Cervical phosphorylated insulin‐like growth factor binding proteın‐1 for the prediction of preterm delivery in symptomatic cases with intact membranes

Abstract

This prospective, observational study was an attempt to evaluate whether a positive cervical phosphorylated insulin-like growth factor binding protein-1 admission test in women with signs and symptoms of preterm labor (PTL) may be useful in the prediction of women who will deliver prematurely. Pregnant women with confirmed gestational age between 24 and 37 weeks' gestation with <3 cm cervical dilatation and intact membranes were included in the study. Prior to digital examination, a sterile speculum examination was performed using a dacron swab rotated in the external cervical os for 15 s. The test was based on immunochromatographic qualitative analysis of cervical phosphorylated insulin-like growth factor binding protein-1. Test (+) and (-) cases were evaluated in terms of maternal demographic characteristics and neonatal outcomes. A total of 68 cases were enrolled in the study. There were no statistically significant differences between test (+) and (-) groups, in terms of maternal characteristics or adverse neonatal outcomes. However, cases with + test had high Bishop scores on admission (P = 0.01) and gestational age at delivery (P = 0.003). For deliveries within 7 days of admission, the strongest predictors were test positivity (RR:24,%95CI:2.8-204, P < 0.0001) and Bishop score (RR:1.3, %95CI: 1.0-1.6, P = 0.03). For deliveries <34 weeks' gestation, the test had a sensitivity, specificity, positive predictive values, negative predictive values, +likelihood ratios and -likelihood ratios of 70%, 74%, 48%, 88, 2.8 and 0.39, respectively. Among women with signs and symptoms of PTL, the high negative predictive value of this test to predict the PTL <34 weeks' gestation as well as within 7 days of delivery may be of value in the reassurance of patients, avoiding unnecessary medical interventions.