When a pregnant woman has polyhydramnios, the level of amniotic fluid surrounding her baby is too high. To understand why this can be a problem, it’s important to first understand the basics of amniotic fluid.
The amniotic fluid that surrounds your baby plays an important role in her growth and development. This clear-colored liquid protects the baby and provides her with fluids. Your baby actually breathes this fluid into her lungs and swallows it. This helps her lungs and digestive system grow strong. Your amniotic fluid also allows your baby to move around, which helps her to develop her muscles and bones.
The amniotic sac that contains your baby begins to form about 12 days after conception. Amniotic fluid begins to form at that time, too. In the early weeks of pregnancy, amniotic fluid is mainly made up of water supplied by the mother. After about 12 weeks, your baby’s urine makes up most of the fluid. The amount of amniotic fluid increases until about 36 weeks of pregnancy. At that time you have about 1 quart of fluid. After that time, the level begins to decrease.
Polyhydramnios (too much amniotic fluid) occurs in about 1 out of 100 of pregnancies. Most cases are mild and result from a slow buildup of excess fluid in the second half of pregnancy. But in a few cases, fluid builds up quickly as early as the 16th week of pregnancy. This usually leads to very early birth.
Polyhydramnios is diagnosed with ultrasound. Medical experts do not fully understand what causes this condition. In about half of cases, the cause is not known. Here are some of the known causes:
- Birth defects in the baby that affect the ability to swallow. Normally, when the fetus swallows, the level of amniotic fluid goes down a bit. This helps to balance out the increase in fluid caused by fetal urination.
- Heart defects in the baby
- Diabetes during pregnancy
- Infection in the baby during pregnancy
- Blood incompatabilities between the pregnant woman and the fetus (examples:
- Rh or Kell disease)
Women with mild polyhydramnios may have few symptoms. Women with more severe cases may have discomfort in the belly and breathing problems. That’s because the buildup of fluids causes the uterus to crowd the lungs and the organs in the belly.
Polyhydramnios may increase the risk of pregnancy complications such as:
- Preterm rupture of the membranes (PROM) (breaks or tears in the sac that holds the amniotic fluid)
- Premature birth
- Placental abruption (The placenta peels away from the uterine wall before delivery.)
- Poor positioning of the fetus
- Severe bleeding by the mother after delivery
The best thing you can do is to go to all your prenatal care appointments. Your health care provider can monitor the size of your belly and how much amniotic fluid is in your womb. If you have a problem, your provider can take steps to help prevent complications in you and your baby.
If you have diabetes, talk to your health care provider about your increased risk of polyhydramnios.
If your health care provider thinks you might have polyhydraminos, you will probably need extra monitoring during your pregnancy. In many cases, polyhydramnios goes away without treatment. Other times, the problem may be corrected when the cause is addressed. For example, treating high blood sugar levels in women with diabetes often lowers the amount of amniotic fluid. Other treatments include removing some amniotic fluid or using medication to reduce fluid levels.