Amniotic fluid

Amniotic fluid is a clear, yellowish liquid that surrounds the fetus during pregnancy. It is contained in the amniotic sac.

Composition

Amniotic fluid is primarily water, but it also contains important substances such as nutrients, hormones, and antibodies. The composition of the fluid changes over the course of pregnancy. Early in pregnancy, it is similar to the mother's plasma. As the fetus grows and produces urine, the fluid becomes more like urine.

Functions

Amniotic fluid serves several important functions. It provides a cushion that protects the fetus from physical impacts. It also allows the fetus to move and develop muscles and bones. The fluid helps regulate temperature and provides a medium for the exchange of nutrients, water, and biochemical products between mother and fetus.

Abnormalities

Abnormalities in the amount of amniotic fluid can indicate problems with the pregnancy. Too much fluid, a condition known as polyhydramnios, can indicate fetal abnormalities or maternal diabetes. Too little fluid, known as oligohydramnios, can indicate problems with the placenta or fetal kidneys.

Diagnostic procedures

Amniotic fluid can be sampled for diagnostic purposes in a procedure known as amniocentesis. This procedure can detect genetic abnormalities and infections. It can also assess the maturity of the fetus's lungs.

See also

• Amniotic sac
• Amniocentesis
• Polyhydramnios
• Oligohydramnios

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  Human fetus 10 weeks with amniotic sac
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  Amniocentesis tubes