Serum insulin-like growth factor-I and insulin-like growth factor binding protein-3 in premature rupture of membranes

Background. The aim of the study was to evaluate whether the circulating levels of insulin-like growth factor-I (IGF-I) and its major circulating binding protein, IGFBP-3, are affected in premature rupture of membranes (PROM) and preterm delivery. Methods. The levels of IGF-I and IGFBP-3 were measured in 32 pregnant women with PROM and in 27 healthy gestational age-matched pregnant women. Statistical analyzes were performed by analysis of variance. Results. All the patients with PROM had preterm delivery, at a gestational age of 31.9 +/- 0.4 weeks (mean +/- SEM). In the control subjects, pregnancy proceeded to term. In the PROM patients, the serum IGF-I and IGFBP-3 levels (289 +/- 21 ng/ml and 8248 +/- 407 ng/ml, respectively) were not statistically different from those in the control subjects (275 +/- 22 ng/ml and 7579 +/- 488 ng/ml). Seventeen patients with PROM showed a rise in serum C-reactive protein, indicating subclinical intrauterine infection. Also in this subgroup of patients the levels of serum IGF-I (281 +/- 27 ng/ml) and IGFBP-3 (9010 +/- 633 ng/ml) were not different from those in the control subjects. Before delivery, serial serum samples were available from 22 patients with PROM. No consistent changes in IGF-I or IGFBP-3 concentrations were seen during the mean follow-up period of 9 days. Conclusions. IGF-I and IGFBP-3 do not appear to play any significant role in the maintenance of pregnancy in PROM patients with preterm delivery, whether or not associated with emerging intrauterine infection.