The clinical significance of a positive Amnisure test in women with term labor with intact membranes

Abstract

Objective: The Amnisure ROM test is approved for the diagnosis of rupture of membranes (ROM). Yet, a fraction of patients with a positive test have intact membranes by sterile speculum examination. The objective of this study was to determine the clinical significance of this finding.

Methods: The study population consisted of four groups of nulliparous women at term: (1) not in labor without clinical evidence of ROM (n = 125); (2) in labor without clinical ROM with a negative Amnisure test (n = 56); (3) in labor without clinical ROM with a positive Amnisure test (n = 25); and (4) in labor with clinical ROM (n = 30). The Amnisure test was performed in cases without clinical ROM (Groups 1, 2 and 3).

Results: (1) The Amnisure test was positive more frequently in women in labor with intact membranes than in patients not in labor at term without ROM (30.9% (25/81 women) vs. 4.8% (6/125 women); p < 0.001); (2) patients in labor without clinical ROM with a positive Amnisure test had a significantly shorter admission-to-delivery interval than those in labor without clinical ROM with a negative Amnisure test (p < 0.05).

Conclusion: (1) A positive Amnisure test is present in about one-third nulliparous women at term presenting in labor with intact membranes; (2) patients with a positive Amnisure test had a shorter admission-to-delivery interval than those with a negative test.

Figures

FIGURE 1

Study population

FIGURE 2

Survival analysis of admission-to-delivery interval, according to the presence of clinical ROM and results of the Amnisure test™ (Group 2, in labor without clinical ROM with a negative Amnisure test™: median, 9.79 hours [range, 2.32-33.07]; Group 3, in labor without clinical ROM with a positive Amnisure test™: median, 6.88 hours [range, 1.18-15.98]; Group 4, in labor with clinical ROM: median, 5.58 hours [range, 1.80-33.47]). NS, Not significant