Its All About the Menstrual Cycle

The menstrual cycle from beginning to end is approximately 21-35 days beginning with the menstruation/period (BR; R.B.G.C., 2018). It is highly variable and depends greatly on the fluctuations of several hormones including estrogen, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and progesterone. The three parts of the menstrual cycle under this hormonal control are the follicular phase, ovulation, and the luteal phase. When there is an imbalance or hormonal dysfunction, women may have abnormal bleeding, trouble getting pregnant, or no menstrual period at all.

Each phase and its correspondence to the menstrual cycle is depicted below. (Normal menstruation 2019)

• Follicular phase: Day 1-13. The increase in FSH and estrogen.

• Ovulation: Day 14 (woman is fertile 5 days prior). Sudden increase LH called the “LH surge”.

• Luteal Phase: Day 15-28. Levels of progesterone will begin to rise. If pregnancy is not achieved, progesterone and estrogen will decrease in preparation for menses.

The average age to start menstruation is around 11-12 and women usually stop having a period around the age of 51. (Normal menstruation, 2019)

An overview of the entire menstrual cycle is as follows: (Your period, 2022)

• Days 1-5: Women will have menstrual bleeding which can vary anywhere from 3 to 8 days.

• Day 6-14: Uterine lining/endometrium prepare for possible pregnancy by thickening, a process driven by estrogen.

• Day 14-25: Ovulation occurs which entails release of a single egg from an ovary. If sperm is present and reaches the egg, this is when fertilization will occur leading to the beginning of pregnancy.

• Day 25- 28: If the egg remains unfertilized, the uterus as well as the begins to prepare to shed and the cycle begins again.

References:

BR;, R. B. G. C. (2018, August 5). The normal menstrual cycle and the control of ovulation. National Center for Biotechnology Information. Retrieved September 25, 2022, from https://pubmed.ncbi.nlm.nih.gov/25905282/

Normal menstruation (monthly period): Menstrual Cycle & Symptoms. Cleveland Clinic. (n.d.). Retrieved September 25, 2022, from https://my.clevelandclinic.org/health/articles/10132-normal-menstruation

Your period. Menstrual Cycle Basics – Your Period. (n.d.). Retrieved September 25, 2022, from https://www.yourperiod.ca/normal-periods/menstrual-cycle-basics/#cycleGeneral