hydramnios /hīdram″nē·əs/ [Gk, hydor + amnos, lamb’s caul] , an abnormal condition of pregnancy characterized by an excess of amniotic fluid. It occurs in less than 1% of pregnancies and is diagnosed by palpation, ultrasound, or radiographic examination. It is associated with maternal disorders, including toxemia of pregnancy and diabetes mellitus, and some fetal disorders, including anomalies of the GI tract, respiratory tract, and cardiovascular system, which may interfere with normal exchange of amniotic fluid. Fetal hydrops and multiple gestation are also associated with the condition. The incidence of premature rupture of the membranes, premature labor, and perinatal mortality is increased. Periodic amniocentesis may be necessary. Also called hydramnion, polyhydramnios. Compare oligohydramnios.
