Gold M A
University of Pittsburgh School of Medicine, Pa., USA.
Adv Pediatr. 2000;47:309-34.
High rates of adolescent pregnancy remain a challenge for health care providers. For most sexually active adolescents, pregnancy is unintended. Emergency contraception, also called the "morning-after-pill" or postcoital contraception, is a way to prevent pregnancy after unprotected intercourse. In the United States, three forms of emergency contraception currently are available: high-dose combination estrogen and progestin pills, high-dose progestin-only pills, and postcoital insertion of a copper intrauterine device. The postcoital intrauterine device is used infrequently. When emergency contraceptive pills (ECPs) are taken within 72 hours of unprotected intercourse, they reduce the risk of pregnancy by at least 75%. However, they are most effective if taken within 24 hours of coitus. Eleven brands of pills currently are marketed in the United States that conform to the regimens approved by the Food and Drug Administration (FDA) for this indication. Recently, two prepackaged ECPs were approved by the FDA. The only medical contraindication to prescribing ECPs is pregnancy. The most common side effects are nausea and vomiting, followed by menstrual disturbances, breast tenderness, abdominal cramping, dizziness, headache, and mood changes. Because vomiting can compromise the efficacy of ECPs, routine pretreatment with an antiemetic is recommended. Primary care providers can reduce unintended adolescent pregnancy by routinely counseling adolescents at all office visits about the existence of emergency contraception and by prescribing it in advance and over the telephone.
青少年怀孕率居高不下，这对医疗服务提供者来说仍是一项挑战。对于大多数有性行为的青少年而言，怀孕往往是意外情况。紧急避孕，也被称为“事后避孕药”或性交后避孕，是一种在无保护性交后预防怀孕的方法。在美国，目前有三种形式的紧急避孕措施：高剂量复方雌激素和孕激素药片、仅含高剂量孕激素的药片，以及性交后插入含铜宫内节育器。含铜宫内节育器在性交后较少使用。如果在无保护性交后72小时内服用紧急避孕药（ECP），可将怀孕风险降低至少75%。然而，在性交后24小时内服用最为有效。目前在美国市场上销售的有11个品牌的药片符合美国食品药品监督管理局（FDA）批准用于此适应症的用药方案。最近，两种预包装的紧急避孕药获得了FDA的批准。开具紧急避孕药唯一的医学禁忌是怀孕。最常见的副作用是恶心和呕吐，其次是月经紊乱、乳房胀痛、腹部绞痛、头晕、头痛和情绪变化。由于呕吐会影响紧急避孕药的疗效，建议常规使用止吐药进行预处理。初级保健提供者可以通过在每次门诊就诊时常规向青少年咨询紧急避孕措施的存在情况，并提前和通过电话开出处方，来减少青少年意外怀孕的情况。
