Contraception

Basics

Description

  • Prevention of conception or pregnancy. Ideal contraceptive is 100% effective, has no side effects, is easily reversed, and is readily used by adolescents.
  • Efficacy issues:
    • In practice, contraceptive efficacy is based on two core concepts:
      • Adherence or ability to adequately “do” the method
      • Continuation or length of time over which patient uses method
    • Adherence and continuation improved by superior effectiveness of long-acting reversible contraceptives (LARCs), such as intrauterine devices (IUDs) or subdermal implants. LARCs have failure rates of <1% and approximately 80% continuation rates.
    • The most effective methods should be offered as 1st-line contraceptive options for sexually active persons of all ages.
  • Methods of contraception:
    • LARCs:
      • Etonogestrel implant
        • Single-rod subdermal implant containing 68 mg of progestin etonogestrel. Implant provides contraception for 3 years.
        • Benefits: easy to insert and remove device, insertion site easy to access (nondominant upper arm)
        • Can be placed in not yet sexually active patients considering future sexual activity or for heavy or painful menses
      • Levonorgestrel-releasing IUDs
        • T-shaped polyethylene IUDs containing progestin hormones
        • Ovulation may be suppressed in some women. However, not main mechanism of action. Between 45% and 75% of women ovulate on the 52-mg device, and almost all women ovulate on the lower dose levonorgestrel IUDs.
        • Ovulation on lower dose levonorgestrel IUDs may result in less amenorrhea and more regular menses which can be a desired effect for some women.
        • Mirena®, Liletta® contain 52 mg of levonorgestrel and a release rate of 20 mcg/24 h. Mirena is approved by the U.S. Food and Drug Administration (FDA) for use for 5 years but is effective up to 7 years. Liletta is approved for 4 years, may be similar to Mirena; significantly reduces menstrual bleeding and dysmenorrhea
        • Skylar® IUD is minimally smaller, 28 mm × 30 mm, contains 13.5 mg levonorgestrel, releasing 5 to 14 mcg/24 h, with decline to 5 mcg/24 h after 3 years.
        • Phase II and III trials are being conducted with 8, 12, 16 mcg/24 h products.
      • Copper T380 IUD
        • Contraceptive effect related to in utero oxidation with release of copper ions
        • FDA-approved for use up to 10 years but may be effective for up to 12 years
        • May also be placed as very effective emergency contraceptive and then retained for ongoing pregnancy prevention
    • Moderate-duration contraceptives:
      • Depot-medroxyprogesterone acetate (DMPA or Depo-Provera®)
        • IM injection administered every 13 weeks. Failure rates in real-world settings estimated as low as 6%, likely much higher for adolescents
        • 1-year continuation: 56% for users of all ages, likely lower for adolescents
        • Effective up to 14 weeks, so patients within the dosing window do not need additional pregnancy testing before readministration
    • Short-acting estrogen-progestin contraceptives:
      • General issues:
        • Typically use both estrogen (to minimize breakthrough bleeding) and progestin (to block ovulation) in variety of delivery systems
        • Typical use failure rates at 9% but higher in adolescent populations. Continuation rates are 67%, likely lower in adolescents; 99.9% effective with perfect use but real-life use, difficulties with adherence, and continuation significantly reduce effectiveness
        • Some estrogen-progestin agents such as combined oral contraceptive pills (COCs) and vaginal rings may be used almost continuously for extended cycling. Such extended cycling may be useful for patients with dysmenorrhea, heavy periods, anemia, or times (life events) when delaying a period desired.
      • COCs:
        • Monophasic COCs contain fixed doses of estrogens (ethinyl estradiol) and progestins. Phasic COCs vary doses of estrogens, progestins, or both; no practical difference between monophasic and phasic COCs
        • Benefits: reduce incidence of endometrial and ovarian cancers after as little as 3 months of use, protect against salpingitis (pelvic inflammatory disease [PID]) and subsequent ectopic pregnancies, and decrease incidence of benign breast disease and dysmenorrhea
        • Effective treatment for abnormal or heavy uterine bleeding (AUB), perimenstrual mood and physiologic symptoms, hygiene and behavior changes around menses for some developmentally delayed individuals, and sequelae of hyperandrogenism or polycystic ovary syndrome (AUB, hirsutism, acne)
      • Transdermal patch
        • Contains ethinyl estradiol and norelgestromin. Each patch left in place for 7 days, changed weekly, allowing 1 patch-free week per month for menses; convenient due to once-weekly change
        • Typically not recommended for extended cycling, as studies demonstrate 60% more circulating estrogen than with other estrogen-progestin methods
        • Unclear if this increases vascular thrombotic event (VTE) risk
      • Vaginal ring
        • Soft, flexible, polymer ring containing ethinyl estradiol and etonogestrel
        • FDA-approved for vaginal insertion for 3 weeks and then removed for 1 week for menses
        • May be effective over a 4-week insertion and for extended cycling
        • Benefits: avoids 1st-pass liver effects and lower hormone doses
    • Emergency contraceptives: postcoital contraceptives, “morning-after” pills
      • General issues:
        • Safe but less effective (estimated 75%) than other hormonal/inserted contraceptives
        • Not abortifacient but blocks ovulation, as do other hormonal methods of contraceptives
        • Advance provision improves patient use but does not decrease overall pregnancy rates over time.
        • May be offered to all women using short- or moderate-acting contraceptives
      • Ulipristal acetate (UPA) 30 mcg
        • Should be 1st-line option as efficacy seems less effected by timing and patient weight
        • Administered in a single oral dose up to 5 days post unprotected sex with equal effectiveness across time
        • Is more effective in overweight or obese women than progestin methods
        • Not carried by all pharmacies, both community and hospital-based as of 2015
        • Often requires insurance preauthorization (unlike progestin only methods) which may delay administration
      • Progesterone-only methods:
        • Most effective when used within 72 hours of intercourse; treatment less likely to be effective up to 5 days
        • Levonorgestrel administered one time at a dose of 1.5 mg available by prescription and over the counter in the United States
        • Male patients should be educated about the use of emergency contraceptives and may purchase this method over the counter as well.
      • Yuzpe method of emergency contraception with COCs
        • Consists of 100 mcg ethinyl estradiol + 0.5 mg levonorgestrel given with repeated second dose 12 hours later
        • This method has higher rates of nausea and vomiting.
        • Generally used as a matter of urgent timing, convenience and expense if a woman has a COC pack of pills at home and prefers to use these for her emergency contraception method because other methods are more effective and have fewer side effects
    • Additional contraceptive methods:
      • General issues:
        • Well-known but with significantly lower efficacy
        • Include barrier methods to sperm entry (male and female condoms, diaphragms)
      • Male condoms
        • 88% effective with typical use; likely higher failure rates in adolescents
        • Female condom and diaphragm are 79% and 88% effective, respectively.
        • Proper condom use can prevent transmission of sexually transmitted infections such as HIV, HPV, HSV, syphilis, Neisseria gonorrhoeae, and Chlamydia trachomatis.
        • Important to inform adolescents that condoms are superior for sexually transmitted infection (STI) prevention but inferior to other methods as a sole agent of contraception
      • Spermicidal agents
        • Include: foam, film, vaginal inserts, as well as nonoxynal-9 as the active agent most widely used
        • Only 72% effective in preventing pregnancy with typical use. May reduce transmission of C. trachomatis and N. gonorrhoeae; when used with condoms, overall efficacy 93% with typical use
        • Irritant effect linked in some high-risk populations with increased risk of HIV transmission
        • Spermicides must be inserted with each intercourse, near the time of intercourse; some formulations require 10 to 15 minutes for activation. Most have an unpleasant taste.
      • Progestin-only pills (POPs) (“mini-pill”)
        • Much less effective than most other hormonal methods, as effectiveness is highly dependent on perfect use
        • May offer some measure of benefit for women who are immediately postpartum (up to 6 months) and breastfeeding on demand
        • Typically not a good method for most women
      • Abstinence
        • Sexual activity is a normal part of adolescent and adult human development.
        • Abstinence or refraining from vaginal-penile sexual intercourse is the most effective way to prevent unintended or unwanted pregnancy as well as transmission of STIs. Provider counseling and recommendations should promote a 4-pronged approach to sexual decision making: personal maturity and readiness, thoughtful partner selection and communication, family planning and pregnancy prevention, as well as prevention of STIs.
ALERT
  • Advising women to abstain from all forms of physical intimacy may be both unrealistic and counterproductive in the context of their psychosocial development.
  • Providers should emphasize at every visit that only 100% use of condoms (or abstinence) protects against sexually transmitted diseases but is not the most effective form of birth control available.
  • All forms of birth control are not “equal”—long-acting reversible contraceptives are significantly more effective contraceptives than all other methods, even sterilization.
  • Long-acting reversible contraceptive implants are both highly desirable and well tolerated in all patients and should be offered as 1st-line contraceptives to all women at risk for unintended pregnancy.
  • Include male patients in discussions about both condom use as well as contraceptive use.

General Prevention

  • Encourage consistent use of latex condoms.
  • Patients using oral contraceptive pills may be strongly encouraged to cease tobacco use, but tobacco use does not preclude estrogen-progestin methods in women <35 years.

Pathophysiology

  • Combined estrogen-progestin hormonal therapy suppresses ovulation by directly decreasing release of hypothalamic gonadotropin-releasing hormone (GnRH) and pituitary follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
  • Progesterone thickens cervical mucus, thins the endometrium, and decreases tubal motility. Higher dose systemic progestins inhibit the hypothalamic-ovarian axis and halt ovulation.
  • Copper: Copper ions inhibit transtubal sperm migration and act in both an ovicidal and spermicidal way to prevent zygote formation.
  • Emergency contraception: Mechanisms of action include ovulation disruption, endometrial impairment to prevent implantation, and possibly sperm or ova transport alteration.
  • Spermicides (nonoxynol-9 and octoxynol-9) destroy sperm cell membranes. Most spermicidal preparations contain an inert base (foam, cream, or jelly) to support the spermicidal agent and provide a barrier to sperm entry.

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