Which phase is part of the uterine cycle?

• A. Proliferative
• B. Ovulation
• C. Luteal
• D. Follicular

Answer: (A)

The uterine cycle refers to the changes in the endometrium driven by ovarian hormones, with two main phases: proliferative and secretory. The proliferative phase is the period when estrogen stimulates the endometrium to regrow and thicken after menstruation, preparing a lining that could support implantation if a pregnancy occurs. This is a true uterine-cycle phase because it describes the endometrium’s growth pattern.

Ovulation is an event in the ovarian cycle—the release of an egg from the ovary—not a phase of the uterine lining itself. The terms luteal and follicular likewise describe ovarian stages: the follicular phase involves follicle development and estrogen production, while the luteal phase follows ovulation with progesterone production by the corpus luteum. While progesterone during the luteal time influences the uterus by promoting secretory changes, that uterine-phase label is called secretory, not luteal. So the proliferative phase is the correct uterine-cycle phase.