Emergency contraception can be used after intercourse to prevent a pregnancy from occurring, most commonly by altering ovulation or preventing ovum fertilization. Primary forms of emergency contraception include levonorgestrel, ulipristal, and the copper intrauterine device.
Patients with recent unprotected sexual intercourse or contraception failure (eg, broken condom) are at risk for unintended pregnancy and may be candidates for emergency contraception
Pregnancy status determines eligibility for EC use:
<aside> 💡 Most states allow adolescents to receive confidential care for contraception, pregnancy, and sexually transmitted diseases without parental consent
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| Method | Timing after intercourse | Efficacy | Contraindications |
|---|---|---|---|
| Copper-containing intrauterine device | 0-120 hr | >99% | • Wilson disease |
| • Active pelvic infection | |||
| • Severe uterine cavity distortion | |||
| Progestin-releasing intrauterine device | 0-120 hr | >99% | • Breast cancer |
| • Active pelvic infection | |||
| • Severe uterine cavity distortion | |||
| Ulipristal | 0-120 hr | 98%-99% | • None |
| Oral levonorgestrel (ie, Plan B) | 0-72 hr | 92%-98% | • None |
| **Oral contraceptives (**COCs containing levonorgestrel or norgestrel) | 0-72 hr | 75%-89% | • None |
In addition to being the most effective method of emergency method of contraception an IUD can be left in place to provide continued contraception.
Levonorgestrel and ulipristal pills are EC methods that prevent pregnancy primarily by delaying ovulation ( same moa of COCs use in emergency contraception) . Although these medications are more accessible than an IUD, which requires a provider trained in its insertion, they are slightly less effective at pregnancy prevention than an IUD and do not offer the benefit of continued contraception.
Levonorgestrel prevents ovulation and can be taken up to 72 hours after intercourse, although it is less effective at preventing pregnancy than the other methods. It has no significant contraindications and is safe to use in breastfeeding women, . Adverse effects include nausea, irregular menstrual bleeding, lower abdominal pain, and fatigue. Ulipristal is an anti-progesterone that also prevents ovulation. It can be used up to 5 days after intercourse and has no significant contraindications. Adverse effects are like those for levonorgestrel.
A copper intrauterine device is the most effective form of emergency contraception and its use can be continued for long term contraception. It is effective if placed within 5 days of intercourse and has few contraindications, with exceptions including active uterine infection or an underlying anatomic abnormality (eg, septate uterus). Adverse effects include abdominal cramping, vaginal bleeding, infection, and uterine perforation
The levonorgestrel pill (ie, Plan B) is the most readily available form of EC; the high dose of progestin in these pills prevents pregnancy by inhibiting the LH surge, thereby delaying ovulation. Additional mechanisms include cervical mucus thickening and thinning of the endometrial lining. Levonorgestrel pills are highly effective (ie, up to 94%); however, effectiveness decreases over the course of 72 hours (ie, as low as 59%). Therefore, levonorgestrel pills should be provided as soon as possible after unprotected intercourse.
ulipristal pill, a progestin receptor blocker that prevents pregnancy by delaying ovulation and impairing implantation. Ulipristal can be taken up to 120 hours after unprotected intercourse; however, it should be administered as soon as possible because its effectiveness decreases with time.
Choice A) Combination oral contraceptives, commonly used for precoital contraception, may also be used for EC by taking multiple pills simultaneously to achieve the progestin level required to delay ovulation. However, the high estrogen content typically causes intolerable side effects (eg, severe nausea), and this method is less effective (ie, 47%-89%) than ulipristal & levonorgestrel pills..
(Choices C and E) A progestin-releasing subdermal implant is a long-acting, reversible contraceptive used for precoital contraception. Because it provides sustained release of low-dose progestin, it cannot achieve the acute increase in progestin levels required to delay ovulation for EC. Similarly, the transdermal estrogen-progestin patch is a slow-releasing combined hormonal contraceptive used only for precoital contraception.