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Water Breaking During Pregnancy

Thanks to the movies, many people think that the first sign of labor is when the water bag breaks. Furthermore, as soon as the bag breaks, the lady on the big screen starts to scream that the baby is coming! This is the Hollywood version of childbirth. It is so pervasive a belief that many women become concerned when they begin to go into labor and they are still waiting for their water bag to break.

Time for a reality check. Most labors begin without the water bag breaking. Fewer than 10 percent of expectant mothers will break their water bag early in labor, before arriving at the hospital. Unfortunately, up to 33 percent of these women delay contacting their healthcare providers because their water hasn’t broken. The truth is that many women have their water broken for them at the hospital, or their water breaks after they are already in active labor.

When Will My Water Break?

The “water” we’re talking about is the amniotic fluid, which surrounds the baby in the membranous amniotic sac throughout the pregnancy. The outer layer of the sac is called the chorion. The inner layer is called the amnion. So the membranes are actually composed of two thin layers of tissue. The membranes are thin, but very strong and stretchable. It takes a lot of pressure to cause them to break, but a tiny nick from a sharp instrument will do it too, and this is how the doctor “breaks the water bag” in the hospital. Mother Nature’s process is somewhat mysterious, and is thought to involve enzymes, bacteria, and/or hormones, but we do not really know exactly how she does it.

The chorion is strengthened by collagen, a fibrous connective tissue also found in ligaments, cartilage, and tendons. Toward the end of the pregnancy the amount of collagen begins to decrease, which makes the chorion weaker. When the water bag breaks, the amniotic fluid will usually gush out for a moment, followed by a steady leak or trickle.

Some women report hearing a popping sound right before their water breaks. Other women experience symptoms such as trickling or wetness in the perineal area. Some women confuse amniotic fluid leakage with vaginal fluid, which is known to increase toward the end of a pregnancy.

How Will I Know if My Water Breaks?

If your water breaks, you may feel a rush of water as the amniotic fluid pools in the vagina. A steady stream of amniotic fluid usually continues to leak out after the initial rush of water. There are no over-the-counter tests you can purchase to see if the “water” is vaginal discharge or amniotic fluid. Only a doctor can test the fluid to determine whether or not your water has broken.

After you arrive at the hospital the doctor will test your fluid one of two ways; by placing the fluid on nitrazine paper to test the pH level of the fluid (vaginal fluid is acidic, but amniotic fluid is alkaline), or by placing the fluid under a microscope to look for the fern-like appearance it presents when it dries.

What Should I do if My Water Breaks?

The first thing you should do is grab a pen and paper. Write down the time your water broke, the color and appearance of the fluid, the estimated amount that came out, and anything else that is unique about it. Then call your doctor immediately. He or she will probably want you to head to your birthing location to prepare for labor. If you haven’t packed a hospital bag, now would be a good time. You shouldn’t worry about contacting family and friends right away, as the staff can usually assist you with that once you’ve arrived at the hospital.

Once you’re in the care of your healthcare provider, he or she will determine whether or not your water has broken. If you are full term, your doctor will probably induce labor if it doesn’t begin within 12–24 hours.

When Should I Contact My Doctor?

If you begin to experience any form of leakage toward the end of your pregnancy you should contact your doctor. It is possible that there has been a rupture in your amniotic sac. A rupture or break in your sac can cause infection. Labor usually begins within 24 hours of a woman’s water breaking, so it’s important that you seek medical attention if this happens.

[Page updated October 2014]