Every expectant mother anxiously anticipates the time when her “water” breaks, an event that signifies the sudden rupture of the membranes surrounding your baby and usually heralds the onset of labor. But even if you are nearing your due date, it may take several hours after your water breaks before labor begins. If your water breaks before your pregnancy has reached term, it could be days or weeks before your contractions begin. Regardless of how far you are from your due date, notify your obstetrician or midwife immediately if you notice water leaking from your vagina.
Premature Rupture of Membranes
Premature rupture of membranes happens when your water breaks before the onset of labor. According to the authors of a study published in the 2011 issue of “BMC Pregnancy and Childbirth,” PROM occurs in about 8 percent of pregnancies, usually after the 37th week of pregnancy.
Approximately 3 in 100 women will experience PROM before their 37th week of pregnancy, which is called preterm PROM. Preterm PROM causes 1/3 of premature births and may lead to other complications.
Onset of Labor
Most women who experience PROM after their 37th week of pregnancy will start having contractions soon afterward. Around 95 percent of expectant mothers who break their water at term will deliver within 1 day, according to a February 2006 review in “American Family Physician.” In contrast, when PROM occurs between 16 and 26 weeks, labor is usually delayed, with about 1/2 of women delivering within 1 week and more than 20 percent waiting at least 4 weeks before they deliver. When PROM occurs before 34 weeks, your doctor may prescribe medications in an effort to delay delivery and prevent complications associated with PROM.
In addition to premature delivery, PROM can be associated with other problems. Loss of amniotic fluid can alter the fetus’ position, which could make delivery more difficult. PROM also heightens the risk for fetal neurological injuries, umbilical cord compression and early separation of the placenta from the uterine wall. An opening in the membranes around your baby may allow the umbilical cord to protrude into your birth canal, where it can become pinched and deprive your baby of its blood supply. Bacteria can also enter this opening and cause an infection called chorioamnionitis, which can be life-threatening for both a mother and her unborn baby.
If you think you have broken your water but your contractions have not started, your doctor may perform several tests to determine whether your membranes have ruptured. One simple test involves placing a sample of your vaginal fluid on a special type of paper that turns blue in the presence of amniotic fluid. Your doctor may also examine your cervix with a speculum to detect any leaking fluid and determine if your cervix is dilating.
If these tests don't give the full story, ultrasound examination or amniocentesis may be needed. In this latter test, a fine needle is inserted through your abdomen into your uterus and a small amount of harmless dye is injected. If the dye leaks from your cervix, it confirms PROM.
Treatment for PROM is based on your stage of pregnancy and the maturity of your baby’s lungs. If your pregnancy has progressed beyond 34 weeks, your doctor may induce labor, as this has been shown to be the safest course for both mothers and infants when PROM occurs near term. If PROM occurs between 32 and 34 weeks, labor may be induced if tests show your baby’s lungs are mature.
When PROM happens before 32 weeks or if your baby’s lungs are immature, your doctor may prescribe medications to prevent uterine contractions, antibiotics to prevent infection and corticosteroids to hasten development of your baby’s lungs. In these situations, prolonging pregnancy will improve your baby’s chances for survival and lessen the likelihood of complications.