In every pregnancy the amniotic sac that surrounds the baby (also called the membranes or the bag of waters) must break before the baby can be born. This usually happens during labor, but in about 10% of pregnancies it occurs more than six hours before labor contractions begin. This is called premature rupture of membranes. When the membranes break before labor begins and before the 37th week of pregnancy, it is called preterm premature rupture of membranes or PPROM. This occurs in about 3% of pregnancies. When the membranes break before the 37th week but after labor has started, it is called preterm labor with subsequent membrane rupture -not PPROM. It's not always easy to distinguish between these two kinds of preterm labor because many women are not aware that they've started labor until their membranes rupture.
PPROM is a serious complication for three reasons:
- The amniotic fluid that normally surrounds and protects your baby may completely leak out of your vagina. The baby's umbilical cord, which delivers oxygen and nutrients and removes carbon dioxide and waste products from the baby, is normally suspended in and protected by the amniotic fluid. If the amniotic fluid is gone, the umbilical cord may get squeezed between the baby and the wall of the uterus. This can cause brain injury and even death to the baby. In a small number of cases, the umbilical cord drops out of the uterus into the vagina ( prolapsed umbilical cord ), causing serious problems for the baby-possibly even death.
- The amniotic sac keeps germs from getting into the uterus and amniotic fluid. If the uterus becomes infected ( chorioamnionitis ), your baby must be delivered immediately, regardless of how far along in the pregnancy you are. The baby can become infected with bacteria and other organisms from the vagina. Such infections can have serious consequences for you and your baby. Chorioamnionitis develops in 13 to 60% of patients with PPROM.
- If your water breaks very early in pregnancy (before 23 weeks), your baby's lungs may not develop properly. Amniotic fluid in the early part of pregnancy is needed to cause lung tissue to form. If there isn't fluid between 18 and 22 to 23 weeks, the lung tissue may never form. This problem, called pulmonary hypoplasia, occurs most commonly when the water breaks very early, around 18 weeks. If the water breaks during this period, the baby's limbs may also not develop normally. Babies need to be able to stretch and kick for their muscles and joints to develop properly.
What If I Have PPROM?
If you have PPROM, you and your doctor need to decide whether to deliver your baby immediately or to try to continue the pregnancy.