the etiology of preeclampsia as well as for the reduced risk of breast cancer associated with preeclampsia. We have prospectively investigated maternal serum levels of IGF-I, IGF-II, and the main binding protein insulin-like growth factor binding protein 3 (IGFBP-3) in women with and without preeclampsia. Methods. We used maternal serum samples from a Swedish-Norwegian cohort study obtained in the 17th and 33rd gestational week from 30 women who subsequently developed preeclampsia and 128 women who did not develop preeclampsia. Results. There were no significant differences in serum concentrations IGF-I and IGFBP-3 in the 17th or the 33rd week of gestation between women who developed preeclampsia or not. Compared with nonpreeclamptic women, preeclamptic women had significantly higher serum levels of IGF-II in week 33, but there was no difference in week 17. Conclusion. In women who developed preeclampsia, we found no support for the hypothesis that the disease was preceded by lower serum levels of IGF-I and IGF-II, or higher serum levels of IGFBP-3. However, among women who later developed preeclampsia, serum levels of IGF-II were significantly higher in the 33rd gestational week.