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Hydramnios, also called polyhydramnios, refers to an excessive amount of amniotic fluid in the womb during pregnancy. It is a rare condition that only affects about one percent of pregnancies annually. Hydramnios can occur when the woman's body produces too much fluid, or it may result from the baby's inability to swallow and process fluid properly. Babies are at risk of being born prematurely and with underdeveloped vital organs if the condition is not treated prenatally with specialized medication.
In normal amounts, amniotic fluid plays an essential role in fetal development. The fluid surrounding the fetus provides cushioning and protection from injury. In addition, a growing embryo needs to swallow and process relatively large amounts of amniotic fluid to protect itself against infection and encourage healthy lung, bone and muscle formation. Healthy fetuses recycle fluid by expelling it as urine and swallowing it again, keeping fluid levels near constant throughout development.
Doctors have identified many specific risk factors for hydramnios. A blockage in the fetus's gastrointestinal tract might prevent fluid from being swallowed and processed properly, leading to a buildup of fluid in the womb. A central nervous system or neuromuscular defect can also inhibit proper swallowing. Hydramnios can also occur in women carrying twins if one of the fetuses receives a disproportionate amount of blood and nutrients, causing the other to unsuccessfully process fluid. Excess fluid levels can also be related to a mother's health condition, especially in the case of uncontrolled diabetes, kidney problems and circulatory system disorders.
A fetus that is unable to swallow and process sufficient amounts of amniotic fluid is at risk of never fully developing lung tissue. Skeletal disorders such as dislocated hips and smaller than usual legs and arms are common. Babies are often born prematurely, adding to their developmental problems.
In most cases, hydramnios is noticed during routine ultrasounds and screenings during the third trimester of pregnancy. When high levels of amniotic fluid are detected, a doctor can conduct a more intensive ultrasound to carefully observe a fetus's anatomy. The physician looks for signs of abnormal lung and heart functioning, gastrointestinal blockages and an irregularly sized abdomen. The mother is also typically tested for diabetes and other conditions to help narrow the possible causes of hydramnios.
Once the condition has been diagnosed, the doctor can decide on the best course of treatment. Since premature delivery is likely, the doctor may order an expecting mother to enter a hospital earlier than usual. She may be given steroids in an effort to boost the development of her fetus's lungs before delivery. Additional medications are given to mothers to reduce urinary flow from fetuses, effectively lowering the total amount of amniotic fluid dispersed in the womb.
With early treatment, hydramnios often clears up before the baby is born. Since the infant may still be born prematurely and face developmental issues, it is essential for emergency specialists to attend the delivery. When experts are available to provide intensive care, babies and their mothers enjoy a very good prognosis.