What is Polyhydramnios?

Polyhydramnios refers to excessive amounts of amniotic fluid that accumulate in the uterus of a pregnant woman. Amniotic fluid protects the baby while in utero. Polyhydramnios, also called hydramnios, is normally rare, and most cases are mild and transient. Typically, polyhydramnios occurs in the second part of the pregnancy. Although polyhydramnios is generally mild, severe cases may cause concerning symptoms, such as difficulty breathing and early onset of labor.

Other symptoms of polyhydramnios may include inability to lie flat due to shortness of breath and swelling or edema in the abdominal wall area and lower extremities. In addition, hydramnios may cause a decrease in urinary production; this can be an ominous symptom because decrease in urinary output may signal a serious kidney problem. Symptoms are usually caused by pressure on the interior of the uterus and other organs.

Causes of polyhydramnios may include defects of the baby's central nervous system or gastrointestinal tract, diabetes during pregnancy, and anemia of the fetus. Anemia refers to a decrease in the number of red blood cells. Another cause of polyhydramnios may occur when the mother's and the baby's blood are incompatible. Many times, however, the cause of hydramnios cannot be determined.

Complications of excessive amniotic fluid may include early or preterm birth, high blood pressure and premature breakage of membranes, or water bag. Other complications may include excess or rapid fetal growth, heavy bleeding, and even stillbirth. Sometimes, a C-section may be required if it is determined the baby is in fetal distress. If the mother had polyhydramnios in the first half of her pregnancy instead of the second part, or if the fluid amount is excessive, she may have a higher incidence of complications.

Typically, diagnosis of hydramnios include an ultrasound, which is a medical imaging test that utilizes sound waves to capture images. Other medical testing may include amniocentesis, where amniotic fluid is obtained from the uterus and analyzed. Since maternal diabetes can be a risk factor in developing hydramnios, serum glucose testing may be employed to determine if the mother has diabetes.

Treatment for this condition may include draining the excess fluid and a prescription for medication. Certain medications reduce the volume of amniotic fluid and reduce urine production of the fetus, thereby reducing the amount of amniotic fluid. Some cases of hydramnios are very mild and require no special treatment. Mild cases may resolve on their own. If maternal diabetes is a contributing factor, hydramnios may resolve once blood glucose levels have been controlled.