The Normal Menstrual Cycle & Menopause

Question 1

normal menstrual cycle - overview

Answer 1

*menstrual cycle: regular cyclic changes periodically preparing the female reproductive system for fertilization and pregnancy; occurs in phases, based on events taking place in ovaries & uterus
*lasts 28 days (average 24-35)
*day one of the menstrual cycle = the day the period STARTS

Question 2

taking a menstrual history

Answer 2

1. frequency (normally every 24-38 days)
2. regularity:
   -variation in cycle length (different between the shortest and longest cycle)
   -normal variation 7-9 days; most regular ages 26-41
3. duration:
   -number of bleeding days in a single menstrual period
   -no consensus on “normal”
4. volume:
   -subjective; often defined in number of tampons/pads per day

Question 3

normal menstrual cycle - hypothalamus & pituitary

Answer 3

*hypothalamus secretes GnRH in a pulsatile fashion, leading to FSH/LH secretion from the pituitary gland

Question 4

normal menstrual cycle - ovary: follicular phase

Answer 4

*FSH from anterior pituitary stimulates growth of follicles:
-“follicle recruitment”
-follicular growth is fastest during the second week of follicular phase
*as the follicles grow, they secrete estrogen
*one follicle grows larger than the rest - this is the dominant follicle; dominant follicle suppresses growth of the other follicles, so just one ovulates
*POSITIVE FEEDBACK: estrogen secretion by the growing follicles stimulates increased FSH/LG secretion by the pituitary, eventually triggering the LH surge which causes the dominant follicle to ovulate (release its egg), thus marking the end of the follicular phase

Question 5

normal menstrual cycle - ovary: luteal phase

Answer 5

*begins when the LH surge triggers ovulation around day 14 of cycle
*ALWAYS LASTS 14 DAYS, so ovulation + 14 days, period starts
*ruptured follicle develops into corpus luteum (“yellow body”)
*corpus luteum now secretes estrogen and progesterone
*without hCG from pregnancy, the corpus luteum dies; the dropping progesterone and estrogen levels cause a rise in PSH, thereby initiating the entire process all over again

Question 6

Mittelschmerz Pain

Answer 6

*transient ovulatory pain
*follicular swelling / rupture causes peritoneal irritation/tube spasm
*can mimic appendicitis
*“middle hurts”
*can last hours to days

Question 7

normal menstrual cycle - uterus: proliferative & secretory phases

Answer 7

*estrogen from developing follicles (in follicular phase) stimulates endometrial proliferation during proliferative phase
*after ovulation, progesterone stimulates the maturation of the endometrium to support implantation during the proliferative phase

Question 8

ovarian cycle: follicular phase (simple)

Answer 8

*1st day of menses to ovulation
*follicular development
*late stages are stimulated by FSH
*can fluctuate in length

Question 9

ovarian cycle: luteal phase (simple)

Answer 9

*ovulation to first day of menses
*corpus luteum formation from follicular remnants
*stimulated by LH
*lasts a fixed 14 days

Question 10

uterine cycle: proliferative phase (simple)

Answer 10

*1st day of menses to ovulation
*endometrial development
*stimulated by estrogen
*straight, narrow endometrial glands

Question 11

uterine cycle: secretory phase (simple)

Answer 11

*ovulation to first day of menses
*endometrial preparation for implantation
*stimulated by progesterone
*tortuous, dilated endometrial glands

Question 12

if fertilization occurs…

Answer 12

*the developing syncytiotrophoblasts of placenta secrete human chorionic gonadotropin (hCG)
*hCG maintains the corpus luteum, which continues to secrete progesterone until around 8-10 weeks of pregnancy
*after 8-10 weeks of pregnancy, the placenta takes over the estrogen and progesterone production and the corpus luteum degenerates

Question 13

menopause - overview

Answer 13

*cessation of menstrual periods due to the natural decline in ovarian function
*average age is 50-52; can be affected by genetics, smoking

Question 14

stages of menopause

Answer 14

1. perimenopause: irregular menstrual periods
   -symptoms can include hot flashes, insomnia, irritability
   -can last 4-5 years or longer
2. menopause: defined as 12 months after last menstrual period
   -production of progesterone slows and ovulation ceases
3. postmenopause: years following menopause

Question 15

physiology of menopause

Answer 15

1. ovarian aging: gradual depletion of ovarian follicles leads to decreased estrogen and progesterone production
2. hormonal changes:
   -estrogen: decreases significantly
   -progesterone: levels drop as ovulation ceases
   -FSH: increases due to loss of negative feedback from estrogen
   -LH: often elevated as well, esp. post-menopause

Question 16

symptoms of menopause: hot flashes

Answer 16

*aka “vasomotor symptoms” or “hot flushes”
*occur in up to 80% of women, but only 20-30% seek treatment
*some women get these in late reproductive years, some during perimenopause
*begin as sensation of heat in chest / face which becomes generalized
*lasts 2-4 minutes
*very common at night
*can severely impact function in life / work, concentration, mood

Question 17

symptoms of menopause: depression

Answer 17

*diagnosis of depression is 2.5x more likely during menopausal transition
*association most marked in women with previous history of depression/mood disorder

Question 18

symptoms of menopause: sleep disturbances

Answer 18

*some due to hot flashes
*increased risk of sleep disturbances without hot flashes
*up to 45% of women

Question 19

symptoms of menopause: cognitive changes

Answer 19

*forgetfulness
*word finding difficulty
*“brain fog”

Question 20

symptoms of menopause: genitourinary syndrome of menopause

Answer 20

*collection of symptoms/signs caused by hypoestrogenic changes to labia, clitoris, vagina, urethra, bladder
*usually develops later than vasomotor symptoms
*estrogen deficiency causes lower blood flow to genital area = decreased lubrication
*increase in sexual dysfunction
*incontinence

Question 21

symptoms of menopause: other symptoms

Answer 21

*joint aches and pain
*breast pain
*menstrual migraines

Question 22

long-term consequences of low estrogen

Answer 22

*bone lone
*cardiovascular disease
*dementia
*osteoarthritis
*skin changes (collagen content of skin and bones reduced by estrogen deficiency)
*balance

Question 23

non-estrogen treatment of menopause-related hot flashes

Answer 23

1. SSRIs: paroxetine (contraindicated in breast cancer pts taking tamoxifen)
2. gabapentin
3. herbal treatments: Black Cohosh
4. mind-body treatment

Question 24

non-estrogen treatment of menopause-related vaginal dryness

Answer 24

1. ospemifene: selective estrogen receptor modulator (SERM)
2. vaginal lubricants and moisturizers

Question 25

menopausal hormone therapy (MHT) - overview

Answer 25

*estrogen + progesterone therapy for women with intact uterus to prevent endometrial hyperplasia from unopposed estrogen
*estrogen only for post-hysterectomy patients
*forms of estrogen: oral, transdermal, vaginal creams or rings
*forms of progesterone: oral, IUD, IM

Question 26

menopausal hormone therapy (MHT) - contraindications

Answer 26

*history of breast cancer
*coronary heart disease
*previous VTE or stroke
*active liver disease

Question 27

menopausal hormone therapy (MHT) - BENEFITS

Answer 27

*relief from vasomotor symptoms
*decreased risk of osteoporosis and fractures
*improvement in mood and sleep
*reduced vaginal dryness and urinary symptoms

Question 28

menopausal hormone therapy (MHT) - RISKS

Answer 28

1. cardiovascular risk: increased risk of heart disease and stroke, especially in older women
2. breast cancer: slightly increased risk with long-term use, particularly combined estrogen + progesterone
3. endometrial cancer: increased risk if estrogen is used alone in women with a uterus
4. venous thromboembolism (VTE): risk of blood clots, especially with oral MHT