Medical School · Year 2 · Reproductive · includes a quiz and discussion video

Lecture 10: Contraception

Unit 2.4: Reproductive System

Learning Objectives

By the end of this lecture, students will be able to:

1. Describe the mechanisms and effectiveness of various contraceptive methods
2. Explain combined hormonal contraceptive options and considerations
3. Describe progestin-only contraceptive methods
4. Explain long-acting reversible contraception (LARC)
5. Describe barrier methods and fertility awareness methods
6. Explain emergency contraception and permanent sterilization

Section 1: Contraception Overview and Effectiveness

Contraception, the deliberate prevention of pregnancy, is fundamental to reproductive autonomy. Understanding the diverse methods available, their mechanisms, effectiveness, benefits, and limitations enables informed patient counseling.

Effectiveness is the critical metric for comparing contraceptive methods and is expressed as the percentage of women experiencing unintended pregnancy within the first year of use. Perfect use reflects the failure rate with correct and consistent use, while typical use reflects real-world effectiveness accounting for human error. The substantial gap between perfect and typical use for some methods highlights the importance of user-independent contraception.

Methods can be organized into effectiveness tiers. The most effective tier includes long-acting reversible contraception (implant, hormonal and copper IUDs) and permanent sterilization, with typical use failure rates of less than 1%. These methods are "set and forget," requiring no ongoing user action. The second tier encompasses injectable contraception, combined hormonal contraceptives (pills, patch, ring), with typical use failure rates of 4-7%. User dependence introduces variability: missed pills, late injections, and improper patch or ring use contribute to failures. The third tier includes barrier methods (male and female condoms, diaphragm, cervical cap) and fertility awareness-based methods, with typical use failure rates of 12-24%. These methods require consistent use with every act of intercourse. The least effective tier includes withdrawal and spermicide alone, with typical use failure rates of 20-28%.

Selecting a contraceptive method involves considering multiple factors: effectiveness relative to the patient's desire to prevent pregnancy, reversibility and plans for future fertility, non-contraceptive benefits (menstrual regulation, acne treatment), potential side effects and medical contraindications, STI protection needs (only male and female condoms provide protection), and the patient's ability and willingness to use the method consistently. The US Medical Eligibility Criteria for Contraceptive Use (US MEC) provides evidence-based guidance on contraindications.

<image>Panel A: Top tier effectiveness (less than 1% failure) showing implant (0.05%), LNG-IUD (0.2%), copper IUD (0.8%), and sterilization (female 0.5%, male 0.15%) as user-independent "set and forget" methods. Panel B: Second tier (4-7% failure) showing DMPA injection (6%) and combined pill/patch/ring (7%), and third tier (12-24%) showing male condom (13%), diaphragm (17%), and fertility awareness methods (12-24%). Panel C: Perfect versus typical use comparison for selected methods highlighting the effectiveness gap (pill: 0.3% perfect vs 7% typical, condom: 2% perfect vs 13% typical), with bottom tier showing withdrawal (20%) and spermicide (21%). Panel D: Method selection factors checklist including effectiveness relative to pregnancy prevention desire, reversibility and future fertility plans, non-contraceptive benefits, side effects and contraindications, STI protection needs, and patient consistency ability.</image>

Section 2: Combined Hormonal Contraceptives - Methods and Mechanisms

Combined hormonal contraceptives (CHCs) contain both an estrogen and a progestin component, working synergistically to prevent pregnancy. Three delivery methods share this combination: oral contraceptives (pills), the transdermal patch, and the vaginal ring.

Combined oral contraceptives (COCs), the most widely used form, are taken daily. Monophasic formulations contain the same hormone doses throughout the active pills, while multiphasic formulations vary the doses to more closely mimic physiologic patterns. Most regimens include 21-24 active pills followed by 4-7 hormone-free or placebo days during which withdrawal bleeding occurs. Extended-cycle regimens (84 active pills followed by 7 hormone-free days) and continuous regimens (no hormone-free interval) reduce bleeding frequency.

The transdermal patch delivers hormones through the skin and is changed weekly for three weeks, followed by a patch-free week. The vaginal ring is inserted and remains in place for three weeks, then removed for one week. Both provide steady hormone levels without daily administration.

The estrogen component is most commonly ethinyl estradiol (EE), a synthetic estrogen resistant to first-pass hepatic metabolism. Doses range from 10 to 50 μg, with most modern formulations using 20-35 μg. Some newer formulations use estradiol valerate or estetrol. The progestin component varies; different progestins have differing androgenic, anti-androgenic, and anti-mineralocorticoid properties.

The mechanism of action involves multiple levels. Ovulation suppression is the primary mechanism: the combined hormones provide negative feedback to the hypothalamic-pituitary axis, inhibiting the LH surge necessary for ovulation. Secondary mechanisms include thickening of cervical mucus (progestin effect) that impedes sperm penetration, and changes in the endometrium that create a less favorable environment for implantation.

Non-contraceptive benefits are substantial. Menstrual benefits include reduced dysmenorrhea, lighter and more predictable bleeding, and treatment of heavy menstrual bleeding. CHCs reduce the risk of ovarian cysts, ovarian cancer (40-80% reduction with prolonged use), and endometrial cancer. Acne and hirsutism improve, particularly with low-androgenic or anti-androgenic progestins. Other benefits include reduced ectopic pregnancy risk and benign breast disease.

<image>Panel A: Three CHC delivery methods showing pill (blister pack with active and placebo pills), patch (application sites with weekly change schedule), and ring (vaginal placement cross-section, 3 weeks in/1 week out cycle). Panel B: Mechanism of action with hypothalamic-pituitary suppression providing negative feedback to block GnRH pulsatility and suppress LH surge preventing ovulation, plus cervical mucus thickening and endometrial changes. Panel C: Hormone components showing ethinyl estradiol molecule and progestin generations with properties (levonorgestrel as more androgenic, drospirenone as anti-androgenic/anti-mineralocorticoid), with dose ranges for estrogen (20-35 mcg). Panel D: Non-contraceptive benefits including reduced dysmenorrhea, lighter and more predictable periods, ovarian cancer protection (40-80% reduction), endometrial cancer reduction, and improved acne with low-androgenic progestins.</image>

Section 3: Combined Hormonal Contraceptives - Risks and Contraindications

The serious risks associated with combined hormonal contraceptives are primarily related to the estrogen component and involve the cardiovascular system.

Venous thromboembolism risk is increased 3-4 fold with CHC use, from a baseline of approximately 1-2 per 10,000 woman-years in reproductive-age women to 3-4 per 10,000 woman-years. This risk is highest in the first year of use, particularly the first three months. The progestin component modifies this risk: third-generation progestins (desogestrel, gestodene) and drospirenone carry slightly higher VTE risk than levonorgestrel. Transdermal patches may also carry higher risk due to higher systemic estrogen exposure.

Arterial thrombosis, including myocardial infarction and ischemic stroke, is a rare but serious complication. The absolute risk is very low in healthy young women but increases substantially with smoking, particularly in women over 35. Hypertension further amplifies risk.

Contraindications are classified by the US MEC using a four-category system. Category 4 conditions represent unacceptable health risks where CHCs should not be used. These include: current or past history of VTE; known thrombogenic mutations (Factor V Leiden, prothrombin mutation); current or history of ischemic heart disease or stroke; complicated valvular heart disease; hypertension ≥160/100 mmHg or with vascular disease; migraine with aura (at any age); breast cancer (current or within 5 years); severe cirrhosis or hepatocellular adenoma/carcinoma; age ≥35 years with smoking ≥15 cigarettes/day; and less than 21 days postpartum (VTE risk).

Category 3 conditions represent situations where risks generally outweigh benefits. These include: age ≥35 with smoking fewer than 15 cigarettes/day; hypertension 140-159/90-99 mmHg; migraine without aura in women over 35; gallbladder disease; and 21-42 days postpartum.

Drug interactions affecting efficacy are limited but important. Rifampin, a potent cytochrome P450 inducer, significantly reduces CHC effectiveness. Some anticonvulsants (phenytoin, carbamazepine, phenobarbital, topiramate at doses >200 mg/day) similarly reduce efficacy. Most antibiotics do not affect CHC effectiveness, despite common misconception.

<image>Panel A: VTE incidence bar graph comparing baseline (1-2 per 10,000), CHC users (3-4 per 10,000), pregnancy (5-20 per 10,000), and postpartum (40-65 per 10,000) for risk context, with highest risk in first year of use. Panel B: Arterial thrombosis showing MI and stroke risk multipliers by smoking and hypertension status, with absolute risk low in healthy young women but substantially increased with risk factors. Panel C: Category 4 contraindications displayed as warning cards: VTE history, thrombogenic mutations, stroke/MI history, migraine with aura at any age, breast cancer, severe hypertension (160/100 or greater), and smoking 15+ cigarettes/day at age 35+, plus less than 21 days postpartum. Panel D: Drug interactions showing rifampin and certain anticonvulsants (phenytoin, carbamazepine, phenobarbital, topiramate) reducing CHC efficacy through CYP450 induction, with antibiotics noted as having no significant interaction despite common misconception.</image>

Section 4: Progestin-Only Contraceptive Methods

Progestin-only contraceptives provide effective pregnancy prevention without the estrogen-related risks of combined methods, making them suitable for women with estrogen contraindications and for breastfeeding women.

Progestin-only pills (POPs, "mini-pills") contain a low dose of progestin, most commonly norethindrone 0.35 mg. Unlike COCs, which suppress ovulation consistently, traditional POPs suppress ovulation in only about 50% of cycles, relying primarily on cervical mucus thickening and endometrial changes. This makes consistent timing critical: traditional POPs must be taken within a 3-hour window daily. Newer POPs containing desogestrel or drospirenone provide more consistent ovulation suppression and a wider dosing window. Typical use effectiveness is somewhat lower than COCs (approximately 7% failure rate). Irregular bleeding is common, which limits acceptability for some women.

Depot medroxyprogesterone acetate (DMPA, Depo-Provera) is administered as an intramuscular or subcutaneous injection every 12 weeks. DMPA provides highly effective contraception (>99% with consistent use) by suppressing ovulation, thickening cervical mucus, and inducing endometrial atrophy. Side effects include irregular bleeding initially (often progressing to amenorrhea with continued use), weight gain (average 5-8 pounds over 2-3 years), mood changes, and decreased bone mineral density. The bone density effect is concerning but reversible after discontinuation; the FDA black box warning recommends limiting use to 2 years unless other methods are inadequate. Return to fertility is delayed, averaging 9-12 months after the last injection.

The etonogestrel implant (Nexplanon) is a single-rod device inserted subdermally in the upper arm that releases etonogestrel continuously for at least 3 years (FDA-approved; effective up to 5 years based on recent data). It is the most effective reversible contraceptive method, with a failure rate of 0.05%. The implant suppresses ovulation and thickens cervical mucus. Insertion and removal are minor office procedures. The primary side effect is unpredictable bleeding, which is the most common reason for discontinuation. Return to fertility is rapid after removal.

<image>Panel A: Progestin-only pill showing pill pack, dosing timing window (3-hour for traditional, wider for newer formulations), mechanism (50% ovulation suppression, 50% cervical mucus/endometrial changes), and irregular bleeding pattern. Panel B: DMPA injection showing injection site, 12-week calendar interval, strong ovulation suppression mechanism, side effects (weight gain, mood changes, bone density decrease with FDA black box warning), and delayed fertility return averaging 9-12 months. Panel C: Etonogestrel implant showing arm placement, 3-5 year duration, insertion procedure, 0.05% failure rate (most effective reversible method), ovulation suppression mechanism, variable bleeding pattern, and rapid fertility return after removal. Panel D: Comparison table showing typical use failure rates, contraindications, and breastfeeding compatibility for each progestin-only method, all safe immediately postpartum and during breastfeeding.</image>

Section 5: Intrauterine Devices (IUDs)

Intrauterine devices represent highly effective, long-acting, reversible contraception. Two types are available: the copper IUD and hormonal levonorgestrel-releasing IUDs.

The copper IUD (Paragard) is a T-shaped device with copper wire wrapped around the stem and arms. It is approved for 10 years of use, though data suggest effectiveness beyond this duration. The mechanism is primarily spermicidal: copper ions create an inflammatory response toxic to sperm and ova, preventing fertilization. The copper IUD is hormone-free, making it appropriate for women who cannot or prefer not to use hormonal methods. It is also the most effective method of emergency contraception when placed within 5 days of unprotected intercourse. Side effects include heavier menstrual bleeding and increased cramping, particularly in the first few months. These effects make it less suitable for women with heavy or painful periods at baseline.

Hormonal IUDs release levonorgestrel (LNG) locally within the uterus. Several options exist with varying sizes and hormone release rates: Mirena (52 mg LNG, approved for 8 years), Liletta (52 mg LNG, approved for 8 years), Kyleena (19.5 mg LNG, approved for 5 years), and Skyla (13.5 mg LNG, approved for 3 years). The primary mechanism is thickening of cervical mucus, making it impenetrable to sperm. Endometrial atrophy occurs from local progestin effect, and some women experience ovulation suppression, particularly with higher-dose devices. Systemic hormone absorption is minimal. A major benefit is reduction in menstrual bleeding; 20-50% of Mirena users become amenorrheic by one year, making hormonal IUDs excellent treatment for heavy menstrual bleeding. Irregular spotting is common in the first 3-6 months.

Insertion can be performed at any time in the menstrual cycle if pregnancy is reasonably excluded. The procedure involves a speculum exam, sounding the uterus to measure depth, and deploying the device through a narrow inserter. Cramping during and after insertion is common. Complications are rare: perforation occurs in less than 0.1% of insertions (risk is higher with recent delivery or breastfeeding), and expulsion occurs in 2-10% (higher in the immediate postpartum period).

Myths persist but have been disproven. IUDs are safe for nulliparous women and do not cause infertility. The slightly increased risk of pelvic inflammatory disease is limited to the first 20 days after insertion and relates to insertion technique rather than the device itself.

<image>Panel A: Copper IUD (Paragard) showing T-shaped device with copper wire, 10-year duration, spermicidal mechanism (copper ions creating toxic environment for sperm), hormone-free designation, side effects (heavier bleeding, increased cramping), and emergency contraception indication within 5 days. Panel B: Hormonal IUDs showing device shapes for Mirena/Liletta (52 mg LNG, 8 years) and Kyleena/Skyla (smaller, 5 and 3 years), mechanism (thick cervical mucus blocking sperm, endometrial atrophy), benefits (reduced bleeding, 20-50% amenorrhea rate), and initial spotting resolving over 3-6 months. Panel C: Insertion procedure steps (speculum, uterine sound, deployment), with complications including perforation (less than 0.1%) and expulsion (2-10%), and myth-busting confirmation that IUDs are safe for nulliparous women and do not cause infertility. Panel D: PID risk limited to first 20 days after insertion (related to technique, not device), with IUD candidacy regardless of parity and immediate return to fertility after removal.</image>

Section 6: Barrier Methods and Spermicides

Barrier methods physically prevent sperm from reaching the upper reproductive tract. They are user-dependent, requiring correct use with every act of intercourse, and provide the only contraceptive options that also protect against sexually transmitted infections.

Male condoms, the most widely used barrier method, are sheaths placed over the erect penis before intercourse. Latex condoms are most common and provide excellent STI protection, including against HIV. Polyurethane condoms are an alternative for latex allergy and also protect against STIs. Natural membrane (lambskin) condoms prevent pregnancy but do not protect against STIs due to pores that allow virus passage. Correct use involves placing the condom before any genital contact, leaving space at the tip for ejaculate, using only water- or silicone-based lubricants with latex (oil-based lubricants degrade latex), and withdrawing while still erect after ejaculation. Perfect use failure rate is 2%; typical use failure rate is 13%, reflecting inconsistent or incorrect use.

Female condoms are pouches inserted into the vagina before intercourse. They line the vaginal canal and partially cover the external genitalia, potentially offering better STI protection than male condoms for infections transmitted through skin contact. The current version is made of nitrile. They can be inserted up to 8 hours before intercourse. Perfect use failure rate is 5%; typical use failure rate is 21%.

The diaphragm is a dome-shaped silicone cup inserted into the vagina to cover the cervix. It must be used with spermicide and left in place for at least 6 hours after intercourse. The Caya diaphragm is a one-size-fits-most option that does not require fitting. Perfect use failure rate is 6%; typical use failure rate is 17%.

The cervical cap (FemCap) is smaller than a diaphragm and fits directly over the cervix. Effectiveness varies by parity, with higher failure rates in parous women.

Spermicides contain nonoxynol-9, which immobilizes and kills sperm. Available as foam, gel, film, or suppositories, spermicides are inserted before intercourse. When used alone, effectiveness is low (21% typical use failure). Spermicides do not protect against STIs and may increase HIV transmission risk due to mucosal irritation.

<image>Panel A: Male condom showing placement technique, materials comparison (latex with STI protection, polyurethane for latex allergy with STI protection, lambskin without STI protection), correct use steps with lubricant compatibility, and failure rates (2% perfect, 13% typical). Panel B: Female condom showing insertion diagram with inner and outer rings, nitrile material, timing flexibility (up to 8 hours before intercourse), potential STI coverage advantage for skin-contact infections, and failure rates (5% perfect, 21% typical). Panel C: Diaphragm showing dome-shaped device placement covering cervix, use with spermicide, 6-hour post-intercourse timing requirement, and Caya one-size-fits-most option, plus cervical cap with parity-dependent effectiveness. Panel D: Spermicides showing various forms (foam, gel, film, suppository), nonoxynol-9 active ingredient, low effectiveness alone (21% typical use), no STI protection, and warning about potential increased HIV transmission risk from mucosal irritation.</image>

Section 7: Fertility Awareness-Based Methods

Fertility awareness-based methods (FABMs) rely on identifying the fertile window—the days when intercourse can result in pregnancy—and avoiding unprotected intercourse during that time. These methods require no hormones or devices but demand education, motivation, and consistent tracking.

The fertile window spans approximately six days: the five days preceding ovulation (reflecting sperm survival time) plus the day of ovulation (the oocyte remains viable for only about 24 hours). Accurately identifying this window is the key challenge.

Calendar-based methods use cycle length history to predict the fertile window. The standard days method is simplest: for women with cycles consistently 26-32 days, days 8-19 are considered fertile. The rhythm method uses mathematical calculations based on past cycle lengths. These methods have limited accuracy because ovulation timing varies.

Basal body temperature (BBT) tracking exploits the 0.2-0.5°C rise in temperature that occurs after ovulation due to progesterone's thermogenic effect. Temperature must be taken immediately upon waking, before any activity. The temperature rise confirms ovulation retrospectively but does not predict it, making BBT most useful for identifying the infertile post-ovulatory phase.

Cervical mucus monitoring (Billings method) tracks changes in cervical secretions throughout the cycle. As estrogen rises before ovulation, mucus becomes abundant, clear, slippery, and stretchy (similar to raw egg white)—this "peak" mucus indicates high fertility. After ovulation, progesterone causes mucus to become scant, sticky, and opaque. Recognizing mucus changes requires training.

The symptothermal method combines BBT, cervical mucus observation, and sometimes cervical position assessment. This multiparameter approach provides higher effectiveness than single-indicator methods, with perfect use failure rates as low as 1-2%.

Considerations for FABMs include their acceptability to couples who prefer "natural" methods or have religious objections to other contraception, the requirement for partner cooperation, the need for training and discipline, and reduced effectiveness with irregular cycles. Mobile apps have made tracking easier, though app-based predictions alone (without symptom observation) have limited accuracy.

<image>Panel A: Menstrual cycle timeline with fertile window (days 8-19 shaded for standard days method), calendar-based approaches including standard days method cycle chart and rhythm method calculations. Panel B: Basal body temperature tracking showing BBT graph across the cycle with baseline, ovulation day, and post-ovulatory rise (0.2-0.5 degrees C), noting the rise is retrospective and identifies the infertile post-ovulatory phase. Panel C: Cervical mucus changes showing visual comparison across the cycle from dry/sticky post-menses to abundant clear stretchy peak mucus at ovulation (spinnbarkeit test) to scant sticky post-ovulation, plus symptothermal method combining multiple indicators to identify the fertile window. Panel D: Effectiveness comparison table showing perfect and typical use rates for each method (symptothermal 1-2% perfect use), with considerations including partner cooperation, training requirements, reduced effectiveness with irregular cycles, and mobile app limitations.</image>

Section 8: Emergency Contraception

Emergency contraception (EC) prevents pregnancy after unprotected intercourse or contraceptive failure. It is not a regular contraceptive method but a backup option. Three main options exist: oral levonorgestrel, oral ulipristal acetate, and the copper IUD.

Levonorgestrel (Plan B One-Step and generics) is available over-the-counter without age restriction. The single 1.5 mg dose should be taken as soon as possible after unprotected intercourse. The primary mechanism is delaying or inhibiting ovulation; it has no effect once ovulation has occurred and does not disrupt an established pregnancy. Effectiveness decreases with time: when taken within 72 hours, it reduces pregnancy risk by approximately 89%, but effectiveness continues up to 120 hours (5 days) at reduced efficacy. Effectiveness is reduced in women with BMI greater than 25-30 kg/m². No contraindications exist.

Ulipristal acetate (ella) is a selective progesterone receptor modulator requiring a prescription. The 30 mg dose is taken as a single dose within 120 hours of unprotected intercourse. Unlike levonorgestrel, ulipristal can delay ovulation even after the LH surge has begun, providing more consistent effectiveness through day 5. It is more effective than levonorgestrel, particularly at days 4-5 and in women with higher BMI. Women should wait 5 days after taking ulipristal before starting hormonal contraception (which could reduce ulipristal's effectiveness).

The copper IUD is the most effective form of emergency contraception, reducing pregnancy risk by more than 99% when inserted within 5 days of unprotected intercourse. The mechanism includes interference with fertilization and possibly implantation. A major advantage is the provision of ongoing, highly effective contraception. It requires provider insertion and is not appropriate for women with current STI.

Mechanisms of emergency contraception do not include disruption of an established pregnancy. EC prevents pregnancy primarily by delaying or inhibiting ovulation. If fertilization has already occurred, EC is not effective.

Following EC use, patients should be counseled to begin or resume regular contraception immediately (for levonorgestrel) or after 5 days (for ulipristal). A pregnancy test is indicated if menses are delayed by more than one week.

<image>Panel A: Levonorgestrel (Plan B) showing pill with OTC availability, 1.5 mg single dose, timing effectiveness curve (highest at day 1, declining through day 5, 89% risk reduction within 72 hours), mechanism of delaying ovulation, and reduced efficacy with BMI greater than 25-30. Panel B: Ulipristal acetate (ella) showing prescription required, 30 mg single dose, more sustained effectiveness through day 5 especially at days 4-5 and higher BMI, mechanism of delaying ovulation even after LH surge begins, and 5-day wait before starting hormonal contraception. Panel C: Copper IUD showing device with greater than 99% effectiveness within 5 days of unprotected intercourse, mechanism of interfering with fertilization, advantage of ongoing highly effective contraception, and requirement for provider insertion. Panel D: Mechanism clarification showing EC does not disrupt established pregnancy and acts before fertilization, with follow-up counseling points including resuming contraception and pregnancy testing if menses delayed by more than one week.</image>

Section 9: Permanent Contraception - Sterilization

Sterilization provides permanent contraception for individuals or couples who have completed childbearing. Both female and male options exist, with male sterilization (vasectomy) being simpler, safer, and less expensive.

Female sterilization traditionally involved tubal ligation—surgical interruption of the fallopian tubes by various techniques including clips, rings, electrocoagulation, or partial salpingectomy. These procedures can be performed postpartum (through a minilaparotomy incision), at the time of cesarean delivery, or at interval (typically laparoscopically). Failure rates are approximately 0.5% (1 in 200) over 10 years, with the CREST study demonstrating that failures are more common with certain techniques and younger age at sterilization.

Bilateral salpingectomy (complete removal of both fallopian tubes) has increasingly replaced tubal ligation. Evidence that many ovarian cancers originate in the fimbriated end of the fallopian tube has prompted this shift, as salpingectomy appears to reduce ovarian cancer risk by 40-60%. Salpingectomy also has a lower failure rate than tubal ligation.

Hysteroscopic sterilization (Essure) was available as an office procedure but was withdrawn from the market in 2019 due to complications and patient concerns.

Vasectomy involves interruption of the vas deferens, preventing sperm from reaching the ejaculate. It is performed as an outpatient procedure under local anesthesia through one or two small scrotal incisions or punctures. Techniques include conventional incisional and no-scalpel approaches. Complications are uncommon and typically minor (hematoma, infection, chronic pain in rare cases). Vasectomy is more effective than female sterilization, with failure rates of approximately 0.15%. Importantly, vasectomy is not immediately effective; sperm remain in the reproductive tract for several months. A semen analysis at 3 months (or after 20 ejaculations) confirming azoospermia is required before relying on vasectomy alone.

Counseling for sterilization emphasizes permanence. While reversal is sometimes possible, it is expensive, not always successful, and should not be relied upon. Patients should be informed that while sterilization is highly effective, rare failures occur. Regret is more common in younger patients, those who make the decision during times of stress, and those who experience relationship changes. For patients desiring permanent contraception, LARC methods offer equivalent effectiveness with reversibility.

<image>Panel A: Female sterilization surgical approaches showing postpartum minilaparotomy (incision near umbilicus with tube exteriorized), laparoscopic interval procedure (trocar ports, clip/ring/cautery), and cesarean timing, with tubal ligation techniques (clips, rings, partial salpingectomy) and failure rate comparison. Panel B: Bilateral salpingectomy (complete tubal removal) highlighted as increasingly preferred approach with 40-60% ovarian cancer risk reduction and lower failure rate than traditional tubal ligation. Panel C: Vasectomy showing anatomy (vas deferens path), no-scalpel technique in office setting under local anesthesia, 0.15% failure rate (more effective than female sterilization), and 3-month semen analysis requirement before relying on method alone. Panel D: Counseling points emphasizing permanence, reversal limitations (expensive, not always successful), regret risk factors (younger age, relationship stress, decision during crisis), and LARC as alternative offering equivalent effectiveness with reversibility.</image>

Section 10: Special Populations and Medical Eligibility

Contraceptive counseling must be individualized, considering patient characteristics, medical conditions, and life circumstances. The US Medical Eligibility Criteria for Contraceptive Use provides evidence-based guidance.

Adolescents require confidential, non-judgmental counseling. LARC methods are recommended as first-line options due to their superior effectiveness and lack of user-dependent failure. Dual protection (condom plus another method) addresses both pregnancy and STI prevention. Access barriers, including cost and confidentiality concerns, should be addressed.

Postpartum women need timely contraception, as ovulation can return within weeks of delivery. Immediate postpartum insertion of IUDs or implants provides effective contraception before hospital discharge. Progestin-only methods are safe immediately postpartum, including during breastfeeding. Combined hormonal contraceptives should be delayed until 21-42 days postpartum due to elevated VTE risk, and until 4-6 weeks if breastfeeding due to potential effects on milk supply. Estrogen does not affect breast milk volume or composition once lactation is established (typically by 6 weeks).

Perimenopausal women can still conceive until menopause is confirmed. Contraception should continue until 12 months of amenorrhea in women over 50 or 24 months in women under 50. Non-contraceptive benefits of hormonal methods (cycle regulation, vasomotor symptom improvement) may be particularly valuable.

Medical conditions require careful consideration. Women with migraine with aura should not use estrogen-containing methods due to increased stroke risk. Hypertension severity determines CHC eligibility. Diabetes without vascular complications generally does not restrict contraceptive options. Obesity does not contraindicate most methods, though effectiveness of certain methods (EC with levonorgestrel) may be reduced. Women living with HIV can use most contraceptive methods, with attention to drug interactions between hormonal contraceptives and certain antiretroviral agents.

The US MEC categorizes conditions from 1 (no restriction) to 4 (unacceptable health risk). Category 3 conditions warrant careful consideration of alternatives, while Category 4 conditions contraindicate use.

<image>Panel A: Adolescent contraception showing LARC as first-line recommendation for superior effectiveness, dual protection (condom plus another method) for STI prevention, and addressing confidentiality and access barriers. Panel B: Postpartum contraception timing showing immediate options (IUD and implant insertion in hospital), progestin-only methods (immediate, safe with breastfeeding), and combined hormonal timing (21-42 days postpartum, 4-6 weeks if breastfeeding). Panel C: Perimenopause showing fertility persistence until confirmed menopause (12 months amenorrhea over age 50, 24 months under 50), with non-contraceptive benefits of hormonal methods for cycle regulation and vasomotor symptoms. Panel D: Medical conditions quick reference showing migraine with aura (no estrogen), hypertension (severity determines CHC eligibility), diabetes (most methods acceptable without vascular complications), obesity (most methods appropriate, EC efficacy note), with US MEC categories 1-4 explained.</image>

Summary

Contraceptive effectiveness varies dramatically between methods. LARC (implant, IUDs) and sterilization are most effective (<1% failure). User-dependent methods have significant gaps between perfect and typical use effectiveness.

Combined hormonal contraceptives (pill, patch, ring) suppress ovulation through estrogen-progestin negative feedback. Benefits include menstrual regulation and reduced ovarian/endometrial cancer risk. Major risks are VTE and arterial thrombosis, with absolute contraindications including VTE history, migraine with aura, smoking in women ≥35, and severe hypertension.

Progestin-only methods (POP, DMPA, implant) are safe for women with estrogen contraindications. DMPA suppresses ovulation but has bone density effects and delayed fertility return. The implant is the most effective reversible contraceptive.

IUDs include copper (hormone-free, heavier bleeding, 10 years, effective EC) and hormonal (reduced bleeding, 3-8 years depending on type). Both are safe for nulliparous women and do not cause infertility.

Barrier methods (condoms, diaphragm) require consistent use and provide STI protection (condoms only).

Emergency contraception includes levonorgestrel (OTC, within 72-120 hours), ulipristal (prescription, more effective at days 4-5 and with higher BMI), and copper IUD (most effective, ongoing contraception).

Sterilization is permanent. Vasectomy is safer and more effective than tubal procedures. Bilateral salpingectomy may reduce ovarian cancer risk.

Key Terms

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