What if your doctor has told you that you have too much amniotic fluid? What does that mean, and what do you do about it? Too much amniotic fluid is called polyhydramnios. Interestingly most people don't even know what amniotic fluid is. The fact of the matter is, it's fetal urine. Fetuses void and then swallow, and then void and then swallow. Normally the balance between the bladder emptying and fetal swallowing is about the same, so the amniotic fluid remains roughly static during the course of pregnancy, but not always. Sometimes fluid can accumulate in excess, now what could possibly cause that? Well, if the fluid in the amniotic cavity is a product of voiding and swallowing, then excess fluid can be a problem of either too much voiding, too little swallowing, or both. A well recognized cause of excessive voiding is diabetes. There are several causes of reduced swallowing. One of the common causes of reduced swallowing is obstruction at the level of the upper intestine, that can occur in the setting, for example, Down's Syndrome with duodenal atresia, or with esophageal atresia, or with a small jaw in certain genetic conditions. Too little swallowing can also be caused by failure of the nerves in the central nervous system to regulate the swallowing muscles appropriately, and that can happen in some genetic conditions, neuromuscular conditions like Neu Laxova or Pena Shokeir. If polyhydramnios is encountered during pregnancy it's important for your doctor to search for the underlying cause.