Hydramnios is a condition characterized by too much amniotic fluid around the developing fetus during pregnancy. It is also known as polyhydramnios, and is classified under amniotic fluid disorders of pregnancy. It can occur at any stage, though more frequently seen during the later stages and last trimester.
Most of the times, the condition is benign and is caused due to a temporary disruption in the normal secretion of the amniotic fluid by the protective membranes, and resolves on its own. The pathophysiology behind this temporary disruption is still unknown. In few cases, it may be more severe. Various complications can arise due to such excessive secretion of amniotic fluid.
These include pressure on the developing fetus causing restricted growth and development, premature rupture of membranes, preterm labor and premature birth of low-birth weight babies. About 4% of pregnant women develop hydramnios. The risk is higher in case of twin or multiple pregnancies and in mothers with diabetes. Such a high fluid accumulation may also act as an indicator that everything may not be normal with the baby. It may be due to some gastrointestinal problems in the fetus or improper development of the fetal nervous system.
It may also be seen due to reduced swallowing reflex of the fetus, as babies in the womb typically do swallow some amount of the amniotic fluid.
There are various signs and symptoms associated with the condition which a mother should look for. These include feeling of heaviness in the lower abdomen, sluggish fetal movements, inability to feel the fetal movements as conspicuously due to too much cushioning with the amniotic fluid, swelling of the legs and feet, breathlessness and also possible uterine contractions.
Also your doctor has methods of checking for the normal levels of amniotic fluid around your developing baby. This can be done usually with an ultrasound machine which measures if the amount of amniotic fluid is low or high. Also the fundal height is measured- this is the distance from the top of the mother’s uterus to the top of the pubic bone in centimeters. If more than normal, it may again be an indication for polyhydramnios.
Most of the times, there is no intervention required. Your doctor may suggest you to take adequate bed rest and schedule regular follow-ups for you. At the follow-up visit, again through ultrasound or fundal height measurement, he will keep a check over the amniotic fluid levels. In case the levels do remain high, or become worse, then a therapeutic amniocentesis may be suggested.
This includes insertion of a long thin tube into the uterus through the cervix and aspiration of the excess amount of amniotic fluid. This helps to reduce the intra-uterine pressure and the associated complications. Once the amniotic fluid levels are better controlled, it is also necessary to keep monitoring the fetal development, because as stated before, hydramnios can be due to some fetal abnormalities. Since hydramnios puts the expecting mother at a risk for pre-term membrane rupture and preterm labour, immediately inform your doctor if there is any leaking of amniotic fluid or your water breaks before your estimated due date.