What is the role of progesterone during the luteal phase?
Apr 07, 2022
Source: Cainiu Health
Dr. Chen Zhe
Introduction
The menstrual cycle is divided into the ovarian phase, ovulation phase, and luteal phase. The luteal phase spans from the day after ovulation to the day before menstruation begins—i.e., days 15 to 28 of the menstrual cycle. After the oocyte and follicular fluid are expelled, intracavitary pressure within the follicle decreases, causing the follicular wall to collapse. Granulosa cells then protrude into the cavity, forming numerous folds; concurrently, cells from the follicle, connective tissue, blood vessels, and other structures invade the follicle.
All women experience the luteal phase, during which progesterone levels rise—this phase occurs just before menstruation or during this period. At this time, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels drop sharply. The luteal phase begins immediately after ovulation, when the ruptured follicle transforms into the corpus luteum. What is the role of progesterone during the luteal phase?
What Is the Role of Progesterone During the Luteal Phase?
The menstrual cycle is divided into three phases: the follicular phase, the ovulatory phase, and the luteal phase. The luteal phase spans from the day after ovulation until the day before menstruation begins—typically days 15 to 28 of the menstrual cycle. After the oocyte and follicular fluid are released, intrafollicular pressure decreases, causing the follicular wall to collapse. Granulosa cells protrude into the follicular cavity, forming numerous folds, while connective tissue, blood vessels, and other cells also invade the granulosa cell layer. This stage constitutes the luteal phase.
Progesterone levels fluctuate throughout the menstrual cycle: they remain low during the follicular phase, rise slightly during ovulation, and increase markedly upon entering the luteal phase as the ovary undergoes structural changes and forms the corpus luteum. Progesterone then surges rapidly to its peak within the normal physiological range. The adequacy of progesterone during pregnancy critically depends on corpus luteum function.
Slightly elevated progesterone levels generally do not impair health and suggest that luteal function remains largely intact. Adequate rest is recommended. It is advisable to monitor whether menstruation remains regular, practice appropriate timing of sexual intercourse, and verify whether the menstrual cycle falls within the normal range. In the absence of specific luteal-phase dysfunction, natural conception is typically unaffected—there is no need for undue concern.
