Why Does Water Break for Some Pregnant Women & Not for Others?

In the movies, labor is usually preceded by a dramatic and public breaking of the water, but in real life, only a very small percentage of women experience their water breaking before they go into labor. So if you're nervous about your water breaking while you're waiting in line at the supermarket or giving a big presentation at the office, you can relax -- the chances of that happening are fairly slim.

The Facts

The "water" that breaks when you go into labor is actually your amniotic sac, a protective membrane full of fluid that cushions your growing baby, gives him room to move around and helps block any vaginal infections you might get during pregnancy from reaching your baby, explains the "Journal of Midwifery and Women's Health." Though every woman who is pregnant has an amniotic sac, only about 10 percent of pregnant women have their water break before their labor contractions start, according to KidsHealth.org. In other words, nearly 90 percent of women won't have their water break until they are in serious labor.

Causes

The reason the amniotic sac ruptures before or during labor isn't clear, but it's probably part of your body's process of preparing for labor, explains WhatToExpect.com, the pregnancy and parenting information website that supplements the "What to Expect When You're Expecting" pregnancy book. Usually, your contractions will increase in intensity and duration once your water breaks, but it may take up to 48 hours for labor to begin. Most doctors will induce labor after 48 hours if it hasn't started naturally because of the increased risk of infection after your water breaks, explains MayoClinic.com. Sometimes, your water may not break at all, and your doctor will need to manually rupture the membrane.

Considerations

Sometimes, your water may break without you realizing what's happening, according to MayoClinic.com. That's because your water doesn't always break in a big gush -- sometimes it's more like a slow trickle that can bear a strong resemblance to urine. Since many women are in and out of the bathroom frequently during the final month of pregnancy, a slow break of the water may seem like par for the course. If you think your water has broken, call your health care provider immediately, even if you're not positive.

Warning

Once your water breaks, you should call your health care provider immediately, especially if your due date is still more than three weeks away. After your water breaks, don't have sex or insert anything -- including tampons -- into your vagina. If your amniotic fluid is yellowish, greenish or brownish, or if it has a funny smell, let your health care provider know immediately.