Insulin-like growth factor binding protein-1 (IGFBP-1) during normal pregnancy.

Background: Insulin-like growth factor (IGF) binding protein-1 (IGFBP-1) is the main binder of IGFs in secretory endometrium and decidualized stromal endometrial cells and IGFBP-1 has been shown to modulate IGF bioactivities and influence fetal growth. To be able to evaluate IGFBP-1 values during pregnancy it is important to establish normal values in pregnant women.

Materials & Methods: We have studied IGFBP-1 concentrations in maternal plasma from 52 healthy women with normal singleton pregnancies. Several plasma samples were collected from each woman and the samples were grouped according to gestational age into the following periods: week 7-17; week 17-24; week 24-28; week 28-31; week 31-34; week 34-38; -2 to 0 weeks prior to delivery and postpartum (>6 weeks after delivery).

Results: The 2.5 and 97.5 percentiles for IGFBP-1 were calculated according to the recommendations of the International Federation of Clinical Chemistry on the statistical treatment of reference values.

Conclusions: IGFBP-1 is increased during pregnancy compared to postpartum. Two peaks, at week 17-24 and just before delivery, were observed.