The menstrual or ovarian cycle occurs approximately once every 28–29 days during the reproductive life of females, from menarche (puberty) to menopause, except during pregnancy. The cycle of events starting from one menstrual period until the next one is called the menstrual cycle, during which cyclic changes occur in the endometrium every month. Cyclic menstruation is an indicator of a normal reproductive phase.
Phases of the Menstrual Cycle
The menstrual cycle comprises the following phases:
- Menstrual Phase
- Follicular or Proliferative Phase
- Ovulatory Phase
- Luteal or Secretory Phase
Menstrual Phase
The cycle begins with the menstrual phase, during which menstrual flow occurs and lasts for 3-5 days. Menstrual flow is caused by the breakdown of the endometrial lining of the uterus and its blood vessels as a result of a decline in progesterone and estrogen levels. Menstruation occurs only if the released ovum is not fertilized. Absence of menstruation may indicate pregnancy but could also be due to stress, hormonal disorders, or anemia.
Follicular or Proliferative Phase
The follicular phase extends from the 5th day of the cycle until ovulation. During this phase, the primary follicle in the ovary grows to become a fully mature Graafian follicle. At the same time, the endometrium regenerates through proliferation. These changes are induced by the secretion of gonadotropins like FSH and LH, which increase gradually during the follicular phase, stimulating follicular development and the secretion of estrogen by the follicle cells.
Ovulatory Phase
Both LH and FSH peak in the middle of the cycle (about the 14th day). Maximum LH secretion during the mid-cycle, known as the LH surge, causes the rupture of the Graafian follicle and the release of the ovum (secondary oocyte) from the ovary into the peritoneal cavity, a process called ovulation.
Luteal or Secretory Phase
During the luteal phase, the remaining part of the Graafian follicle transforms into a temporary endocrine gland called the corpus luteum, which secretes large amounts of progesterone essential for maintaining the endometrium. If fertilization occurs, it prepares the fertilized ovum for implantation. The uterine wall secretes nutritious fluid for the fetus; hence, this phase is also called the secretory phase. During pregnancy, all menstrual cycle events stop, and there is no menstruation. In the absence of fertilization, the corpus luteum degenerates completely, leaving a scar tissue called corpus albicans. This degeneration initiates the disintegration of the endometrium, leading to menstruation and marking the next cycle.
Polycystic Ovary Syndrome (PCOS)
PCOS is a complex endocrine system disorder affecting women in their reproductive years. Polycystic means “many cysts,” referring to the many partially formed follicles on the ovaries, each containing an egg. These do not grow to maturity or produce eggs that can be fertilized. Women with PCOS may experience irregular menstrual cycles, increased androgen levels, excessive facial or body hair growth (hirsutism), acne, obesity, reduced fertility, and an increased risk of diabetes. Treatment for PCOS includes a healthy lifestyle, weight loss, and targeted hormone therapy.
Menstrual Disorders
- Amenorrhoea: absence of menstruation. If menarche does not appear by age 18, it is called primary amenorrhoea. Secondary amenorrhea is the absence of menstruation for more than three consecutive months.
- Polymenorrhoea: a menstrual cycle shorter than 21 days, which may be due to hyperactivity of the anterior pituitary gland, psychological disturbances, malnutrition, or chronic pelvic inflammation from STDs like chlamydia or gonorrhea.
- Dysmenorrhoea: pain associated with menstruation, the most commonly reported menstrual disorder. Primary dysmenorrhoea is pain or cramps during the menstrual period caused by prostaglandin secretions in the uterus. Secondary dysmenorrhoea is caused by reproductive system disorders like endometriosis or uterine fibroids.
- Menorrhagia: heavy and prolonged menstrual periods disrupting normal activities, potentially caused by hormonal imbalance, ovarian dysfunction, uterine fibroids, or cancers of the ovary, uterus, or cervix.
- Oligomenorrhoea is an infrequent menstrual period that occurs in women of childbearing age. This condition may indicate a regular absence of menstruation for more than 35 days.
Menstrual Hygiene
Menstrual hygiene is vital for the health, well-being, dignity, empowerment, and productivity of women. Poor menstrual hygiene can lead to increased stress levels, fear, and embarrassment, keeping girls inactive during menstruation and leading to absenteeism from school.
- Hygiene Practices: Using clean and safe absorbable materials such as sanitary napkins, pads, tampons, and menstrual cups. Changing sanitary materials every 4–5 hours as needed provides comfort, cleanliness, and protection from infections. Used sanitary napkins should be wrapped in paper and disposed of properly, not thrown in open areas or flushed down the toilet.
- Disposal: Incinerators are an eco-friendly way to dispose of menstrual waste. Measures are being taken to install incinerators and napkin vending machines in schools, colleges, and public facilities.
Menopause
Menopause is the phase in a woman’s life when ovulation and menstruation stop, typically occurring between the ages of 45 and 50. It signifies the permanent cessation of the primary functions of the ovaries. Symptoms of menopause can include hot flashes, night sweats, mood swings, and vaginal dryness. Hormone replacement therapy (HRT) and lifestyle changes can help manage these symptoms. Regular check-ups and a healthy lifestyle are important to maintain overall health during this transition.