General Medicine Obstetrics and Gynecology

Menstrual Cycle PDF

Menstrual Cycle

A.Series of rhythmic reproductive cycle

  • From the onset of menstrual bleeding to the next period
  • Characterized by changes in the ovaries and uterus
  • Influenced by normal hormonal variation mediated by hypothalamus and anterior pituitary gland via feedback mechanis
  • Recurring cyclically beginning at puberty with first menstruation called the  MENARCHE and ceasing at MENOPAUSE
  • Mean cycle length  of 28 days; normal range 25-28 day per cycle

B.Function of the cycle

  • In preparation for the release of egg, fertilization and implantation

Menstrual Cycle

c. Hormonal Control of Menstrual Cycle

Menstrual Cycle

1. Follicle Stimulating Hormone (FSH)
  • Secreted by the anterior pituitary gland during the first half of the menstrual cycle
  • Stimulate the development of graafian follicle
  • Thickens the endometrium

Menstrual Cycle

2.Luteinizing Hormone (LH)
  • Secreted by the pituitary gland
  • Stimulates ovulation and development of corpus luteum
  • Thickens the endometrium
3. Estrogen
  • Secreted primarily by the ovaries, by the adrenal cortex and by the placenta in pregnancy
  • Stimulates thickening of the endometrium causes suppression  of FSH secretion
  • Assist in maturation of  ovarian follicles
  • Responsible for the development of secondary sex characteristics
  • Stimulates uterine contractions
  • Mildly accelerates sodium and water reabsorption by kidney tubules; increase water content of the uterus
  • High estrogen contraction-inhibits secretion of FSH and prolactin but stimulates secretion of LH
  •  Low estrogen concentration after pregnancy, stimulates secretion of prolactin
  • Accelerates protein anabolism
  • Responsible for the fertile cervical mucus; clear, stingy, stretchable, slippery, with fern patterns when dry
4. Progesterone
  • Secreted by corpus luteum and placenta during pregnancy
  • Inhibits secretion of LH
  • Has thermogenic effect (increases basal body temperature)
  • Relaxes smooth muscles
  • Responsible for infertile mucus, opaque, sticky, thick, non-stretchable, non-fern pattern when dry
  • Maintain thickness of endometrium
  • Allows pregnancy to be maintained
5. Prostaglandin
  • Fatty acids categorized a hormone
  • Produced by many organs of the body, including the endometrium
  • Affects menstrual cycle
  • Influences the onset and maintenance of labor

Phases of Menstrual Cycle

  Menstrual Cycle

  1. Menstrual Phase (Day 1-5)
    1. Corpus luteum degenerates
    2. There is cessation of progesterone and estrogen produced by corpus luteum and blood level stops
    3. Endometrium degenerates and menstruation occurs
    4. Drop in blood levels of estrogen and progesterone stimulate production of FSH and new cycle begins
  2. Proliferative Phase (Day 6-14)
    • Follicle-stimulating hormone (FSH) released by the anterior pituitary stimulates the development
    • As graafian follicle develops, it produces increasing amounts of follicular fluid containing a hormone called estrogen
    • Estrogen stimulates thickening of the endometrium
    • As estrogen increasing in the bloodstream, it suppresses secretion of FSH and favors secretion of the luteinizing hormone (LH)
    •  LH stimulates ovulation and initiates development of corpus luteum
      Menstrual Cycle
  3. Secretory Phase (Day 15-21)
    • Follows ovulation, which is the release of mature ovum from the graafian follicle
    • Cavity of the graafian follicle is replaced by the corpus luteum (secretes progesterone and some estrogen)
    • Progesterone acts upon the endometrium to bring about secretory changes that prepare it for pregnancy. It also
    • maintains the endometrium during the early phase of pregnancy, should a fertilized ovum be implanted
  4. Pre- Menstrual (Day 22-26)
    1. If fertilization does not occur the corpus luteum in the ovary begins to regress
    2. Production of progesterone and estrogen decreases
    3. Endometrium of uterus begins to degenerate and sloughs off
    4. Endometrium becomes thicker and vascular ready for implantation

Menstrual Disorders

Dysmenorrhea – pain with menses

  1. Primary – begins 1-3 months after menarche in conjunction with ovulatory cycles
  2. Secondary – suspected when pain is concentrated on a specific area or only on one side when its onset occurs after age 20
  • Due to unknown factors
  • Thought to be intrinsic to uterus; excessive production of prostaglandins
  •  Sedentary occupation
  •  Poor posture
  •  Poor personal hygiene
  •  Constitutional illness such as anemia
  •  Daughter of women who have suffer or have suffered from dysmenorrhea are frequently dysmerrheic
Sign and Symptoms:
  • Cramps in the lower abdomen and occasionally into the groin, thigh, and vulva
  • Tension
  • Nausea and vomiting
  • Malaise
  • Chills and shivering
  • Diarrhea
  • Pallor
  • Hot and cold sensation
  • Fainting in some cases
Treatment and Management

Explanation or normal and anatomy and physiology of menstruation-serves to eradicate misconception and lessen fear and anxiety which may be associated with her periods

Nursing Management
  • Instruction  in menstrual hygiene-so that her period does not seem distasteful and restricting, encourage frequent bathing
  • Encourage to get more good posture and exercise particularly aerobics (cycling, jogging, walking, and waist bending before the onset of the period)
  • Avoidance over fatigue and overexertion during the period
  • Apply heat (e.g. warm baths, putting a hot water bottle, or heating pads on the abdomen)
  • Focuses on education and psychosocial needs of the patient
  • Encourages to drink plenty of fluids, but avoid alcohol
  • Divert attention
  • Encourage rest and sleep
  • Apply relaxation technique; massage
  • Avoid aspirin or prostaglandin inhibitor such as ibuprofen, mefenamic acid-medication are to be taken with water, milk may be used if the medication causes an upset in the stomach
  • Usually eliminated by oral contraception which blocks ovulation