After ovulation, the corpus luteum secretes which hormone to support possible early pregnancy?

• A. Estrogen
• B. Progesterone
• C. LH
• D. FSH

Answer: (B)

After ovulation, the follicle becomes the corpus luteum, and its main job is to secrete progesterone. This progesterone drives the endometrium into a secretory state, making it thick, glandular, and richly vascularized so it can support an implanted embryo. It also helps keep the uterus calm and prevents contractions that could disrupt a potential pregnancy. If fertilization occurs, the developing embryo produces hCG, which rescues the corpus luteum so it can continue producing progesterone until the placenta takes over. If pregnancy does not occur, the corpus luteum regresses, progesterone (and estrogen) fall, and the endometrium is shed as menses. Estrogen is still produced, but its role after ovulation is more about supporting the endometrium's structure rather than providing the primary pregnancy support. LH drives ovulation and then stimulates the corpus luteum; FSH primarily governs follicle growth earlier in the cycle. The hormone most associated with sustaining early pregnancy after ovulation is progesterone.