Amniotic Fluid Testing for PROM and pPROM

Early detection of amniotic fluid leaking during pregnancy is critical to preventing or managing complications such as fetal distress, umbilical cord prolapse, placental abruption and infection. An accurate and timely diagnosis is the first step to an effective intervention. Conversely, a false diagnosis can lead to unnecessary hospitalization, medication and premature induction of labor.

Clearly, there is a need for accurate, cost-effective testing for amniotic fluid leaks especially in cases of uncertain rupture. A current gold standard for diagnosis — amino dye infusion testing through amniocentesis — is expensive and requires specialized equipment and trained staff. This makes it impractical to administer in most cases. Fortunately, there are reliable and effective alternatives.

Rupture of Membrane Test Options

Alternatives to amnio dye infusion testing for leaking amniotic fluid include:

  • Visual inspection: In certain cases of PROM and pPROM, amniotic pooling will be visible in the posterior fornix during a sterile speculum exam. However, the accuracy of this testing is subjective, and in nearly half of all cases, membrane rupture will produce no visible symptoms.1 It should be noted that substances such as urine, semen are often mistaken for amniotic fluid and could lead to false positive results.
  • Nitrazine testing: Leaking amniotic fluid is considerably more alkaline than vaginal fluid. An abnormal pH profile, typically identified through nitrazine testing, can indicate that PROM has occurred. However, nitrazine testing is unreliable as several substances, including blood, semen and urine, can create false positives.
  • Ferning: The fern test can identify, via microscopy, the presence of sodium chloride in the vaginal fluid — often a sign of PROM or pPROM. However, fern testing requires both an invasive speculum exam to collect a sample, and a powerful microscope to analyze it.

Biomarker Testing for PROM and pPROM

In recent years, certain biomarkers of amniotic fluid have been identified that can be used to test for membrane rupture with greater ease and a higher degree of accuracy. AmniSure® identifies that presence of the placental alpha microglobulin (PAMG-1) protein, which can be used to diagnose PROM with ~99% accuracy, according to published data.2

Testing with AmniSure® is simple and non-invasive. Sample collection does not require a sterile speculum exam so any healthcare professional including nurses and midwives may collect the sample. Using a collection swab, a sample of vaginal fluid is collected. A test strip is then inserted into the sample, indicating the presence of PAMG-1 in minutes. ROM testing with AmniSure® can provide an accurate diagnosis of PROM or pPROM — saving time, money and resources, and preventing unnecessary hospitalizations.

  • Caughey, AB et al. Contemporary Diagnosis and Management of Preterm Premature Rupture of Membranes. Rev. Obstet. Gynecol. 2008;1(1):11–22.
  • AmniSure® ROM Test Package Insert


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