What is Polyhydramnios?

Polyhydramnios is the condition of having too much amniotic fluid. Doctors can measure the amount of fluid through a few different methods, most commonly through amniotic fluid index (AFI) evaluation or deep pocket measurements. If an AFI shows a fluid level of more than 25 centimeters (or above the 95th percentile), a single deep pocket measurement of <8, or a fluid level of 2000mL or more, then a diagnosis of polyhydramnios would be made. About 1-2% of pregnant women have too much amniotic fluid. Most of these cases are mild, with only slightly elevated levels.

Congenital defects – The higher the fluid level, the increased chance of a congenital defect. These birth defects hinder swallowing, which can prohibit ingestion of the amniotic fluid, resulting in build up of fluid. Other birth defects could also include intestinal tract blockage or neurological abnormalities.
Rh Factor – As screening for the Rh factor has increased, this is no longer a common cause of elevated fluid levels.
Maternal Diabetes – Experts have found some correlation between diabetes and too much amniotic fluid.
Twin-to-twin transfusion syndrome – This is a complication that can affect identical twin pregnancies. This syndrome is when one baby gets too much blood flow and the other too little due to connections between blood vessels in their shared placenta.
Unknown Reasons – According to the Center for Maternal Fetal Medicine, about 65% of cases of polyhydramnios are due to unknown causes.

Most cases of polyhydramnios are mild and result in few, if any, complications. Those with higher levels of fluid could experience one or more of the following risks:

Many cases of polyhydramnios are easily treated and do not result in complications if the pregnancy is monitored closely. Monitoring would include frequent sonograms measuring growth, biophysical profile and fetal assessment. Other treatments could include: