Comparison of placental alpha microglobulin-1 protein assay (Amnisure) with speculum examination for the diagnosis of premature preterm rupture of membranes (PPROM): a clinical evaluation

Abstract

In this study, we aimed to compare the clinical outcomes of Premature Preterm Rupture of Membranes (PPROM) cases diagnosed by classical speculum examination and by placental alpha microglobulin-1 protein (PAMG-1) assay. The medical records of all patients with singleton pregnancies that were diagnosed with PPROM were retrospectively reviewed. Singleton pregnancies with PPROM diagnosis that was confirmed either by direct visualisation of amniotic fluid leaking through the cervix or by placental alpha microglobulin-1 protein (PAMG-1) assay if no amniotic fluid leakage was documented were included in the study. Demographics, prenatal and postnatal characteristics were reviewed from the medical charts and were recorded. The study included 138 pregnancies with PPROM; 111 patients in clinical speculum examination group and 27 in PAMG-1 assay group. There were no significant differences in maternal and pregnancy characteristics between the clinical speculum examination and PAMG-1 assay groups. Foetal outcomes were comparable between clinical speculum examination and PAMG-1 assay groups. In the clinical speculum examination group, there were nine (8.1%) chorioamnionitis cases, however, there were no chorioamnionitis cases in the PAMG-1 assay group during the latency period (p = .21).Impact statement What is already known on this subject?Placental alpha microglobulin-1 protein assay uses immunochromatography method to detect trace amount of placental alpha microglobulin-1 protein in vaginal fluids and has high sensitivity and specificity for ROM diagnosis. However, to the best of our knowledge, the clinical outcome of ROM cases detected by classical speculum examination and by placental alpha microglobulin-1 protein assay has not been compared in the literature previously. What do the results of this study add?Although statistically insignificant, cases diagnosed by PAMG-1 assay had lower risk of chorioamnionitis during latency period. What are the implications of these findings for clinical practice and/or further research?Whether cases diagnosed by PAMG-1 assay represent a milder form of rupture of membranes than cases diagnosed by classical speculum examination group warrants further research.