Rupture of the membranes
During pregnancy, your membranes break (rupture) when a hole or tear develops in the fluid-filled bag (amniotic sac) that surrounds and protects the fetus. The rupture of the membranes is also called “breaking of the waters.”
Your membranes can break by themselves (spontaneous rupture of the membranes), or they may be ruptured by the doctor or nurse-midwife to start or speed up labor (artificial rupture of the membranes). The spontaneous rupture of the membranes most often happens once active labor has started, not prior to the start of labor.
Your contractions may get stronger after your membranes rupture.
A large gush of fluid usually follows the rupture of the membranes. The uterus continues to produce amniotic fluid until the baby's birth, so you may continue to feel some leaking, especially right after a hard contraction (tightening of the muscles of the uterus).
Spontaneous rupture of the membranes
Sometimes it is hard to tell if your membranes have ruptured. As you approach your due date, your uterus puts increasing pressure on your bladder. A strong Braxton Hicks contraction or sneeze can cause some leakage of urine. This is sometimes mistaken for a rupture of the membranes.
If you are lying down when your membranes break, you are more likely to experience the rupture as a gush of liquid. If it happens when you are standing up, it's more likely to be just a trickle because the baby's head gets pushed down against the cervix and acts like a cork when you stand.
If you believe your membranes have ruptured:
- Contact your health professional. Your health professional may want to evaluate you as soon as your membranes rupture.
- Avoid letting anything enter your vagina. Do not have sexual intercourse or flush the vagina with fluid (douche).
You can also go to the place you have selected for the delivery of your baby. The health professionals there will test the drainage to determine if it is amniotic fluid.
Amniotic fluid is normally a cloudy-white to an amber-straw color. Let your health professional know if the leaking fluid is:
- Dark or greenish. Meconium (from a baby's first bowel movement) may be present.
- Foul-smelling. This could be a sign of infection in the uterus.
- Bloody. Small streaks of blood are normal, but if the entire fluid is stained with blood, it could be a sign of a problem with the placenta.
Artificial rupture of the membranes to induce labor
To start (induce) or speed up labor, the health professional may rupture your membranes. This should only be done after your cervix has started to open (dilate) and the baby's head is firmly descended (engaged) in your pelvis. If the membranes are ruptured too early, there is a risk of the umbilical cord slipping down around or below the baby's head (cord prolapse). If the cord gets squeezed between the baby's head and the pelvis bones, the blood supply to the baby may be decreased or stopped.
To rupture your amniotic sac (amniotomy), your health professional inserts a sterile plastic device into your vagina; the device may look like a long crochet hook, or it may be a smaller hook attached to the finger of a sterile glove. The hook is used to pull gently on the amniotic sac until the sac breaks. This procedure is usually not painful. A large gush of fluid usually follows the rupture of the amniotic sac. The uterus continues to produce amniotic fluid until the baby's birth, so you may continue to feel some leaking, especially right after a hard contraction.