Evaluation of insulin-like growth factor binding protein-1 as a diagnostic tool for rupture of the membranes

OBJECTIVE To evaluate the diagnostic value of insulin-like growth factor binding protein-1 (IGFBP-1) as an indicator of ruptured fetal membranes. METHODS IGFBP-1 concentrations were measured on 42 paired cervicovaginal samples before and after membrane rupture, using an immunoenzymatic assay. A PROM test [dipstick detecting IGFBP-1 with a cutoff value of 25 micrograms/l (A)], a BTB test (B), a ROM-Check (C), and a fern test (D) were compared in diagnosing ruptures of the membranes in 48 patients. RESULTS The optimal cutoff concentration was between 20.1 micrograms/l and 148.4 micrograms/l by receiver operating characteristic curve analysis. The PROM test had the highest sensitivity (94.7%) and highest specificity (93.3%) (sensitivity of A-D, B-D, C-D and specificity of A-B: p < 0.05 by chi 2-test). Unlike the other tests, the PROM test is unaffected by contamination, cervical dilatation, or uterine contraction. CONCLUSIONS The measurement of IGFBP-1 in vaginal fluids is useful for the diagnosis of ruptured fetal membranes.