Diagnosis of ruptured fetal membranes: Clinical study and review of the literature

The pertinent literature relating to the laboratory diagnosis of ruptured fetal membranes has been reviewed. Vaginal aspirates from 100 consecutive patients in labor were submitted to a battery of six tests in an attempt to facilitate the clinical recognition of membrane rupture. The condition of the membranes at delivery was used as the basis for determining the accuracy of the laboratory tests. It was obvious that the optimum time to obtain a vaginal specimen was within 2hours of presumed rupture. In selecting a spectrum of tests to be employed in doubtful instances of membrane rupture, it was determined that a combination of any three of the following (careful history, the nitrazine pH test, the amniotic fluid crystallization test, and/or the Nile blue stain) will produce accuracy of diagnosis approximating 93 per cent.