PAPP-A levels as an early marker of idiopathic preterm birth: A pilot study

Objective: To evaluate late PAPP-A levels as predictive of preterm birth in symptomatic women. Study Design: Prospective cohort study of singleton gestations, 23 to 34 weeks, and symptoms of preterm labor. PAPP-A, IGF-I and IGF-III analysis were performed. Primary end point was delivery ≤7 days. Accuracy and optimally predictive PAPP-A values were based on receiver operator characteristic (ROC) curves. Result: In all, 26 women (51%) delivered ≤7 days post-admission (Group 1); 25 women (49%) >7 days (Group 2). Group 1 mean PAPP-A = 38000 vs 55333 for Group 2 (P < 0.04). Group 1 mean gestational age at delivery = 29 weeks vs 37 weeks for Group 2 (P < 0.00014). PAPP-A level ≤30000 mU^-1 had highest specificity (88%), sensitivity (50%), and positive predictive (81%) and negative predictive (62%) values for delivery ≤7 days. ROC area under curve = 0.703. Conclusion: PAPP-A levels ≤30000 mU^-1 at admission was associated with increased risk for preterm birth ≤7 days, supporting active management and therapeutic approach in these women.