Placental α-Microglobulin-1 in Vaginal Secretions of Women with Evidence of Preterm Labor

Objective  To evaluate the presence of placental α-microglobulin-1 (PAMG-1) in vaginal secretions in women with symptoms of preterm labor and assess its use as a predictor of preterm birth. Study Design  A prospective cohort study of women between 16 and 34 weeks of gestation with symptoms of preterm labor and intact membranes was conducted. The presence of PAMG-1 was determined using a commercially available kit (AmniSure, AmniSure International LLC, Boston, MA). Results  A total of 100 women were enrolled, of which 86 had outcome data available. PAMG-1 was detected in 19/86 (22.1%) subjects. These women were more likely to deliver within 7 days than those without PAMG-1 detected (6/19 [31.6%] vs. 5/67 [7.5%]; odds ratio 5.6; 95% confidence interval 1.5–21.6). These findings persisted after adjusting for potential confounders. The sensitivity was 54.6%, specificity was 82.7%, positive predictive value was 31.6%, and the negative predictive was 92.5%. Conclusion  The presence of PAMG-1 is associated with an increased likelihood of delivery within 7 days.