AmniSure: A Point of Care Diagnostic for Preterm, Term Prelabor Rupture of Membranes

Abstract

Background: Accurate, early diagnosis, prompt appropriate intervention is essential in the management of rupture of membranes (ROM), especially preterm.

Aim: The aim was to determine efficacy of AmniSure rapid immunoassay placental alpha‑microglobulin‑1 test for accurate diagnosis of true ROM in women with watery discharge after 28 weeks gestation, compare with conventional methods.

Subjects and Methods: Study was carried out in women presenting with ROM to labor the room of referral rural medical institute in Central India after ethical approval. Prospective study was performed in women presenting with symptoms/signs of ROM after 28 weeks of gestation. Sterile speculum examination was performed to observe pooling of liquor. Nitrazine, ferning tests were done to diagnose ROM. Vaginal examination was performed to determine cervical dilatation, effacement, station of presenting part in term cases. If all or 2 of 3 tests (pooling, ferning, and nitrazine) were positive, provisional diagnosis of ROM was made. Confirmation of ROM was done at birth. However, if 2 of 3 tests were negative, sterile speculum examination was repeated after 30 min of the first test. Test performance was calculated by comparing AmniSure results against final diagnosis at birth. Of 200 patients between 28 and 42 weeks gestation recruited for study, 31.5% (63/200) were preterm, 68.5% (137/200) term. Statistical analysis of data collected in the electronic database using SPSS version (Amnisure International LLC, 30 JFK Street, 4th Floor, Cambridge, MA 02138, USA).

Results: AmniSure rapid immunoassay, rapid method for diagnosis of ROM, has 100% specificity, 99.44% sensitivity (one false negative due to meconium and immediate cesarean section).

Conclusion: In comparison to nitrazine, pooling, ferning, AmniSure has almost 100% sensitivity, specificity.

Keywords: AmniSure, diagnosis, meconium, preterm, term rupture of membranes