Which of the following compounds contributes to amniotic fluid?

• A. Placental hormones
• B. Blood plasma
• C. Fetal urine
• D. Amniotic sac tissue

Answer: (C)

Fetal urine is indeed a significant contributor to amniotic fluid. Amniotic fluid serves various critical functions during pregnancy, including cushioning the fetus, allowing for movement, and helping to regulate temperature.

As the fetus develops, it begins to produce urine around the 12th to 16th week of gestation. This urine is released into the amniotic sac, where it becomes a major component of the amniotic fluid. It is estimated that fetal urine contributes a substantial portion of the total volume of amniotic fluid in the later stages of pregnancy, highlighting the role of the fetal kidneys in both fluid balance and waste excretion during gestation.

Other choices, while related to pregnancy and the environment of the fetus, do not directly contribute to the composition of amniotic fluid in the same manner as fetal urine. Therefore, recognizing the specific role that fetal urine plays helps in understanding the dynamics of amniotic fluid production and its importance to fetal development.