What You Need to Know About Amniotic Fluid
The amniotic fluid that surrounds your baby plays an important role in your baby's growth and development. This clear-colored liquid protects the baby and provides it with fluids. Your baby breathes this fluid into its lungs and swallows it. This helps your baby's lungs and digestive system grow strong. Your amniotic fluid also allows the baby to move around, which helps it to develop its 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 28-32 weeks of pregnancy. At that time you have about 1 quart of fluid. After that time, the level stays about the same until about 37-40 weeks, when your baby is considered full-term. After that, the level begins to decrease.
What You Need to Know About Oligohydramnios
Oligohydramnios (too little amniotic fluid) occurs in about 8 out of 100 of pregnancies. It is most common in the last trimester of pregnancy, but it can develop at any time in the pregnancy. About 1 out of 8 women whose pregnancies last 2 weeks past the due date develops oligohydramnios. This happens as amniotic fluid levels naturally decline.
Oligohydramnios is diagnosed with ultrasound. The causes of this condition are not completely understood. In fact, most pregnant women who develop oligohydramnios have no known cause.
The most important causes of oligohydramnios early in pregnancy are:
• Certain birth defects in the baby
• Ruptured membranes (breaks or tears in the sac that holds the amniotic fluid)
Birth defects involving the kidneys and urinary tract are the most likely causes of this problem. That's because babies with these birth defects produce less urine, which makes up most of the amniotic fluid. Some maternal health problems have also been linked with oligohydramnios. These problems include high blood pressure, diabetes, an autoimmune condition called system lupus erythematosus (SLE),and placental problems.
Oligohydramnios may affect you, your baby, and your labor and delivery in different ways. The effects depend on the cause, when the problem occurs, and how little fluid there is.
• In the first half of pregnancy, too little amniotic fluid may result in birth defects of the lungs and limbs. During this period, oligohydramnios increases the risk of miscarriage, preterm birth and stillbirth.
• When oligohydramnios occurs in the second half of pregnancy, it is linked to poor fetal growth.
• Near delivery, oligohydramnios can increase the risk of complications during labor and delivery.
Recent studies suggest that women with otherwise normal pregnancies who develop oligohydramnios probably need no treatment. Their babies are likely to be born healthy. Even so, your provider may want to watch you closely. When treatment is needed, the amniotic fluid may need to be replaced with an artificial substitute once the woman is in labor.
What You Can Do
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.
Women with high blood pressure, diabetes, lupus and placental problems are at increased risk for oligohydramnios. If you have any of these conditions, be sure to let your health care provider know.
If you have high blood pressure:
• Talk to your health care provider before pregnancy (or as soon as you think you are pregnant).
• Be sure any medications you are taking are safe during pregnancy
• Be sure your blood pressure is well controlled.
If you have oligohydramnios, be sure to eat a healthy and nutritious diet, drink lots of fluids (water is best), get plenty of rest, avoid smoking, and report any signs of preterm labor to your health care provider right away.
January 2007
