Question

The major contribution of the amniotic fluid after 20 weeks of gestation :

• A. Ultrafiltrate and maternal plasma
• B. Fetal urine
• C. Fetal lung fluid
• D. Fetal skin

Answer 1

The Correct Option is B

In obstetrics, understanding the composition of amniotic fluid is important for recognizing fetal development stages. After 20 weeks of gestation, the primary source of amniotic fluid becomes fetal urine. At this stage, the fetus begins to swallow the amniotic fluid, and in turn, it is excreted again, primarily through urination. This cycle contributes significantly to the volume and composition of the amniotic fluid.

Other contributions to amniotic fluid include:

• Fetal lung fluid: Contributes minimally but aids in developing the lungs.
• Ultrafiltrate of maternal plasma: Plays a role earlier in gestation.
• Fetal skin: Contributes slightly in the early stages before keratinization.

After 20 weeks, amniotic fluid is chiefly maintained by fetal urine, reflecting the maturity of fetal renal function.