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 p re-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 si ngleton pregnancy and five with twin pregnancy). Main outcome measures Serum IGF-I and IGFBP-1 levels were determined by radioimmunoassay. R esults Serum IGF-I concentrations increased as pregnancy progressed. I n the third trimester, serum IGF-I levels in singleton preterm deliver ies were lower than those in normal pregnancies, and IGFBP-1 concentra tions were higher than those in normal pregnancies. This phenomenon wa s not obvious in the second trimester. Maternal circulating IGFBP-1 le vels were correlated inversely with birthweight in women with singleto n preterm delivery. Conclusions Neither IGF-I nor IGFBP-1 appears to p lay a significant role in preterm delivery since maternal serum IGF-I and IGFBP-1 levels are similar in preterm and term deliveries.