Amniotic fluid is a clear, pale yellow liquid that surrounds and protects a developing fetus during pregnancy. It is contained within the amniotic sac, which forms in the early stages of pregnancy. This fluid plays a crucial role in cushioning the fetus, allowing for movement and growth, and helps maintain a stable temperature. The fluid is composed mainly of water, but it also contains nutrients, hormones, and antibodies. As the pregnancy progresses, the volume of amniotic fluid increases, peaking around the 34th to 36th week. After this point, the amount may gradually decrease until birth.