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Prelabor Rupture of the Membranes (PROM)

(Premature Rupture of Membranes)


Julie S. Moldenhauer

, MD, Children's Hospital of Philadelphia

Reviewed/Revised Jul 2021 | Modified Sep 2022

Prelabor rupture of the membranes is the leaking of amniotic fluid from around the fetus at any time before labor starts.

  • After the membranes rupture, labor often soon follows.

  • If labor does not begin within 6 to 12 hours, the risk of infections in the woman and fetus increases.

  • If labor does not start soon after the membranes rupture and the pregnancy is 34 weeks or more and the fetus’s lungs are mature, labor is usually started artificially (induced).

  • If the pregnancy is less than 34 weeks and the fetus's lungs are not mature enough, the woman is usually hospitalized, monitored closely, and she is given corticosteroids to help the fetus's lungs mature and antibiotics to treat and prevent any infection that might trigger labor and/or harm the fetus.

  • If the pregnancy is less than 32 weeks, women may be given magnesium sulfate to reduce the risk of cerebral palsy.

Rupture of the membranes is commonly described as “the water breaks.” When the membranes break, the fluid within the membranes around the fetus (amniotic fluid) flows out from the vagina. The flow varies from a trickle to a gush. As soon as the membranes have ruptured, a woman should contact her doctor or midwife.

Did You Know...

  • As soon as their water breaks, pregnant women should contact their doctor or midwife.

Usually, the fluid-filled membranes containing the fetus rupture during labor. But occasionally in normal pregnancies, the membranes rupture before labor starts—prelabor rupture.

Prelabor rupture of the membranes may occur near the due date (at 37 weeks or later, when pregnancy is considered full term) or earlier (called preterm prelabor rupture if it occurs earlier than 37 weeks). If rupture is preterm, delivery is also likely to be too early (preterm Preterm Labor Labor that occurs before 37 weeks of pregnancy is considered preterm. Babies born prematurely can have serious health problems. The diagnosis of preterm labor is usually obvious. Measures such... read more ).

Regardless of when prelabor rupture occurs, it increases the risk of problems such as

Infection of the uterus can cause a fever, a heavy or foul-smelling vaginal discharge, or abdominal pain.

  • Lung problems

  • Bleeding in the brain

  • Possibly death

If the pregnancy is less than 24 weeks when the membranes rupture, the fetus's limbs may be deformed.

After the membranes rupture, contractions usually begin within 24 hours when the woman is at term but may not start for 4 days or longer if rupture occurs between 32 and 34 weeks of pregnancy.

Diagnosis of PROM

  • Examination of the vagina and cervix using a speculum

Using a speculum to spread the walls of the vagina, the doctor or midwife examines the vagina and cervix (the lower part of the uterus) to confirm that the membranes have ruptured and to estimate how much the cervix has opened (dilated).

If doctors see amniotic fluid leaking from the vagina, they assume the membranes have ruptured.

If prelabor rupture of the membranes is diagnosed and the fetus can survive outside the uterus, the woman is usually admitted to a hospital so that the status of the fetus can be determined.

Treatment of PROM

  • If the pregnancy is 34 weeks or more, usually artificial starting (induction) of labor

  • If the pregnancy is less than 34 weeks, usually rest, close monitoring usually in the hospital, antibiotics, and sometimes corticosteroids

  • If the pregnancy is less than 32 weeks, usually magnesium sulfate to prevent bleeding in the brain and problems with development of the newborn's brain

Doctors must balance the risk of infection in the uterus and in the fetus when delivery is delayed against the problems that may occur when a newborn is premature. Generally, a doctor or certified nurse midwife does the following:

Sometimes doctors analyze a sample of amniotic fluid to determine how mature the fetus's lungs are. The sample may be taken from the woman's vagina or by amniocentesis Amniocentesis Prenatal testing for genetic disorders and birth defects involves testing a pregnant woman or fetus before birth (prenatally) to determine whether the fetus has certain abnormalities, including... read more . In amniocentesis, a doctor inserts a needle through the wall of the abdomen into the amniotic fluid and withdraws a sample from the membranes around the fetus

If the fetus is in severe distress or the uterus is infected, labor is usually induced and the baby is delivered regardless of the length of the pregnancy.

If labor needs to be delayed

If the pregnancy is less than 34 weeks, labor is delayed. The woman is advised to rest and to limit her activities as much as possible. She may be hospitalized so that she can be monitored closely. Her blood pressure, temperature, and pulse rate are usually recorded at least 3 times daily. An increase in temperature or pulse rate may be an early sign of infection. If an infection develops, labor is promptly induced and the baby is delivered.

Antibiotics are begun when rupture has been confirmed. Usually, antibiotics (such as erythromycin, ampicillin, and amoxicillin) are given intravenously, then by mouth for several days. Antibiotics delay the start of labor by treating infections that can trigger labor, and they reduce the risk of infection in the newborn.

If the membranes rupture between the 24th and 34th week of pregnancy, corticosteroids are given to help the fetus’s lungs mature.

Doctors may also give women corticosteroids if the membranes rupture

  • Between 34 and 37 weeks of pregnancy if women are at risk of preterm delivery and have not been given any corticosteroids earlier in the pregnancy

  • Starting at 23 weeks of pregnancy if women are at risk of preterm delivery within 7 days

If the pregnancy is less than 32 weeks, women may be given magnesium sulfate intravenously. This drug appears to substantially reduce the risk of bleeding in the newborn's brain and the resulting problems with development of the newborn's brain, such as cerebral palsy.

Drugs Mentioned In This Article

Generic Name Select Brand Names
A/T/S, Akne-mycin, E.E.S., Emcin Clear , EMGEL, E-Mycin, ERYC, Erycette, Eryderm , Erygel, Erymax, EryPed, Ery-Tab, Erythra Derm , Erythrocin, Erythrocin Lactobionate, Erythrocin Stearate, Ilosone, Ilotycin, My-E, PCE, PCE Dispertab , Romycin, Staticin, T-Stat
Amoxil, Dispermox, Moxatag, Moxilin , Sumox, Trimox
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