The Efficacy of Placental Alpha Microglobulin-1 Testing in the Diagnosis of Rupture Membranes between 32- and 37-Weeks of Gestation

Abstract

Background: Premature or prolabor rupture of membranes (PROM) is a spontaneous rupture of the amniotic membranes before the onset of uterine contractions and it consists for about 10%, while preterm premature rupture of membranes (PPROM) is defined when the membranes rupture occurs before 37 weeks, it is recorded in about 30% of women with PROM.

Objective: This study was conducted to determine the diagnostic accuracy of placental alpha microglobulin-1 (PAMG-1) assay in comparison to the routine clinical methods (fluid pool in posterior fornix test and ultrasound) for detecting rupture of membranes.

Methods: A Retrospective cross-sectional study, from February 2018 to February 2020 at Duhok Hospital for obstetrics and gynecology/ Kurdistan/ Iraq was carried out on 400 women whom they have suspicion of having rupture membranes. Clinical evaluation performed to the participants including history, clinical examination which involved the assessment of fluid pool in posterior fornix (FP) test. U/S to detect the Amniotic Fluid Index and placental alpha microglobulin-1 immunoassay (PAMG-1) test. The actual rupture of membranes was diagnosed on review of the medical records after delivery (considered as a final diagnosis). Sensitivity, specificity, negative and positive predictive values were calculated.

Results: The age of the recruited patients were between 19 to 41 years old, and Mean±SD was 35.7±6.54, (13%) had previous history of PROM. The results of the performed tests were in the following: PAMG1 sensitivity was (94.8%) and positive predictive value (PV+) was excellent (98.91%), the specificity was (75%) and negative predictive value (PV-) was (37.5%). Regarding fluid pool collection test, the sensitivity (78.1%), PV+ was very good (96.25%) and specificity (25%), but the PV- was very low (4.5%). The U/S showed sensitivity of (48.9%), with excellent of PV+ (97%), specificity (75%), and low PV- (5.7%).

Conclusions: The PAMG-1 immunoassay is an accurate test for the detection of premature rupture of amniotic membranes, compared to fluid pool in the posterior fornix test and ultrasound imaging.