Publication:

Double blinded study on comparison of phosphorylated insulin like growth factor binding protein 1 test and fetal fibronectin test for prediction of preterm delivery

Background Recently new markers like fetal fibronectin (FFN) and phosphorylated Insulin like growth factor binding protein 1 (phIGFBP-1) have been found useful in diagnosis of pre-term labor. Fetal fibronectin (FFN) and phosphorylated Insulin like growth factor binding protein 1 (phIGFBP-1) were compared to predict the risk of pre- term delivery.

Methods Cervicovaginal samples of 50 symptomatic and 50 asymptomatic pregnant women were tested. Statistical analysis was done using chi square test, fisher’s exact test for qualitative data and for quantitative data unpaired student t test and Mann Whitney test were used.

Results For Symptomatic group phosphorylated Insulin like growth factor binding protein 1 (phIGFBP-1) and fetal fibronectin (FFN) had 100% sensitivity and 100% NPV for predicting delivery within 48 hours, 7days and 14 days. Specificity and PPV of FFN was higher than phIGFBP-1 to predict delivery (Specificity: within 48 hours 63.2% vs 52.6% within 7 days 72.7% vs 60.6%, within 14 days 75% vs 62.5%, ≤37 weeks 76% vs 56%; PPV: within 48 hours 46.2% vs 40%, within 7 days 65.4% vs 56.7%, within 14 days was 69.2% vs 60% and ≤37 weeks 76.9% vs 63%).

Conclusions Rapid bed side dip stick tests for detecting FFN and ph IGFBP-1 in cervicovaginal secretions are useful clinical adjuncts in ruling out delivery within 14 days of test in symptomatic patients, thus avoiding unnecessary hospital stay and medical interventions. However, FFN has slightly higher NPV in predicting risk of pre term delivery.