Medline Plus states that amniotic fluid allows the fetus to move, helps the lungs develop, provides a heat buffer that keeps the fetus at a constant temperature and cushions the fetus. Additional functions reported by PregMed are aiding digestive system development, keeping the umbilical protected and preventing the amniotic sac from coming in contact with the fetus.
Medline Plus defines amniotic fluid as a clear to slightly yellow liquid. It completely surrounds a developing fetus and is contained within a protective structure known as the amniotic sac.
According to PregMed, amniotic fluid mostly consists of water but also contains dead skin cells and waste from the fetus. The fetus ingests the fluid and eventually releases it as waste. This keeps the fluid circulating and staying in motion, which is essential to the development of musculoskeletal tissues.
Medline Plus reports that the volume of amniotic fluid is at its peak near the 34th week of pregnancy at which time it measures 800 milliliters. A pregnancy in which the mother has excessive or too little amniotic fluid poses danger to the fetus. Too little fluid may result in a stillbirth or miscarriage, while excess fluid can cause membranes to burst prematurely or induce preterm labor.