Besides progesterone, which hormone is also produced by the corpus luteum to support the endometrium early in pregnancy?

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

Answer: (B)

The question tests what hormones the corpus luteum makes to support the endometrium after ovulation. After ovulation, the corpus luteum predominantly secretes progesterone to keep the endometrium thick and secretory, ready for implantation. It also produces estrogen (estradiol) in the luteal phase and early pregnancy. Estrogen from the corpus luteum helps promote endometrial proliferation, gland development, and vascular support, working together with progesterone to create a receptive, maintained lining for implantation.

In early pregnancy, human chorionic gonadotropin from the developing embryo keeps the corpus luteum functioning, so both progesterone and estrogen continue to be produced until the placenta takes over later.

The other hormones listed are not produced by the corpus luteum: LH and FSH are pituitary gonadotropins that stimulate ovulation and follicle development, not the maintenance of the endometrium after ovulation.