The FDA is reminding clinicians that improper use of rupture-of-membranes (ROM) tests in pregnant women can lead to severe adverse events. The warning follows multiple reports of health complications — including 13 fetal deaths — associated with test misuse. The agency emphasized that ROM tests should not be used alone but rather should be part of an overall clinical assessment that may include testing for leaking amniotic fluid. Inaccurate results, including false-negatives, may occur

Both the timeframe in which testing occurs and the presence of blood, meconium, antifungal creams, or lubricants from vaginal exams can affect the results.

The FDA separately announced a recall for a single brand of ROM test (marketed as AmniSure) due to a malfunction that could impact how the results are interpreted.

Preterm prelabor rupture of membranes (PPROM) refers to rupture of fetal membranes prior to labor in pregnancies <370/7thsweeks. It occurs in 3 percent of pregnancies and is responsible for one-third of preterm births.

The diagnosis of PPROM is clinical, based on visualization of amniotic fluid coming out of the cervical canal/pooling in the vaginal fornix of a woman who presents with a history of leaking fluid. Laboratory tests (eg, Nitrazine, fern, AmniSure, Actim PROM, ROM Plus) and ultrasound are used for confirmation in cases of clinical uncertainty.

If PPROM is not obvious after visual inspection, the diagnosis can be confirmed by testing the pH of the vaginal fluid, which is easily accomplished with Nitrazine paper. Amniotic fluid usually has a pH range of 7.0 to 7.3 compared with the normally acidic vaginal pH of 3.8 to 4.2 and the normal acidic pH of urine of 5.0 to 6.0.