Hormonal Contraception Flashcards
How does exogenous estrogen aid in contraception?
- Estrogen increases pulse of GnRH → LH (rather than FSH) → prevents follicle stimulation and steroidogenesis.
- Estrogen and progesterone inhibit FSH / LH release.
How does exogenous progesterone aid in contraception?
Effects of progestin only pills (3)
Which women should use a progestin-only pill?
Important instruction for progestin-only pill
- Progestins decrease freq of GnRH / LH pulses, decreasing ovulation.
- Effects of progestin only pills: decreased tubal motility / secretion, cervix / mucus becomes less permeable to sperm, and endometrium becomes less responsive to implantation.
- Used in women w/ contraindications to estrogen (thromboembolic disease, tobacco use over age 35)
- Good for women who are breast feeding (estrogen inhibits lactation)
- Very important to take at the same time each day.
How do OCPs help PCOS? (3)
- Progestin suppresses GnRH pulse freq → low LH → low androgens
- Estrogen suppresses FSH → decreased follicular development → decreased androgens. Estrogen also increases SHBG → decreased free testosterone
How do OCPs help endometriosis?
- Combined HC → less endometrial build-up than normal (lighter periods). Most pain occurs during menses, so less pain if extended-use is implemented.
- Progestin only HC → endometrial glandular atrophy + fibrosis of ectopic endometrium.
How do OCPs help migraines?
Menstrual migraines may be caused by shift in hormones every month, esp decline in estrogen during late luteal phase. These can be decreased by giving OCPs. Extended-use is best.
How do OCPs help acne?
Estrogen increases SHBG
6 health benefits of HC
- Decreased rates of ovarian cancer due to suppression of ovulation and less follicle stimulation.
- Decreased risk of endometrial cancer due to progestin-mediated suppression of estrogen-induced endometrium proliferation.
- Decreased acne due to increased SHBG
- Decreased anemia due to suppressed menses
- Reduced ovarian cysts
- Reduced fibrocystic breast changes
Adverse effects of HC (6)
- HC has slight increased risk of MI / stroke due to arterial disease and slight increased risk of thromboembolism due to venous disease. Estrogen causes more problems than progestin.
- Acceleration of atherogenesis
- Estrogens increase HDL / lower LDL. Progestins have androgenic activity, which can decrease HDL
- 5% risk of HTN due to activation of renin-angiotensin system. MUST check BP in women on HC
- Thrombosus: Increase in factor VII – X, plus decrease in antithrombin III. Similar to coagulation changes seen in pregnancy
3 contraindications to HC
Tobacco, hx of thromboembolism, or uncontrolled HTN in women >35 y/o
In which pxs should low-dose progestin pills be used? (5)
Pxs w/ progestin sensitivity, such as PMS, depression, bloating, headache, and edema
Disadvantage of combined estrogen / progestin patch
Less consistent levels (peaks are higher and troughs are lower). Do not use in high-risk women.
Adverse effect of estrogen / progestin vaginal ring (NuvaRing)
Increased risk of thrombotic complications compared to OCPs
Advantages / disadvantages of progestin depot injections
- Benefits – decreases menses, cramps, and risk of PID
* Disadvantages – menstrual irregularities, WEIGHT GAIN, and decreased bone density.
Progestin-only emergency contraception
Access
Potential mechanisms (4)
- Levonorgestrel
- Available over the counter for women 17+ y/o. If under 17 need prescription. Also need prescription if >72 hrs after sex.
- Potential mechanisms
- Disrupts normal follicular growth
- Blocks LH surge (inhibits ovulation if taken prior to ovulation, which is good b/c sperm can live in uterus for 5-7 days.)
- Creates deficient luteal phase
- Inhibits tubal transport of sperm / ova
