Medical School · Year 3 · Obgyn · includes a quiz and discussion video

Seminar 12: Contraception

OB/GYN Clerkship

Learning Objectives

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

1. Compare contraceptive method effectiveness using perfect and typical use failure rates and identify long-acting reversible methods as first-line options
2. Describe combined hormonal contraceptive formulations, non-contraceptive benefits, and serious adverse effects
3. Apply the US Medical Eligibility Criteria to determine safe contraceptive options for patients with medical comorbidities
4. Explain progestin-only contraceptive options including pills, injectable depot medroxyprogesterone acetate, and the subdermal implant
5. Counsel patients on intrauterine device types, insertion, eligibility, and management of complications
6. Provide emergency contraception and counsel on permanent sterilization options for both female and male patients

Seminar Outline

Section 1: Contraceptive Effectiveness

Contraceptive effectiveness is measured using both perfect use and typical use failure rates, and understanding this distinction is essential for patient counseling. Perfect use rates represent the method's efficacy when used exactly as directed, while typical use rates account for real-world adherence challenges such as missed pills or inconsistent condom use. The most effective methods are those that are user-independent, including the subdermal implant and intrauterine devices, all of which achieve greater than 99 percent effectiveness with both perfect and typical use. The injectable contraceptive has greater than 99 percent perfect use efficacy but only 94 percent typical use due to delayed return visits, while the pill, patch, and ring have greater than 99 percent perfect use but only 91 percent typical use. Barrier methods demonstrate the widest gap between perfect and typical use, with the male condom at 98 percent perfect versus 82 percent typical use, and the female condom at 95 percent perfect versus 79 percent typical use.

Long-acting reversible contraception encompasses methods that provide highly effective, user-independent pregnancy prevention for extended durations. The copper intrauterine device provides 10 to 12 years of non-hormonal contraception, while hormonal intrauterine devices offer 3 to 7 years of protection depending on the specific device. The etonogestrel subdermal implant provides 3 years of contraception and is the single most effective reversible contraceptive method available. The primary advantage of long-acting reversible contraception is the elimination of user-dependent adherence, which accounts for the minimal difference between perfect and typical use failure rates. Current guidelines from the American College of Obstetricians and Gynecologists recommend long-acting reversible contraception as first-line options for most women, including adolescents and nulliparous patients.

Contraceptive counseling is grounded in the principles of shared decision-making, patient autonomy, and reproductive justice. The clinician should present options in a balanced manner that centers patient preferences and values, avoiding directive counseling that may infringe on reproductive autonomy. Discussion of effectiveness should include both the Pearl index, expressed as pregnancies per 100 woman-years, and typical use rates that more accurately reflect real-world experience. Non-contraceptive benefits such as menstrual regulation, acne improvement, and cancer risk reduction should be discussed alongside side effects with realistic expectations set from the outset. Practical considerations including cost, insurance coverage, pharmacy access, and the need for a clinic visit for initiation or removal influence method selection and should be addressed during counseling.

Method continuation is a critical outcome that determines the long-term effectiveness of any contraceptive method. Side effects represent the most common reason for contraceptive discontinuation, and thorough pre-initiation counseling about expected side effects such as irregular bleeding has been shown to improve continuation rates. Long-acting reversible contraception has the highest continuation rates of any reversible method, with one-year continuation exceeding 80 percent for intrauterine devices and the implant. Patient satisfaction is closely linked to whether the experience matches expectations, underscoring the importance of honest and comprehensive counseling. Clinicians should schedule follow-up to address concerns and provide reassurance during the adjustment period, particularly during the first three to six months when irregular bleeding is most common with hormonal methods.

<image>Panel A: Contraceptive effectiveness spectrum showing perfect and typical use failure rates for implant, IUDs, injection, pill/patch/ring, condoms, withdrawal, fertility awareness, and spermicide arranged from most to least effective. Panel B: Long-acting reversible contraception comparison showing copper IUD (10 to 12 years), hormonal IUDs (3 to 7 years), and implant (3 years) with their mechanisms and effectiveness rates. Panel C: Shared decision-making counseling framework illustrating patient preferences, effectiveness discussion, non-contraceptive benefits, side effect expectations, and access considerations. Panel D: Method continuation rate graph showing one-year continuation percentages for LARC methods (greater than 80 percent), pills (67 percent), injection (56 percent), and condoms (43 percent) with side effects as primary discontinuation driver.</image>

Section 2: Combined Hormonal Contraception

Combined hormonal contraception contains both an estrogen and a progestin component that work synergistically to prevent pregnancy. The estrogen component is most commonly ethinyl estradiol, though newer formulations contain estetrol, a natural estrogen with a potentially improved safety profile. The progestin component varies widely among formulations, with commonly used types including norethindrone, levonorgestrel, and drospirenone, each with distinct androgenic, anti-androgenic, or anti-mineralocorticoid properties. The primary mechanism of action involves suppression of ovulation through inhibition of the hypothalamic-pituitary-ovarian axis, with additional effects including thickening of cervical mucus to impede sperm transport and thinning of the endometrium to reduce the likelihood of implantation.

Combined hormonal contraception is available in three delivery methods that share similar efficacy and side effect profiles but differ in their dosing schedules. The oral contraceptive pill is taken daily and is available in various regimens including the traditional 21/7 schedule with 21 active pills and 7 placebo days, the 24/4 regimen that shortens the hormone-free interval, and extended or continuous regimens that minimize or eliminate withdrawal bleeding. The transdermal patch is applied weekly for three consecutive weeks followed by a patch-free week, providing consistent hormone delivery through the skin. The vaginal ring is inserted and worn for three weeks followed by removal for one week, offering the convenience of monthly rather than daily dosing and producing stable serum hormone levels with lower peak concentrations.

The non-contraceptive benefits of combined hormonal contraception are numerous and may serve as additional indications for use in some patients. Menstrual regulation produces lighter, more predictable periods, which is beneficial for women with heavy or irregular bleeding. Dysmenorrhea is significantly reduced due to decreased prostaglandin production from a thinner endometrium. Acne improvement occurs particularly with formulations containing anti-androgenic progestins such as drospirenone. Endometriosis symptoms are managed through endometrial suppression, and long-term use provides significant risk reduction for ovarian cancer (40 to 50 percent reduction with 5 or more years of use) and endometrial cancer (50 percent reduction that persists for years after discontinuation).

Side effects of combined hormonal contraception range from common minor complaints to rare serious adverse events. Common side effects include nausea, breast tenderness, breakthrough bleeding (particularly in the first one to three months), headache, and mood changes, most of which improve with continued use. The serious adverse events are primarily related to the prothrombotic effect of exogenous estrogen and include venous thromboembolism, stroke, and myocardial infarction. The absolute risk of venous thromboembolism in combined hormonal contraceptive users is approximately 3 to 9 per 10,000 woman-years compared to 1 to 5 per 10,000 in non-users and 5 to 20 per 10,000 during pregnancy. These serious risks are concentrated in women with additional risk factors and form the basis for the medical eligibility criteria that guide safe prescribing.

<image>Panel A: Combined hormonal contraception components showing estrogen types (ethinyl estradiol, estetrol) and progestin types (norethindrone, levonorgestrel, drospirenone) with their distinct pharmacologic properties and mechanism of action through ovulation suppression. Panel B: Delivery method comparison showing daily oral pill (21/7, 24/4, extended), weekly transdermal patch (3 weeks on, 1 week off), and monthly vaginal ring (3 weeks in, 1 week out) with dosing schedules. Panel C: Non-contraceptive benefits diagram showing menstrual regulation, dysmenorrhea reduction, acne improvement, endometriosis symptom control, ovarian cancer risk reduction (40 to 50 percent), and endometrial cancer risk reduction (50 percent). Panel D: Risk-benefit profile showing common side effects (nausea, breast tenderness, breakthrough bleeding) alongside serious risks (VTE, stroke, MI) with absolute VTE incidence rates for non-users, users, and pregnant women.</image>

Section 3: Combined Hormonal Contraindications

Absolute contraindications to combined hormonal contraception are classified as US Medical Eligibility Criteria Category 4, indicating an unacceptable health risk. These include a history of current or past venous thromboembolism, known inherited thrombophilia such as Factor V Leiden or prothrombin gene mutation, and smoking 15 or more cigarettes per day in women aged 35 and older. Migraine with aura at any age is an absolute contraindication due to the increased risk of ischemic stroke, as is uncontrolled hypertension with systolic blood pressure of 160 or higher or diastolic of 100 or higher. Current breast cancer, severe liver disease including hepatic adenoma or hepatocellular carcinoma, and the early postpartum period within 21 days of delivery are also Category 4 contraindications. Clinicians must screen for all of these conditions before prescribing any estrogen-containing contraceptive.

Relative contraindications are classified as US Medical Eligibility Criteria Category 3, in which the risks of the method usually outweigh the benefits but use may be considered in certain circumstances. These include smoking fewer than 15 cigarettes per day in women aged 35 and older, adequately controlled hypertension, and migraine without aura in women aged 35 and older. The postpartum period from 21 to 42 days and breastfeeding in the first 6 weeks postpartum are Category 3 due to concerns about thrombotic risk and potential effects on milk supply respectively. Symptomatic gallbladder disease and certain medication interactions also fall into this category. When a Category 3 condition is present, the clinician should counsel the patient about the elevated risks and explore alternative methods, particularly progestin-only or non-hormonal options that do not carry estrogen-related risks.

The US Medical Eligibility Criteria provide a systematic framework for evaluating contraceptive safety across a wide range of medical conditions. Category 1 indicates no restriction for use of the method, while Category 2 indicates that the benefits generally outweigh the risks and the method can be used. Category 3 indicates that the risks usually outweigh the benefits, and the method is generally not recommended unless other options are unavailable or unacceptable. Category 4 indicates an unacceptable health risk, and the method should not be used. This framework allows clinicians to make evidence-based decisions about contraceptive safety for patients with complex medical histories, and the complete reference is available through the Centers for Disease Control and Prevention.

Initiation of combined hormonal contraception can follow several timing approaches depending on clinical context. The quick start method allows the patient to begin the method at any time in her cycle as long as pregnancy can be reasonably excluded, improving access and reducing the chance that the patient will not return to start the method. The Day 1 start involves beginning on the first day of menstrual bleeding, which provides immediate contraceptive protection without the need for backup. The Sunday start, beginning on the first Sunday after the onset of menses, is a traditional approach that ensures withdrawal bleeding occurs on weekdays. When starting outside the first 5 days of the menstrual cycle, a backup method such as condoms is recommended for the first 7 days while ovulation suppression is established.

<image>Panel A: Category 4 absolute contraindications displayed as warning icons for VTE history, thrombophilia, smoking at 35 or older (15 or more cigarettes), migraine with aura, uncontrolled hypertension, breast cancer, liver disease, and postpartum less than 21 days. Panel B: Category 3 relative contraindications showing smoking at 35 or older (fewer than 15 cigarettes), controlled hypertension, migraine without aura at 35 or older, postpartum 21 to 42 days, breastfeeding under 6 weeks, and gallbladder disease. Panel C: US Medical Eligibility Criteria category system with definitions for Category 1 (no restriction), Category 2 (benefits outweigh risks), Category 3 (risks outweigh benefits), and Category 4 (unacceptable risk). Panel D: Starting method options showing quick start (any time, backup 7 days), Day 1 start (immediate protection), and Sunday start (traditional timing) with decision algorithm for selecting approach.</image>

Section 4: Progestin-Only Contraception

The progestin-only pill, commonly known as the mini-pill, provides contraception primarily through thickening of cervical mucus rather than reliable ovulation suppression. Traditional formulations containing norethindrone require strict adherence to a 3-hour dosing window, and any deviation from this window necessitates backup contraception for 48 hours. Efficacy is somewhat lower than combined oral contraceptive pills when adherence is imperfect, making this a less forgiving option for patients with irregular schedules. The newer drospirenone progestin-only pill offers a 24-hour dosing window and more consistent ovulation suppression, representing a significant improvement in both efficacy and convenience. Irregular bleeding is the most common side effect of progestin-only pills and is the primary reason for discontinuation.

Injectable depot medroxyprogesterone acetate provides highly effective contraception administered as 150 milligrams intramuscularly every 13 weeks. When injections are received on time, efficacy is excellent, but the 94 percent typical use rate reflects the reality that many patients miss or delay appointments. Side effects include irregular bleeding that often progresses to amenorrhea with continued use, weight gain averaging 5 to 8 pounds over the first year, mood changes, and headache. Depot medroxyprogesterone acetate is associated with a reversible decrease in bone mineral density, which is a consideration particularly for adolescents and women who plan extended use, though current guidelines do not limit the duration of use. Return to fertility may be delayed 10 to 18 months after the last injection, which should be discussed with patients who may desire pregnancy in the near future.

The etonogestrel subdermal implant is a single rod inserted subdermally in the medial upper arm that provides the most effective reversible contraception available for up to 3 years. Insertion and removal are performed in the office under local anesthesia, and proper placement is confirmed by palpation of the rod beneath the skin. The primary mechanism is ovulation suppression, supplemented by cervical mucus thickening and endometrial thinning. Irregular bleeding is the most common side effect and the primary reason for discontinuation, though many women eventually develop lighter bleeding or amenorrhea. The implant is particularly well-suited for patients who desire highly effective, low-maintenance contraception and for those who cannot use estrogen-containing methods.

Progestin-only contraception offers several important advantages that make it suitable for patients with contraindications to estrogen. Because progestins do not carry the estrogen-related risk of venous thromboembolism, they are safe for women with a history of thrombosis, known thrombophilia, or other conditions classified as Category 4 for combined hormonal contraception. Progestin-only methods are safe during breastfeeding and can be initiated immediately postpartum without concerns about milk supply or neonatal exposure. Women with migraine with aura, who are absolutely contraindicated for estrogen-containing methods, can safely use any progestin-only option. The venous thromboembolism risk is not increased with progestin-only contraception, making these methods a versatile choice for a wide range of patients with complex medical conditions.

<image>Panel A: Progestin-only pill comparison showing traditional norethindrone formulation with 3-hour dosing window and cervical mucus mechanism versus newer drospirenone formulation with 24-hour window and improved ovulation suppression. Panel B: Injectable DMPA profile showing 150 milligram intramuscular dose every 13 weeks, bleeding pattern progression from irregular to amenorrhea, bone density considerations, and 10 to 18 month delayed fertility return. Panel C: Subdermal implant illustration showing single etonogestrel rod placement in medial upper arm with insertion technique, 3-year duration, and mechanism of ovulation suppression with cervical mucus thickening. Panel D: Progestin-only advantages checklist showing safety in estrogen contraindications (VTE history, thrombophilia), breastfeeding compatibility, migraine with aura safety, and no increased thromboembolism risk.</image>

Section 5: Intrauterine Devices

Intrauterine devices are available in two fundamental categories with distinct mechanisms and clinical profiles. The copper intrauterine device provides 10 to 12 years of non-hormonal contraception through a spermicidal inflammatory reaction created by copper ions in the uterine cavity, which is toxic to sperm and prevents fertilization. The levonorgestrel-releasing intrauterine devices are available in three formulations: the 52-milligram device providing 7 years of use, the 19.5-milligram device for 5 years, and the 13.5-milligram device for 3 years. The hormonal devices work primarily through local progestin effects including cervical mucus thickening, endometrial thinning, and partial ovulation suppression, with the higher-dose devices providing more consistent ovulation inhibition.

Intrauterine device insertion follows a standardized procedural protocol that can be performed at any point in the menstrual cycle after pregnancy has been excluded. Informed consent includes discussion of benefits, risks, alternatives, and the procedural experience. The technique involves sounding the uterus to determine depth and direction, then advancing the device through the cervix and into the fundus using the specific insertion device provided with each system. After deployment, the strings are trimmed to a length of approximately 3 to 4 centimeters from the external cervical os, and the string length is documented. Post-insertion follow-up typically includes a string check and symptom assessment, with patients instructed to report warning signs including persistent pain, fever, abnormal discharge, or inability to feel the strings.

Side effects differ significantly between the copper and hormonal intrauterine devices, which is an important consideration in method selection. The copper intrauterine device is associated with heavier menstrual periods and increased cramping, particularly during the first several months, and these side effects are the primary reason for discontinuation. The hormonal intrauterine devices, conversely, produce lighter periods and frequently result in amenorrhea, with the 52-milligram device reducing menstrual blood loss by approximately 90 percent at one year. Spotting and irregular bleeding may occur during the first 3 to 6 months with hormonal devices before bleeding patterns improve. Hormonal side effects such as headache, acne, and mood changes are possible but less common than with systemic hormonal methods due to the predominantly local action of the device.

Complications of intrauterine device use are uncommon but require recognition and appropriate management. Expulsion occurs in 2 to 10 percent of patients, with the highest risk during the first year and during menstruation, and is recognized by lengthening or absence of strings or partial device visualization at the cervical os. Uterine perforation is rare, occurring in approximately 1 per 1000 insertions, and may require surgical removal if the device migrates into the peritoneal cavity. Infection risk is limited to the first 20 days after insertion and reflects the introduction of vaginal flora during the procedure rather than an ongoing risk from the device itself. If pregnancy occurs with an intrauterine device in situ, ectopic pregnancy must be excluded, and if an intrauterine pregnancy is confirmed, the device should be removed if the strings are visible to reduce the risk of miscarriage and infection.

<image>Panel A: IUD type comparison showing copper IUD (10 to 12 years, spermicidal inflammatory mechanism, no hormones) versus levonorgestrel IUDs at three dose levels (52 mg for 7 years, 19.5 mg for 5 years, 13.5 mg for 3 years) with local progestin effects. Panel B: IUD insertion procedure sequence showing uterine sounding, device loading, transcervical advancement, fundal deployment, string trimming, and post-insertion documentation. Panel C: Side effect comparison showing copper IUD (heavier periods, increased cramping) versus hormonal IUD (lighter periods, eventual amenorrhea, initial spotting) with expected timelines. Panel D: Complication management showing expulsion (2 to 10 percent, string assessment), perforation (1 per 1000, surgical removal), infection (first 20 days risk), and pregnancy management (exclude ectopic, remove if strings visible).</image>

Section 6: IUD Eligibility

Good candidates for intrauterine device use encompass a much broader population than was historically recognized, reflecting updated evidence that has dispelled many previous misconceptions. Nulliparous women are excellent candidates for all intrauterine device types, and nulliparity is no longer considered a contraindication. Adolescents benefit particularly from the high efficacy and user-independent nature of intrauterine devices, and professional organizations including the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists endorse intrauterine devices as first-line options for this population. Postpartum insertion can be performed immediately after delivery or at a standard interval visit, and post-abortion insertion is safe and effective, with immediate placement associated with higher continuation rates. Women who are breastfeeding and those with contraindications to estrogen can safely use both copper and hormonal intrauterine devices.

True contraindications to intrauterine device insertion are limited to a defined set of conditions that compromise the safety of the device or the procedure. Current pregnancy must be excluded before insertion, and active pelvic inflammatory disease or purulent cervicitis must be treated before placement. Unexplained vaginal bleeding should be evaluated before insertion to exclude malignancy, as the device could mask ongoing pathology. Current cervical or endometrial cancer is a contraindication until treatment is completed. A significantly distorted uterine cavity from congenital anomalies or large submucosal fibroids may prevent proper device placement and increases the risk of expulsion or perforation. Wilson disease is a specific contraindication to the copper device due to disordered copper metabolism.

Common myths about intrauterine devices have been debunked by robust clinical evidence and should be addressed during patient counseling. The historical association between intrauterine devices and pelvic inflammatory disease was driven by the Dalkon Shield, a device withdrawn from the market in the 1970s, and modern devices carry only a slight infection risk limited to the first 20 days after insertion. Intrauterine devices do not increase the risk of ectopic pregnancy; rather, they reduce all pregnancies, though if contraceptive failure occurs, the proportion of pregnancies that are ectopic is higher than in unprotected women. There is no evidence that intrauterine devices cause infertility, and fertility returns promptly after removal. The belief that intrauterine devices are only appropriate for multiparous women has been thoroughly refuted, with studies demonstrating safe and effective use in nulliparous women and adolescents.

Intrauterine device removal is a straightforward procedure performed by grasping the strings with forceps and applying gentle, steady traction. Removal is indicated when the device reaches its expiration date, at which time a new device can be inserted in the same visit if desired. Patients experiencing intolerable side effects should be offered removal with discussion of alternative methods. Women desiring pregnancy may have the device removed at any time, with fertility returning immediately in most cases. Postmenopausal women with a levonorgestrel device should have it removed one year after the last menstrual period, and the copper device should be removed at menopause as the inflammatory mechanism is no longer needed for contraception. When strings are not visible, ultrasound confirms intrauterine location, and specialized retrieval instruments may be needed for removal.

<image>Panel A: Good IUD candidates expanded list showing nulliparous women, adolescents, immediate postpartum, immediate post-abortion, breastfeeding women, and estrogen-contraindicated patients with supporting evidence statements. Panel B: True contraindications to IUD insertion showing current pregnancy, active PID or cervicitis, unexplained vaginal bleeding, cervical or endometrial cancer, distorted uterine cavity, and Wilson disease (copper IUD only). Panel C: Myth versus evidence panels debunking PID association (Dalkon Shield historical context), ectopic pregnancy misconception (reduces all pregnancies), infertility myth (prompt return of fertility), and nulliparity restriction (safe and effective). Panel D: IUD removal indications and technique showing expiration replacement, side effect management, fertility desire, postmenopausal removal timeline, and procedure for visible versus non-visible strings.</image>

Section 7: Barrier Methods

The male condom is the most widely used barrier contraceptive method and provides the dual benefit of pregnancy prevention and sexually transmitted infection protection. Available in latex, polyurethane, and lambskin materials, latex and polyurethane condoms provide effective protection against most sexually transmitted infections including HIV, while lambskin condoms do not protect against viral pathogens due to their porous structure. Typical use effectiveness is 82 percent, with the gap between perfect and typical use largely attributable to inconsistent use rather than method failure. Condoms are widely available without a prescription, are inexpensive, and have no systemic side effects, making them an important method for patients who cannot or prefer not to use hormonal contraception. They should be used for every act of intercourse and are compatible with most other contraceptive methods as part of a dual-method strategy.

The female condom is a nitrile pouch with flexible rings at each end that is inserted into the vagina before intercourse. Typical use effectiveness is 79 percent, similar to the male condom, and it provides protection against sexually transmitted infections. The primary advantage of the female condom is that it is controlled by the receptive partner, providing an option when negotiation of male condom use is difficult. The internal ring is positioned behind the pubic bone to anchor the device, while the external ring remains outside the vaginal introitus. Female condoms can be inserted up to 8 hours before intercourse, offering greater flexibility in timing compared to the male condom.

The diaphragm and cervical cap function as physical barriers that are placed over the cervix and used in conjunction with spermicide to prevent sperm from entering the uterus. Traditional diaphragms require fitting by a healthcare provider, though a newer one-size-fits-most design has simplified access. Typical use effectiveness ranges from 71 to 86 percent depending on parity and correct use, and the device must be left in place for at least 6 hours after the last act of intercourse. The cervical cap is a smaller, thimble-shaped device that fits directly over the cervix and is held in place by suction. Both methods require user comfort with vaginal insertion and are less effective in parous women due to changes in cervical anatomy from childbirth.

Spermicide contains nonoxynol-9 as its active ingredient and is available as foam, gel, film, or suppository applied intravaginally before intercourse. Used alone, spermicide has relatively low effectiveness at approximately 72 percent typical use and is therefore recommended primarily as an adjunct to barrier methods rather than as a standalone contraceptive. A significant limitation is that nonoxynol-9 can cause vaginal irritation and disruption of the vaginal epithelium, which paradoxically may increase the risk of HIV acquisition in women with frequent use. For this reason, spermicide use is not recommended for women at high risk of HIV infection. Spermicide is most effective when combined with a condom, diaphragm, or cervical cap, and patients should be counseled that it provides no protection against sexually transmitted infections.

<image>Panel A: Male condom materials comparison showing latex (STI protective, most common), polyurethane (STI protective, latex-free), and lambskin (not STI protective, porous) with 82 percent typical use effectiveness and dual-protection benefit. Panel B: Female condom structure and insertion showing nitrile pouch with internal and external rings, positioning behind pubic bone, 79 percent typical use effectiveness, and receptive-partner controlled advantage. Panel C: Diaphragm and cervical cap comparison showing fitting requirements, placement over the cervix with spermicide, 71 to 86 percent typical use effectiveness, and 6-hour post-coital retention requirement. Panel D: Spermicide formulations (foam, gel, film, suppository) with nonoxynol-9 mechanism, 72 percent typical use effectiveness, vaginal irritation risk, increased HIV susceptibility concern, and recommendation for combination with barrier methods.</image>

Section 8: Emergency Contraception

Emergency contraception provides a critical safety net after unprotected intercourse or contraceptive failure, with three primary options differing in efficacy, timing, and access. Ulipristal acetate is the most effective oral emergency contraceptive, maintaining efficacy for up to 120 hours (5 days) after unprotected intercourse. Levonorgestrel emergency contraception is most effective within 72 hours but retains some efficacy up to 120 hours, with declining effectiveness over time. The copper intrauterine device is the most effective emergency contraceptive overall, with greater than 99 percent effectiveness when placed within 120 hours of unprotected intercourse, and offers the additional advantage of providing ongoing long-term contraception.

Levonorgestrel emergency contraception is administered as a single 1.5-milligram oral dose and is available over the counter without a prescription in the United States. Its mechanism of action is primarily through delaying or inhibiting ovulation, and it is not effective once ovulation has occurred. Efficacy may be reduced in women weighing more than 75 kilograms, and ulipristal acetate or the copper intrauterine device should be preferentially offered to these patients. Levonorgestrel emergency contraception does not disrupt an established pregnancy and is not an abortifacient. Side effects are mild and transient, including nausea, headache, and menstrual irregularity, and a repeat dose is not recommended if vomiting occurs within 3 hours, with antiemetic pretreatment considered instead.

Ulipristal acetate is a selective progesterone receptor modulator administered as a single 30-milligram oral dose that requires a prescription. Its mechanism involves delaying or inhibiting ovulation, including during the late follicular phase when levonorgestrel is no longer effective, providing a wider window of efficacy. Ulipristal maintains superior effectiveness compared to levonorgestrel particularly when used between 72 and 120 hours after unprotected intercourse and in women weighing more than 75 kilograms. An important drug interaction exists with hormonal contraception: because ulipristal blocks progesterone receptors, patients should wait at least 5 days before starting or resuming hormonal contraception to avoid reducing the emergency contraceptive effect. Barrier methods should be used in this interim period.

The copper intrauterine device functions as emergency contraception by creating a spermicidal and implantation-hostile uterine environment. With greater than 99 percent effectiveness, it is the single most effective method of emergency contraception and should be offered to all appropriate patients seeking emergency contraception. The additional benefit of the copper intrauterine device is that it transitions seamlessly into ongoing long-term contraception for up to 12 years, avoiding the need for a separate contraceptive method after the emergency event. All patients presenting for emergency contraception should be counseled about the copper intrauterine device as an option, including its superior efficacy and long-term benefits. Same-day insertion services maximize access, as barriers to follow-up visits may prevent patients from obtaining this optimal method.

<image>Panel A: Emergency contraception options comparison showing ulipristal acetate (most effective oral, up to 120 hours, prescription required), levonorgestrel (up to 72 to 120 hours, OTC), and copper IUD (most effective overall, greater than 99 percent, up to 120 hours) with efficacy timeline. Panel B: Levonorgestrel EC profile showing 1.5 mg single dose, OTC availability, ovulation delay mechanism, reduced efficacy over 75 kg, and mild transient side effects (nausea, headache). Panel C: Ulipristal acetate profile showing 30 mg single dose, prescription required, selective progesterone receptor modulator mechanism, superior late follicular efficacy, and 5-day delay before starting hormonal contraception. Panel D: Copper IUD as emergency contraception showing greater than 99 percent effectiveness, transition to 12-year long-term contraception, same-day insertion recommendation, and counseling framework for all EC-seeking patients.</image>

Section 9: Fertility Awareness and Withdrawal

Fertility awareness-based methods rely on identifying the fertile window during the menstrual cycle and either abstaining from intercourse or using barrier methods during this period. The calendar-based method estimates the fertile window based on previous cycle lengths, while the basal body temperature method detects the post-ovulatory temperature rise of approximately 0.4 degrees Fahrenheit that confirms ovulation has occurred. The cervical mucus method, also known as the Billings method, tracks changes in cervical mucus from dry and scant to wet, clear, and stretchy (spinnbarkeit) that indicate peak fertility. The symptothermal method combines temperature and cervical mucus monitoring for greater accuracy, and modern smartphone applications and wearable devices have incorporated algorithms to assist with fertility tracking.

The effectiveness of fertility awareness methods varies substantially between perfect and typical use, reflecting the significant role of user adherence and consistency. With perfect use, some methods achieve effectiveness rates of 95 to 99 percent, comparable to barrier methods. However, typical use effectiveness ranges from 76 to 88 percent, reflecting the challenges of consistent monitoring, accurate interpretation, and sustained abstinence or barrier use during the fertile window. Proper training by a qualified instructor is essential for effectiveness, as self-taught use is associated with higher failure rates. Regular menstrual cycles are important for the accuracy of calendar-based methods, and conditions that affect cycle regularity such as recent menarche, perimenopause, or breastfeeding reduce the reliability of these approaches.

Withdrawal, also known as coitus interruptus, involves male ejaculation outside the vagina and is one of the oldest known contraceptive practices. Typical use effectiveness is 78 percent, with the discrepancy from perfect use (96 percent) attributable to the difficulty of consistent and correct execution. Pre-ejaculatory fluid may contain viable sperm, particularly if there has been recent ejaculation, contributing to contraceptive failure even with perceived correct use. While withdrawal is less effective than most other contraceptive methods, it is significantly more effective than no method and should be respected as a valid choice. Clinicians should acknowledge that withdrawal is "better than nothing" and can serve as a complement to other methods or as a temporary approach while transitioning to a more effective method.

The lactational amenorrhea method is a highly effective temporary contraceptive option for postpartum women who meet three strict criteria simultaneously. The patient must have amenorrhea with no return of menses since delivery, must be exclusively or nearly exclusively breastfeeding with no supplementation, and must be less than 6 months postpartum. When all three criteria are met, the lactational amenorrhea method provides approximately 98 percent effectiveness, comparable to some hormonal methods. The mechanism involves breastfeeding-induced suppression of the hypothalamic-pituitary-ovarian axis, which inhibits ovulation. Once any criterion is no longer met, the patient should transition to another contraceptive method, and anticipatory guidance about this transition should be provided during the postpartum period to prevent unintended pregnancy.

<image>Panel A: Fertility awareness methods showing calendar-based estimation, basal body temperature charting with post-ovulatory rise, cervical mucus progression from dry to spinnbarkeit, symptothermal combination approach, and digital tracking applications. Panel B: Effectiveness comparison for fertility awareness showing perfect use (95 to 99 percent) versus typical use (76 to 88 percent) with factors affecting accuracy including training quality, cycle regularity, and adherence to abstinence or barrier use. Panel C: Withdrawal method profile showing 78 percent typical use effectiveness, pre-ejaculatory fluid concern, positioning relative to other methods, and clinical counseling approach that validates the choice while discussing more effective alternatives. Panel D: Lactational amenorrhea method criteria diagram showing three simultaneous requirements (amenorrhea, exclusive breastfeeding, less than 6 months postpartum), 98 percent effectiveness when all criteria met, and transition counseling when any criterion lapses.</image>

Section 10: Permanent Contraception

Female sterilization encompasses surgical procedures that permanently prevent pregnancy by interrupting the fallopian tubes. Bilateral salpingectomy, the complete removal of both fallopian tubes, has become the preferred method based on evidence that it reduces the risk of high-grade serous ovarian cancer, which is now believed to originate from the fimbriated end of the fallopian tube. Traditional tubal ligation methods include application of clips, rings, or cauterization to occlude the tubes and remain acceptable options. Sterilization may be performed as an interval procedure at any time in the cycle or in the immediate postpartum period, typically during cesarean delivery or within 48 hours of vaginal delivery. Efficacy exceeds 99 percent, and the ovarian cancer risk reduction associated with salpingectomy provides a compelling rationale for this approach.

Counseling before permanent sterilization is an ethical obligation that must address the permanent nature of the decision and alternative options. Patients should understand that sterilization is intended to be irreversible and that reversal attempts have variable success and significant cost. Regret is more common among women who are younger at the time of sterilization, who are nulliparous, or who undergo the procedure during a period of relationship stress or concurrent with another major life event. Long-acting reversible contraception provides comparable contraceptive effectiveness and should be presented as an alternative that preserves future reproductive options. Although sterilization failure is rare, when it does occur, there is an increased proportion of ectopic pregnancies, and patients should be informed of this risk.

Male sterilization through vasectomy is an outpatient procedure performed under local anesthesia that interrupts the vas deferens to prevent sperm from reaching the ejaculate. Vasectomy is simpler, safer, and less expensive than female sterilization, yet it is performed far less frequently, highlighting an opportunity for improved counseling about male contraceptive options. Efficacy exceeds 99 percent after confirmation of azoospermia, which requires a follow-up semen analysis at 8 to 16 weeks post-procedure. The patient must use an alternative contraceptive method until azoospermia is confirmed, as residual sperm may persist in the reproductive tract for several months. Complications are uncommon and include hematoma, infection, and chronic post-vasectomy pain syndrome.

Sterilization reversal is possible for both female and male procedures but has variable success and significant limitations. Tubal anastomosis, the surgical reconnection of previously ligated tubes, has success rates that depend on the length of remaining tube, the method of original sterilization, and the patient's age. Vasectomy reversal (vasovasostomy or vasoepididymostomy) generally has better success rates than tubal reversal, particularly when performed within 10 years of the vasectomy. In vitro fertilization represents an alternative to surgical reversal for both female and male sterilization and may be more cost-effective depending on the clinical circumstances. The possibility of reversal should not be presented as a reason to proceed with sterilization, as the procedure should be approached as permanent, and patients should be thoroughly counseled before rather than after the decision is made.

<image>Panel A: Female sterilization methods showing bilateral salpingectomy (preferred, ovarian cancer risk reduction) versus tubal ligation (clips, rings, cautery) with interval and postpartum timing options and greater than 99 percent efficacy. Panel B: Sterilization counseling framework addressing permanence discussion, regret risk factors (young age, nulliparity, relationship stress), LARC alternatives, and ectopic pregnancy risk if failure occurs. Panel C: Vasectomy procedure overview showing outpatient local anesthesia approach, vas deferens interruption, semen analysis confirmation at 8 to 16 weeks, simpler and safer profile compared to female sterilization, and complication rates. Panel D: Reversal options comparison showing tubal anastomosis success factors (tube length, method, age), vasectomy reversal success rates (better within 10 years), IVF as alternative pathway, and counseling principle that reversal possibility should not drive the sterilization decision.</image>

Summary

• LARC methods (implant, IUDs) are the most effective reversible contraceptives with user-independent efficacy exceeding 99 percent and are recommended as first-line options
• Combined hormonal contraception (OCP, patch, ring) is contraindicated in patients with VTE history, migraine with aura, and smoking 15 or more cigarettes daily at age 35 or older
• US MEC Category 4 represents absolute contraindication with unacceptable health risk, while Category 3 indicates risks usually outweigh benefits
• Progestin-only methods are safe for patients with estrogen contraindications including breastfeeding, VTE history, and migraine with aura
• The copper IUD provides 10 to 12 years of non-hormonal contraception with heavier periods as the main side effect
• Hormonal IUDs produce lighter periods or amenorrhea and are available in 3 to 7 year durations depending on the formulation
• IUD myths have been debunked: they are safe for nulliparous women, do not cause PID or infertility, and reduce rather than increase ectopic pregnancy risk
• Emergency contraception options include the copper IUD (most effective overall), ulipristal acetate (most effective oral), and levonorgestrel (available OTC)
• Fertility awareness methods require training and consistent practice, achieving 76 to 88 percent typical use effectiveness
• Bilateral salpingectomy is the preferred female sterilization method due to ovarian cancer risk reduction, while vasectomy is simpler and safer than female sterilization

Key Terms

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