Combined insulin-like growth factor binding protein-1/interleukin-6 (Premaquick) versus fetal fibronectin for predicting preterm delivery among women with preterm contractions

Objectives: To compare accuracy between Premaquick (combined test for native insulin-like growth factor binding protein-1 (IGFBP-1), total IGFBP-1, and interleukin-6) and fetal fibronectin (Ffn) in predicting preterm delivery. Methods: Prospective study among women at 28–36⁺⁶ gestational weeks with threatened preterm labor attending Federal Medical Center, Owerri, Nigeria, from August 2017 to February 2019. Cervico-vaginal fluids were collected and tested by Premaquick and Ffn tests. The women were followed for 14 days. Sensitivity, specificity, and negative (NPV) and positive (PPV) predictive value for delivery were compared between the tests. Results: Among 213 women assessed for eligibility, 183 were enrolled and 175 completed the study. The sensitivity, specificity, PPV, NPV, and accuracy of the Premaquick versus Ffn tests were, respectively, 96.3% versus 51.9%, 97.6% versus 98.4%, 89.7% versus 87.5%, 99.2% versus 90.3% and 97.3% versus 90.0% for preterm delivery within 14 days. Ffn had higher specificity (98.5% vs 97.8%; P>0.99), but Premaquick had higher PPV (92.7% vs 90.9%; P>0.99). Conclusion: Both tests seem to have high utility in predicting preterm delivery, but Premaquick showed higher accuracy in terms of sensitivity and PPV. Premaquick might be a feasible alternative to Ffn for predicting preterm delivery among symptomatic women in a low-income setting.