female contraception Flashcards
Contraception statistics in the U.S.
Birth control pills - 17.3%
Tubal ligation sterilization - 16.7%
Male condom - 10%
Vasectomy sterilization - 6.1%
Common progression: condom –> birth control pills –> sterilization
1/2 of unintended pregnancies are due to misuse of contraceptives
Interference with normal menstrual cycle
- Remember: during luteal phase, GnRH is inhibited by hormones secreted by the corpus luteum: P+E
- oral contraceptives mimic this scenario
- high estrogen (from follicle) is not obtained –> no positive feedback
- no ovulation
- no fertilization
- Also, cervical mucus is antagonistic to sperm transport
- Also, endometriu is not sufficient to support implantation
Advantage: reversible – fertile within 3 months
Progestins
Administered for 3 weeks
One week absence - withdrawal bleeding
- endometrium (stratum functionalis) sloughs off
- generally lighter than normal menstruation flow
Minipill
- low dose progestin for 28 days
- spotting
- safe during breastfeeding
- higher failure rate - increased risk of ectopic pregnancy
Progestins and estrogens
- estrogen also inhibits GnRH and FSH/LH release
- contributes to maintenance of endometrium during 3 weeks hormonal treatment (decreases breakthrough bleeding)
Combined oral contraception (“the pill”)
- original concentrations were higher than is currently used
- synthetic hormones are used: (estrogen = ethinyl estradiol or mestranol) (progestins: 8 types)
- 1st 10 mg P and 150 ug E
- Now <2 mg P and 35 ug E
oral combination pill
different phases
0.3% failure rate with perfect use
Monophasic pills
-same hormone concentration for 3 weeks
Biphasic and triphasic also exist
Some formulations have a reduced “no hormone” time of 4 days rather than 7
Extended cycle pills
- fixed dose for up to 84 days + 7 inactive days
- only have a menstrual flow once in 3 months
Continuous cycle pills
-no menstrual flow
side effects
Mild: nausea, bloating, fluid retention, slight weight gain, mood changes, headaches, breast tenderness, increased blood sugar levels, changes in libido, minor blood clotting, increased BP, lactation suppression
Serious
- no increased risk of breasst cancer
- increased risk of cervical cancer with extended use (>5 yrs) - temporary
- increased risk of benign and cancerous liver tumors
Risk of death from COC > pregnancy > childbirth
cardiovascular effects
Smoking
Usually a function of predispositions to CV disease
- hypertension
- increased risk of blood clots
Less of a pproblem with newer, lower dose formulas
Side benefits
lower risk of ovarian cancer lower risk of endometrial cancer lower risk of colorectal cancer lower risk of pelvic inflammatory disease (infection of repre organs) helps with acne helps with craps/pain and reduces flow helps with endometriosis helps with PMS helps with anemia
Non-health pros and cons
convenient - you can have sex low failure if used right accessible, but not cheap doesn't protects against STDs Side effects: mild vs serious
Oral and injectable progestin
Oral: metabolized by liver after absorption; decreases hormone concentration
Injectible progestin (IM- deltoid, gluteal)
- shot every 3 months
- bone loss side effect - contraindicted in adolescent and women at risk for osteoporosis
- takes longer to reverse
Implant and Patches
Subdermal progestin implants
- inner upper forearm location of flexible plastic rod
- hormone released over 3 yrs
- original 6-tubes implant Norplant no longer used bc of tissue damage
Transdermal E+P
- worn on skin
- applied once a week for 3 weeks
Vaginal ring and morning after pill
Ring
- plastic ring with E+P
- vaginal absorption for 3 weeks
Pill
- emergency contraception
- P given post coital ASAP
- inhibits ovulation til sperm aren’t viable
- only effective if ovulation hasn’t occured and doesn’t prevent fertilization or induce abortion
IUD
T-shaped and placed in uterus
- Flexible plastic with progestin (5 years)
- Copper wire wrapping (10 years)
- String extends down through cervical os
Prevents sperm transport to prevent fertilization
Causes inflammation
-White blood cells in uterus destroy sperm
If copper IUD: spermicidal
With progestin: cervical mucus effect to decrease sperm transport
Side effects of IUD
Painful insertion with cramping
Higher menstrual flow w/copper
Lighter menstrual flow w/progestin
Possible amenorrhea after several years of use
If a pregnancy does occur - removal with risk of miscarriage
Surgical sterilization
Tubal ligation:
- Oviducts are treated to prevent passage of sperm and/or egg
- Removed, cauterized, plugged with chemicals/silicone, tied
- Insertion of metal coils that induce scar tissue formation (no incision)
Minilaparotomy
- Small abdominal incision under local anesthesia
- Postpartum – incision at naval due to higher location of tubes during pregnancy
Laparoscopy with attachments
-Optical tube used to locate oviducts
Increases risk of ectopic pregnancies (w/partial blockage)
Low failure rate (0.5%)
