The Normal Menstrual Cycle & Menopause Flashcards
normal menstrual cycle - overview
*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
taking a menstrual history
- frequency (normally every 24-38 days)
- regularity:
-variation in cycle length (different between the shortest and longest cycle)
-normal variation 7-9 days; most regular ages 26-41 - duration:
-number of bleeding days in a single menstrual period
-no consensus on “normal” - volume:
-subjective; often defined in number of tampons/pads per day
normal menstrual cycle - hypothalamus & pituitary
*hypothalamus secretes GnRH in a pulsatile fashion, leading to FSH/LH secretion from the pituitary gland
normal menstrual cycle - ovary: follicular phase
*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/LH 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
normal menstrual cycle - ovary: luteal phase
*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 FSH, thereby initiating the entire process all over again
Mittelschmerz Pain
*transient ovulatory pain
*follicular swelling / rupture causes peritoneal irritation/tube spasm
*can mimic appendicitis
*“middle hurts”
*can last hours to days
normal menstrual cycle - uterus: proliferative & secretory phases
*estrogen from developing follicles (in follicular phase) stimulates endometrial proliferation during proliferative phase
*after ovulation, progesterone (from corpus luteum) stimulates the maturation of the endometrium to support implantation during the secretory phase
ovarian cycle: follicular phase (simple)
*1st day of menses to ovulation
*follicular development
*late stages are stimulated by FSH
*can fluctuate in length
ovarian cycle: luteal phase (simple)
*from ovulation to first day of menses
*corpus luteum formation from follicular remnants
*stimulated by LH
*lasts a fixed 14 days
uterine cycle: proliferative phase (simple)
*1st day of menses to ovulation
*endometrial development
*stimulated by estrogen
*straight, narrow endometrial glands
uterine cycle: secretory phase (simple)
*ovulation to first day of menses
*endometrial preparation for implantation
*stimulated by progesterone
*tortuous, dilated endometrial glands
if fertilization occurs…
*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
menopause - overview
*cessation of menstrual periods due to the natural decline in ovarian function
*average age is 50-52; can be affected by genetics, smoking
stages of menopause
- perimenopause: irregular menstrual periods
-symptoms can include hot flashes, insomnia, irritability
-can last 4-5 years or longer - menopause: defined as 12 months after last menstrual period
-production of progesterone slows and ovulation ceases - postmenopause: years following menopause
physiology of menopause
- ovarian aging: gradual depletion of ovarian follicles leads to decreased estrogen and progesterone production
- 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
hormones of menopause: elevated FSH & LH, decreased estrogen
symptoms of menopause: hot flashes
*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
symptoms of menopause: depression
*diagnosis of depression is 2.5x more likely during menopausal transition
*association most marked in women with previous history of depression/mood disorder
symptoms of menopause: sleep disturbances
*some due to hot flashes
*increased risk of sleep disturbances without hot flashes
*up to 45% of women
symptoms of menopause: cognitive changes
*forgetfulness
*word finding difficulty
*“brain fog”
symptoms of menopause: genitourinary syndrome of menopause
*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
symptoms of menopause: other symptoms
*joint aches and pain
*breast pain
*menstrual migraines
long-term consequences of low estrogen
*bone loss
*cardiovascular disease
*dementia
*osteoarthritis
*skin changes (collagen content of skin and bones reduced by estrogen deficiency)
*balance
non-estrogen treatment of menopause-related hot flashes
- SSRIs: paroxetine (contraindicated in breast cancer pts taking tamoxifen)
- gabapentin
- herbal treatments: Black Cohosh
- mind-body treatment
non-estrogen treatment of menopause-related vaginal dryness
- ospemifene: selective estrogen receptor modulator (SERM)
- vaginal lubricants and moisturizers
menopausal hormone therapy (MHT) - overview
*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
menopausal hormone therapy (MHT) - contraindications
*history of breast cancer
*coronary heart disease
*previous VTE or stroke
*active liver disease
menopausal hormone therapy (MHT) - BENEFITS
*relief from vasomotor symptoms
*decreased risk of osteoporosis and fractures
*improvement in mood and sleep
*reduced vaginal dryness and urinary symptoms
menopausal hormone therapy (MHT) - RISKS
- cardiovascular risk: increased risk of heart disease and stroke, especially in older women
- breast cancer: slightly increased risk with long-term use, particularly combined estrogen + progesterone
- endometrial cancer: increased risk if estrogen is used alone in women with a uterus
- venous thromboembolism (VTE): risk of blood clots, especially with oral MHT
