Preterm premature rupture of membranes (pPROM)

Before a baby is born, the amniotic sac breaks open, causing amniotic fluid to gush out or, less commonly, to slowly leak. When this happens before contractions start, it is called premature rupture of membranes (PROM). PROM can occur at any time during pregnancy.

When PROM occurs before 37 completed weeks of pregnancy, it usually leads to preterm labor. You may hear this early PROM referred to as preterm premature rupture of membranes, or pPROM.

PROM is often unexpected, and the cause is often difficult to identify. Known causes of PROM include:

• Uterine infection, which is a common trigger of PROM.
• Overstretching (distension) of the uterus and amniotic sac. Multiple fetuses or too much amniotic fluid (polyhydramnios) are common causes of distension.
• Trauma, as from a motor vehicle accident.

Course of pPROM

Preterm labor usually begins shortly after pPROM occurs. Sometimes, when a slow leak is present and infection has not developed, contractions may not start for a few days or longer. Generally, the later in a pregnancy PROM occurs, the sooner the onset of labor. Labor begins:¹

• Within 24 hours in 50% of pPROM cases.
• Within 7 days in 75% to 90% of pPROM cases.

On occasion, a leak high up in the amniotic sac may reseal itself so that preterm labor does not start or subsides.

In rare cases, a pregnancy can be carried to term if pPROM occurs in the second trimester.

Standard treatment for pPROM

Standard treatment for pPROM includes antenatal corticosteroid medications, which are used to speed up fetal lung maturity at or before 34 weeks of pregnancy.

Other treatment for pPROM

Other treatment for pPROM may include:

• An observation period.
• Antibiotics, given to treat or prevent amniotic fluid infection.
• Amniocentesis, which is sometimes used to check for infection in the uterus.
• Starting (inducing) labor with medication if labor does not start naturally. This is meant to speed up delivery and reduce the risk of infection. Labor can be induced if there is strong evidence that the fetus's lungs are mature enough, or if you have an infection.

Controversial treatment for pPROM

After amniotic membranes have ruptured, tocolytic medication is less effective in slowing or stopping preterm labor contractions. However, tocolytic medication is sometimes used to delay a preterm birth long enough for antibiotics and antenatal corticosteroid medication to work (24 hours) or long enough to transport the mother to a hospital that has a neonatal intensive care unit (NICU).²

Citations

1. Dyson DC, et al. (1998). Monitoring women at risk for preterm labor. New England Journal of Medicine, 338(1): 15–19.

2. American Academy of Pediatrics and American College of Obstetricians and Gynecologists (2002). Obstetric and medical complications. In Guidelines for Perinatal Care, 5th ed., pp. 163–185. Washington, DC: American Academy of Pediatrics, American College of Obstetricians and Gynecologists.