Step 1: hCG Function.
Trophoblastic cells secrete hCG post-fertilization. Its primary role is sustaining the corpus luteum during the first trimester, ensuring continued progesterone production to support the endometrium and pregnancy.
Step 2: hCG Level Dynamics.
Following conception, hCG levels exhibit rapid growth, doubling every 48–72 hours. They persist in their ascent through early pregnancy. hCG levels attain their zenith between 8–12 weeks of gestation.
Subsequently, levels decrease and stabilize at a lower concentration for the remainder of the pregnancy.
Step 3: Option Evaluation.
- (A) 30–41 weeks: Near term; hCG is stable but below peak.
- (B) 8–12 weeks: Correct. This period represents the established peak for hCG.
- (C) 13–16 weeks: hCG levels begin to decline at this stage.
- (D) 17–29 weeks: Levels are stable, not at peak.
Step 4: Determination.
Consequently, hCG reaches its peak between 8–12 weeks of pregnancy, followed by a decline and stabilization.