Final answer:
Amniotic fluid serves to protect and cushion the fetus, allows for freedom of movement, facilitates lung and digestive system development, and can be used in prenatal genetic diagnosis.
Step-by-step explanation:
One of the functions served by amniotic fluid is to cushion the developing baby, protecting it from trauma and allowing for freedom of movement which is vital for muscular and skeletal development. This fluid surrounds the embryo or fetus in the amniotic sac, playing a critical role in its overall development. As the fetus grows, it starts to 'breathe in' and 'swallow' the amniotic fluid, which is important for the development of the lungs and the formation of the first stools, known as meconium. Additionally, analysis of amniotic fluid can provide insights into the child's genetic health since it contains fetal cells, which can be examined for genetic defects.
Early in pregnancy, amniotic fluid primarily consists of a filtrate of maternal plasma. By approximately the eighth week, as the fetal kidneys begin to function, the composition of the fluid changes, incorporating fetal urine. The volume of amniotic fluid is at its peak around the 34th week of pregnancy and starts to decrease closer to birth. Aside from cushioning and facilitating movement, amniotic fluid also helps in maintaining a stable temperature for the fetus and allows for the transfer of nutrients and gases through the placenta and umbilical cord.