Levels of insulin-like growth factor-I and insulin-like growth factor-binding protein-1 in pregnancy with preterm delivery.

OBJECTIVE

To investigate the relationship between preterm delivery and maternal serum insulin-like growth factor-I (IGF-I) and insulin-like growth factor-binding protein-1 (IGFBP-1) levels.

DESIGN

A study over a 12 month period in which all samples were collected according to a pre-set protocol.

SETTING

St. Bartholomew's Hospital, London.

SUBJECTS: Thirty-eight nonpregnant adult females, 456 pregnant women at various gestational ages, 84 women with average-for-gestational-age babies at term delivery, and 49 pregnant women with preterm delivery (44 with singleton pregnancy and five with twin pregnancy).

MAIN OUTCOME MEASURES: Serum IGF-I and IGFBP-1 levels were determined by radioimmunoassay.

RESULTS

Serum IGF-I concentrations increased as pregnancy progressed. In the third trimester, serum IGF-I levels in singleton preterm deliveries were lower than those in normal pregnancies, and IGFBP-1 concentrations were higher than those in normal pregnancies. This phenomenon was not obvious in the second trimester. Maternal circulating IGFBP-1 levels were correlated inversely with birthweight in women with singleton preterm delivery.

CONCLUSIONS

Neither IGF-I nor IGFBP-1 appears to play a significant role in preterm delivery since maternal serum IGF-I and IGFBP-1 levels are similar in preterm and term deliveries.