Value of cervical phosphorylated insulinlike growth factor binding protein-1 in the prediction of preterm labor

OBJECTIVE: To determine the value of cervical phosphorylated insulinlike growth factor binding protein-1 (IGFBP-1) in the prediction of preterm labor. STUDY DESIGN: In this prospective study, 77 pregnant women, gestational age 24-36 weeks, were enrolled in the study. Twenty women with completely healthy pregnancies formed the control group. Fifty-seven women with signs and symptoms of preterm labor formed the study group. Phosphorylated IGFBP-1 in cervical secretions was assessed in all patients by using a qualitative, immunochromatographic, 1-step dipstick test. Cervical length was measured by transvaginal sonography. RESULTS: The IGFBP-1 test was negative in all patients in the control group (n = 20), and all of them delivered after 37 weeks, while the test was positive in 15 of 45 (33.3%) patients in the study group. The correlation between cervical length and gestational age at the time of delivery in patients with a positive phosphorylated IGFBP-1 test (n = 15) was significant (r = .553, P = .03). The sensitivity, specificity, positive predictive value and negative predictive value for the phosphorylated IGFBP-1 test were 78%, 87%, 73% and 90%, respectively. CONCLUSION: Use of a 1-step dipstick test for detecting phosphorylated IGFBP-1 in cervical secretions is of value in the prediction of preterm labor. The high negative predictive value of the test may be useful in avoiding unnecessary medical interventions.