Mishell D R
Department of Obstetrics and Gynecology, University of Southern California, School of Medicine, Los Angeles, USA.
J Reprod Med. 1996 May;41(5 Suppl):381-90.
Depot medroxyprogesterone acetate (DMPA) is an aqueous suspension of 17-acetoxy 6-methyl progestin administered by intramuscular injection for long-term contraception. This highly effective injectable formulation of medroxyprogesterone acetate (MPA) has a prolonged duration of action since the progestin is released slowly from the muscle. MPA is detected in the serum within 30 minutes after an injection of 150 mg. Serum concentrations vary between individual women but generally plateau at about 1.0 ng/mL for about three months, after which there is a gradual decline. In some women, MPA can be detected in the serum for as long as nine months after a single injection of 150 mg. The circulating MPA initially inhibits the midcycle leutinizing hormone (LH) peak, but LH and follicle stimulating hormone (FSH) levels remain in the range of those for the luteal phase of a pretreatment control cycle. Since ovulation is inhibited, serum progesterone levels remain low (< 0.4 ng/mL) for several months following an injection of DMPA. When MPA levels fall below 0.1 ng/mL, ovulation resumes. Thus, return to fertility is delayed for several months if a woman wishes to conceive after receiving one or more injections of DMPA. Following an injection of DMPA, serum estradiol levels initially are in the early to midfollicular phase range (mean approximately 50 pg/nL). Serum estradiol levels begin to rise about four months after a single injection when MPA levels fall below 0.5 ng/mL. For women who have used DMPA for several years, serum estradiol levels range between 10 and 92 pg/mL, with mean levels of about 40 pg/mL. Despite these low levels of estradiol, hot flushes are a rare event, and the vaginal epithelium remains moist and well rugated. Women using DMPA for several years do not observe a change in breast size. DMPA causes the endometrium to become atrophic, with small, straight endometrial glands and decidualized stroma. The cervical mucus remains thick and viscid. DMPA is a very effective form of contraception because of its multiple mechanisms of action and slow release into the circulation.
醋酸甲羟孕酮长效注射剂（DMPA）是一种17 - 乙酰氧基6 - 甲基孕激素的水混悬液，通过肌肉注射用于长期避孕。这种高效的醋酸甲羟孕酮（MPA）注射剂作用持续时间延长，因为孕激素从肌肉中缓慢释放。注射150毫克后30分钟内血清中可检测到MPA。个体女性的血清浓度有所不同，但一般在约1.0纳克/毫升的水平保持平稳约三个月，之后逐渐下降。在一些女性中，单次注射150毫克后，血清中MPA可持续检测长达九个月。循环中的MPA最初抑制月经周期中期促黄体生成素（LH）峰值，但LH和卵泡刺激素（FSH）水平仍处于预处理对照周期黄体期的范围内。由于排卵受到抑制，注射DMPA后数月内血清孕酮水平保持较低（<0.4纳克/毫升）。当MPA水平降至低于0.1纳克/毫升时，排卵恢复。因此，如果女性在接受一次或多次DMPA注射后希望怀孕，生育能力的恢复会延迟数月。注射DMPA后，血清雌二醇水平最初处于卵泡早期至中期范围（平均约50皮克/纳升）。单次注射后约四个月，当MPA水平降至低于0.5纳克/毫升时，血清雌二醇水平开始上升。对于使用DMPA数年的女性，血清雌二醇水平在10至92皮克/毫升之间，平均水平约为40皮克/毫升。尽管雌二醇水平较低，但潮热很少发生，阴道上皮保持湿润且有良好的皱襞。使用DMPA数年的女性未观察到乳房大小的变化。DMPA使子宫内膜萎缩，子宫内膜腺体小而直，基质蜕膜化。宫颈黏液保持浓稠。由于其多种作用机制以及向循环系统的缓慢释放，DMPA是一种非常有效的避孕方式。
