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 PAPPA 38 000 vs 55 333 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 <= 30 000 mUl(-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 <= 30 000 mUl(-1) at admission was associated with increased risk for preterm birth <= 7 days, supporting active management and therapeutic approach in these women.