Contraception and hormone replacement therapy Flashcards
(22 cards)
What functions does the endocrine system regulate?
Growth, metabolism
Immune response
Salt retention
Bone density
Reproductive function
What diseases result from endocrine dysfunction?
Growth retardation
Infertility
Hypothyroidism
Grave’s disease
Diabetes
Which hormones regulate ovulation?
- GnRH (hypothalamus) → FSH & LH (anterior pituitary) → stimulates ovarian follicle development
What role do estrogen and progesterone play?
- Released by follicles and corpus luteum → regulate reproductive tissues & inhibit further gonadotrophin release
What happens early in the cycle?
- FSH levels rise → follicle development → follicle releases estrogen → endometrial proliferation
What triggers ovulation?
- High estrogen levels → LH surge → follicle rupture → ovum release
- What happens post-ovulation?
- Follicle forms corpus luteum → releases progesterone → prepares endometrium for implantation
What happens without implantation?
Corpus luteum ceases progesterone production → menstruation occurs
What hormones do combined contraceptive pills contain?
- Synthetic estrogen (ethinylestradiol) & progestogen (varied derivatives)
How do contraceptive pills prevent pregnancy?
- Activate negative feedback loops → inhibit FSH & LH secretion → prevent ovulation
What does withdrawal of progesterone do?
Mimics normal cycle → stimulates menstruation
How does the mini-pill work?
- Relies only on progestogen → prevents ovulation → alters cervical mucus & endometrial receptivity
Why might some patients prefer it?
Fewer oestrogen-related side effects
- How do selective estrogen receptor modulators (SERMs) work?
- Act as estrogen agonists or antagonists depending on tissue type
- Examples of pro-fertility drugs:
- Clomiphene → prevents estrogen negative feedback → promotes ovulation
- Tamoxifen → developed for fertility, now used in ER-positive breast cancer
What symptoms does HRT help manage?
Hot flushes
Vaginal dryness
Osteoporosis (restores estrogen function post-menopause)
How does estrogen regulate non-reproductive tissues?
Bone density
HDL/LDL balance
Vasomotor effects
Coagulation
Bowel motility
What did the 2003 study suggest about HRT? - The Million Women Study
Increased risk of hormone-sensitive cancers & stroke
Why was the study controversial?
- Prospective cohort design, no prior exposure accounted for
- Later meta-analyses found smaller risk estimates
- Impact on clinical practice:
- Doctors lost confidence in HRT prescribing → generational gap in knowledge
How should HRT risks be communicated?
- Use absolute risk rather than relative comparisons for informed decision-making
What factors should patients consider?
Severity of menopausal symptoms vs. potential cancer risks
