Late pregnancy associated plasma protein A levels decrease in preterm labor

Abstract

Objective. The purpose of the present study is to evaluate late, ‘at admission’, Pregnancy-associated plasma protein-A (PAPP-A) levels as a predictor of preterm birth in women with complaints of preterm labor or preterm painful contractions.Methods. Prospective cohort study of singleton gestations, 23–37 weeks, and symptoms of preterm labor. Primary end point was delivery < 37 weeks. Predictive PAPP-A values were calculated both for preterm delivery and threatened preterm delivery on receiver operator curve.Results. In all, 41 women (38.3%) delivered before 37 weeks (Group 1); 32 women (30.7%) had symptoms of preterm labor but did not deliver preterm (Group 2); 31 women (29.7%) delivered term (Group 3, control). Mean PAPP-A levels in preterm-labor and its matched control were 33.4 ± 19.9 and 52.5 ± 25.4 mIU/ml, respectively, and difference was statistically significant (p = 0.003). Mean PAPP-A level in threatened preterm labor group was 47.6 ± 25.3 mIU/ml and difference was significant compared to preterm-labor, but not significant compared to control group (p = 0.028 and p = 0.74, respectively).Conclusion. Late PAPP-A levels decreased in preterm labor, levels < 29.8 mIU/ml was associated with increased risk for preterm birth, supporting active management whereas cutoff value of 33.6 mIU/ml is useful for discrimination of preterm birth from threatened preterm birth reaching to term.