Pregnancy Information Childbirth Membrane Rupture

During pregnancy, the fetus is surrounded by amniotic fluid, which is in turn contained by a membrane sac. During labor, the membranes rupture, a process that is sometimes referred to as a woman’s “waters breaking.” If the amniotic fluid membranes rupture too early, pregnancy complications or preterm labor may occur.

The membranes may rupture themselves, or they may be ruptured to induce labor or increase the speed of delivery.

Membrane Rupture, Labor and Delivery

Rupture of the amniotic fluid membranes must occur for a successful labor and delivery. Until the membranes rupture, the fetus cannot enter the birth canal and labor cannot continue.

If a woman is lying down when the amniotic fluid membranes rupture, she may experience a sudden flow of amniotic fluid out of the vagina. If she is standing, rupture of the membranes may only produce a small leaking of amniotic fluid. This is because the fetus’ head plugs the birth canal and prevents a complete drainage of the fluid.

Premature rupture of the membranes may trigger labor before the pregnancy comes to term. Prior to 37 weeks, rupture of the membranes is call “preterm” rupture of the membranes. From week 37 to term if the membranes rupture in the absence of actual labor, the rupture is labeled “premature.”

Remember CAST

Contact your doctor or midwife when your membranes rupture. Be prepared to answer the following, abbreviated as CAST:

  • C – color of amniotic fluid
  • A – amount of fluid
  • S – smell/odor of fluid
  • T – time your water broke.

Rupture of Membranes and Infection

If the membranes rupture earlier than fifteen to twenty hours before labor begins, the risk of fetal or maternal infection increases.

Normal amniotic fluid is clear or amber colored. If the fluid is dark, green, smells bad, or contains blood, inform your doctor immediately.

A green or brown tint to the amniotic fluid is indicative of the presence of meconium (the first fetal stool), which can be dangerous to the baby if inhaled during pregnancy. The presence of meconium in the amniotic may indicate fetal distress.

Preterm Rupture of the Membranes

If the membranes rupture earlier than the 37th week of pregnancy, the condition is called “preterm rupture of the membranes.” Preterm rupture of the membranes may trigger premature labor and delivery. Between one-third to one-quarter of premature delivery cases are due to preterm rupture of the membranes.

Early rupture of the membranes places the fetus at risk for a premature delivery. In some cases, the membranes may rupture as early as three or four weeks prior to the expected date of delivery. Proper care and monitoring may allow the fetus more time to mature before labor and delivery. Although unlikely, in a small number of cases preterm rupture of the membranes leads to a stillbirth.

Treatment of Membrane Rupture

Treatment centers on hospitalized observation. If needed, antibiotics may be prescribed to guard against infections. If the membranes rupture before the fetus’ lungs develop, corticosteroids may be used to speed up lung maturation and reduce the risk of respiratory distress after delivery.

Risk Factors for Preterm or Premature Membrane Rupture

Premature or preterm rupture of the amniotic fluid membranes can happen during any pregnancy, but some factors increase the possibility. If a woman had preterm membrane rupture in a pregnancy she is likely to experience preterm membrane rupture in subsequent pregnancies.

Pelvic trauma, including pelvic surgery, also increases the risk of early membrane rupture.

Smoking increases the risk of early membrane rupture. Sexually transmitted diseases and other genital tract infections also raise the risk of membranes breaking early.


Beers, M.H.