Diagnosis of premature rupture of the membranes by the identification of alpha‐feto‐protein in vaginal secretions

Premature rupture of membranes (PROM) is sometimes difficult to diagnose. This report proposes the use of alpha-feto-protein (AFP) values in vaginal secretions for diagnostic tests. Our investigation took place in two separate phases. The first phase validated the AFP test using an immuno-enzymatic assay method and determined a threshold value from a sample of 167 female patients (Group 1: 133 patients with an extremely low probability of PROM, and Group 2: 54 patients with confirmed PROM). In the second phase the test was applied to a sample of 145 female patients (Group 3) with suspected, but unconfirmed, PROM. Results from alpha-feto-protein (AFP) evaluation were compared with data obtained from clinical, echographic and other tests. The positive/negative threshold adopted was an AFP concentration of 30 micrograms/l. For the two first groups, 1 and 2, sensitivity and specificity was in the 98% to 99% confidence level. For Group 3, sensitivity and specificity results at the 30 micrograms/l threshold value were 94.5% and 95.4% respectively. Quantitative measurement of AFP determined by immuno-enzymatic assay of vaginal secretions with a threshold of 30 micrograms/l is a reliable, simple and rapid diagnostic test. Results obtained are significantly better than the measurement of pH, the determination of prolactin, and more practical than diamino-oxidase (DAO) assays.