Menstruation and Cycle Factors

Menstruation

• Menstruation is the episodic uterine bleeding in response to cyclic hormonal changes.
• It involves a complex interplay of events within the endometrium, hypothalamus, pituitary glands, and ovaries.
• The purpose of the menstrual cycle is twofold: to bring an ovum to maturity and to renew the uterine tissue bed.

Factors Affecting Menstrual Cycle Regularity

• Age
• Physical and emotional status
• Environmental influences

Key Terms

• Graafian follicle: An ovarian oocyte activated by FSH, developing into an ovum with a surrounding membrane and fluid.
• Ovulation: The release of a mature egg from the ovary, allowing fertilization. Ovulation is approximately 14 days from the end of the cycle, not necessarily day 14 of the cycle.
• Corpus luteum: A follicle left behind after ovulation, producing lutein, a yellow fluid rich in progesterone (yellow body).
• Progesterone: A hormone that is thermogenic (involved in heat regulation).
• Corpus albicans: A white fibrous tissue replacing the corpus luteum as it regresses.

Menarche and Puberty

• Puberty: The transitional stage between childhood and sexual maturity.
• Menarche: The first menstruation.
• Initially, menstrual cycles are irregular.
• Menstrual periods tend to become regular after a year or more.

Menstrual Cycle Length and Flow

• Average menstrual cycle length is 28 days.
• Average menstrual flow duration is 4-6 days.
• Counting the cycle: Start from the beginning of one flow to the next.

Characteristics of Normal Menstrual Cycles

• Menarche: Average age of onset is 12-13 years, with a range of 9-17 years.
• Interval between cycles: Average 28 days, with 23-35 days being typical.
• Duration of menstrual flow: Average 5 days, with a range of 3-6 days.
• Amount of menstrual flow: Average 50 mL (range 20-80 mL).
• Color of menstrual flow: Dark red, a combination of blood, mucus, and endometrial cells.

Physiology of the Menstrual Cycle

• Hypothalamus: Releases GnRH, initiating the menstrual cycle.
• Pituitary gland: Under the influence of GnRH, produces LH and FSH.
• Ovaries: FSH stimulates ovarian production of estrogen. LH triggers ovulation and corpus luteum development.
• Uterus: Prepares the uterine lining for potential implantation.

Ovulation Timing

• If your average menstrual cycle is 28 days long, you will ovulate around day 14.
• If your cycle is 30 days long, you will ovulate around day 16.

Menstrual Flow Composition

• Blood from ruptured capillaries
• Mucin from glands
• Fragments of endometrial tissue
• Microscopic pieces, atrophied endometrial tissue, and unfertilized ovum
• The first day of the flow marks the beginning of a new cycle.

Blood and Iron Loss

• Average blood loss is 20-80 mL.
• Average iron loss is 11 mg.

Ovarian and Uterine Cycles

• The ovarian and uterine cycles occur simultaneously.
• They are divided into phases (follicular, ovulation, luteal, and menstrual).

Ovarian Cycle

• Follicular phase: development of follicles
• Ovulation phase: release of the egg
• Luteal phase: formation of corpus luteum
• Menstrual phase: shedding of the uterine lining

Corpus Luteum

• If fertilization occurs, the corpus luteum remains for the major portion of pregnancy (16–20 weeks).
• If fertilization doesn't occur, the corpus luteum regresses and is replaced by corpus albicans.

Corpus Albicans

• If conception does not occur, the corpus luteum regresses and is gradually replaced by white fibrous tissue.

Menstrual Phase

• If conception does not occur, the unfertilized ovum deteriorates within 4-5 days.
• The endometrial lining sheds, marking the beginning of a new cycle.

Endometrial/Uterine Cycle

• Proliferative phase
• Secretory phase
• Ischemic phase
• Menstrual phase

Proliferative Phase

• Also known as estrogenic, follicular, or postmenstrual phase.
• Characterized by the thickening of the endometrium.
• Thickening occurs due to estrogen.

Secretory Phase

• Progestational, luteal, or premenstrual phase.
• Extends from the time of ovulation.
• Marked by the production of progesterone and endometrial thickening.

Ischemic Phase

• Happens 7-10 days after ovulation.
• Due to regression of corpus luteum.
• Marked by a drop in hormones.
• Progressive decrease in blood supply to the endometrium resulting in necrosis and impending menstruation
• The functional endometrial layer separates from the basal layer.

Menstrual Phase

• Day 1 of the menstrual cycle, starting with the shedding of the functional endometrial layer.
• Initiated by periodic vasoconstriction in the upper layers.
• It marks the start of a new cycle.

Cervical Changes

• Cervical mucus alters throughout the cycle.
• Helpful for fertility.
• Thin, stretchy, and copious mucus is ideal for sperm.
• Cervical mucus plays a critical role in fertility
• During ovulation, the cervical mucus becomes watery, stretchy, and plentiful - this aids sperm survival and penetration.

Testing for Ovulation

• Fern test: Cervical mucus forms fern patterns on a glass slide just before ovulation.
• Spinnbarkeit test: Stretchability of cervical mucus indicates ovulation.

Health During Menstruation

• Exercise: Moderate exercise is recommended.
• Sexual Relations: Not contraindicated but condoms are recommended.
• Daily Activities (ADL): Daily activities are not limited.
• Rest: Additional rest may benefit those with dysmenorrhea.
• Nutrition: There are no dietary restrictions. Iron supplementation may help replace lost iron.

Menstrual Disorders

• Dysmenorrhea: Painful menstruation. Can be primary (from uterine contractions) or secondary (from pelvic issues).
• Premenstrual syndrome (PMS): A complex condition with cyclic symptoms (fluctuations in mood, etc).
• Premenstrual dysphoric disorder (PMDD): More severe form of PMS, involving intense irritability, depression, or anxiety prior to menstruation.
• Abnormal uterine bleeding: Any form of bleeding that is irregular in amount, duration, or timing. (Anovulation, Pregnancy, Infections, etc.)
• Oligomenorrhea/hypomenorrhea: Decreased menstruation.
• Polymenorrhea: Frequent menstruation.
• Menorrhagia: Abnormally heavy menstrual bleeding.
• Metrorrhagia: Bleeding between menstrual periods.

Menopause

• Menopause: Cessation of menstrual cycles.
• Postmenopausal period: Time following menopause.
• Perimenopausal period: Period during which menopausal changes occur.

Health Teaching During Menopause

• Educate women about the changes and their impact on daily life.
• Address hormone replacement therapy options.

Explore the complexities of menstruation and the factors affecting the regularity of the menstrual cycle. This quiz covers key terms and hormonal interplays involved in ovulation and uterine changes. Understand the significance of age, physical health, and environmental influences on menstrual patterns.