Polyhydramnios is the presence of excessive amniotic fluid surrounding the unborn infant.
Amniotic fluid is a clear, slightly yellowish liquid that surrounds the unborn baby (fetus) during pregnancy. It is contained in the amniotic sac.
While in the womb, the baby floats in the amniotic fluid. Amniotic fluid surrounds and cushions the infant throughout development. The amount of amniotic fluid is greatest at around 34 weeks into the pregnancy (gestation).
The amniotic fluid constantly moves (circulates) as the baby swallows and "inhales" the fluid, and then releases or "exhales" the fluid through urine.
The amniotic fluid helps:
Polyhydramnios can occur if the fetus does not swallow and absorb amniotic fluid in normal amounts. This can happen due to:
Polyhydramnios may also be related to increased fluid production, which occurs with:
Sometimes, no specific cause for polyhydramnios is found.
This condition is discovered during pregnancy. You may have noticed that your belly is getting large very quickly. You doctor or nurse measures the size of your uterus at every visit.
If your uterus is growing faster than expected, or it is larger than normal for your baby's gestational age, the doctor or nurse may:
If the health care provider finds a fetal abnormality (birth defect), you may need an amniocentesis to test for a genetic defect.
Women with polyhydramnios are also more likely to go into labor early. Mild polyhydramnios that shows up in the later part of pregnancy does not often cause serious problems. More severe polyhydramnios may be treated with medications or by having extra fluid removed.
The baby will be delivered in a hospital with specialists who can provide immediate evaluation and treatment.