What Happens when a Pregnant Woman's Water Breaks

All pregnant women will have their water break before they deliver their baby. When women say "my water broke", they are referring to a rupturing of the thin, translucent membranes that cover the infant. These amniotic membranes allow the infant to float in a warm pool of amniotic fluid.

While all women will experience their water breaking, pregnant women should know that this event can happen in one of several ways. The safest way for water to break is spontaneously in the midst of a normal labor. This means that the pregnant woman is full term (at least 37 weeks gestational age) and that her cervix has already begun to dilate significantly.

In a normal labor, the water may break just prior to the period when contractions occur at regular intervals, or the water may not break until the woman is having regular contractions occurring at least every five minutes.

Some pregnant women who are full term but progressing slowly through their labor may not have a spontaneous rupture of membranes. In this case, the obstetrician may decide to rupture the membranes artificially to help the labor progress more appropriately.

The artificial rupture of membranes is done using a long, thin instrument with a tiny hook on the end. This is inserted through the cervix to break a hole through the amniotic membranes.

In other cases, a pregnant woman may be full term and have her water break before she has had a significant degree of cervical dilation or any regular contractions. This woman is not in true labor but has experienced a rupture of membranes. When the water breaks before a full term pregnant woman has actually begun to labor, the event is called premature rupture of membranes.

If a full term pregnant woman who has prematurely ruptured her membranes does not enter active labor on her own within 16 hours, labor will be induced using medications and other techniques. In some cases, antibiotics may be administered to protect both the mother and the infant.

There is another situation pregnant women should know about in regards to water breaking. This is the situation in which a pregnant woman's water may break before she is at a full term pregnancy. If the membranes have indeed ruptured before the infant is at full term, which is 37 weeks gestational age, then the condition is called preterm premature rupture of membranes.

Tests must be done to confirm the premature rupture of membranes in a pregnant woman who is not full term. The tests are done with a sterile speculum exam of the vagina. During the exam, the doctor will note any pooling of amniotic fluid in the posterior fornix of the vagina (the cavity behind the cervix) and/or amniotic fluid coming from the cervical opening.

The lab tests that may be done to confirm that the fluid is indeed amniotic fluid include:

-Ferning of the fluid on the glass slide when examined microscopically

-Nitrazine dye test (can give false positives if semen or blood is present)

-Fetal fibronectin levels greater than 50 ng/ml

A pregnant woman experiencing symptoms of normal water breaking, premature rupture of membranes or preterm premature rupture of membranes may experience a gush of fluid from her vagina or she may notice that she is slowly leaking a thin fluid. Water breaking is a normal part of pregnancy. All pregnant women should be aware of the various ways this event may occur in order to keep themselves and their baby safe and healthy.