Progesterone levels are highest during the luteal and secretory phases of the menstrual cycle.
The Role of Progesterone
During the menstrual cycle, hormones fluctuate, triggering different events. Progesterone is a key player, especially after ovulation.
The Luteal and Secretory Phases
- Dominant Hormone: As referenced, the luteal and secretory phase is dominated by progesterone. This phase occurs after ovulation, when the follicle that released the egg transforms into the corpus luteum.
- Stimulation by LH: Luteinizing hormone (LH) stimulates the corpus luteum to produce progesterone.
- Endometrial Maturation: Progesterone's primary role is to prepare the uterine lining (endometrium) for potential implantation of a fertilized egg. The endometrium thickens and becomes more vascular under the influence of progesterone. This is essential for the early stages of pregnancy.
| Phase | Dominant Hormone | Key Function |
|---|---|---|
| Luteal and Secretory | Progesterone | Prepares endometrium for potential implantation |
Practical Insight
- If fertilization does not occur, the corpus luteum degenerates, and progesterone levels decline, triggering menstruation.
- Measuring progesterone levels can be an indicator of ovulation and can be important in fertility assessments.
