毒理性
◉ 母乳喂养期间使用总结：这份记录包含了关于单独使用口服炔诺孕酮作为避孕方法的具体信息。对复方口服避孕药有兴趣的人应咨询题为《避孕药，口服，复方》的记录。目前没有关于在哺乳期间使用高剂量炔诺孕酮醋酸酯的信息。
尽管在哺乳期间首选非激素方法，但像炔诺孕酮这样的仅含孕激素的避孕药被视为哺乳期选择的激素避孕药。质量较好的证据表明，炔诺孕酮不会对乳汁的成分、婴儿的生长发育或乳汁供应产生不利影响。一些证据表明，仅含孕激素的避孕药可能有助于预防哺乳期间的骨密度流失，或者至少不会加剧这种情况。计划哺乳的妇女中有很大一部分在产后3个月停止使用口服仅含孕激素的避孕药，而仅含孕激素的避孕药通常会导致快速再次怀孕。
◉ 对哺乳婴儿的影响：在使用炔诺孕酮庚酸酯（Norplant）的母亲所生的婴儿中没有发现一致的身体、精神或放射学差异。一些研究发现，接受治疗的妇女的婴儿体重增长增加。
一项对12名产后48小时开始每天口服炔诺孕酮350微克的妇女进行的短期研究发现，与8名服用安慰剂的妇女相比，在14天内婴儿体重增长没有差异。
◉ 对哺乳和母乳的影响：不同规模和质量的研究发现，使用长效炔诺孕酮注射剂（醋酸酯或庚酸酯）对母乳的质量没有重要的负面影响，对乳汁供应和哺乳期的持续时间没有影响或有所增加。在一项研究中，产后6天接受植入物的妇女在植入后2周出现了短暂的乳汁蛋白下降。在这组妇女中，在植入后2到4个月之间也观察到了乳汁磷含量的下降，并且在植入后3个月，早期植入组的补充率更高。在另一项研究中，产后不到48小时接受炔诺孕酮庚酸酯长效注射剂的妇女在产后6周患产后抑郁症的可能性是正常妇女的2.5到3倍。在产后1周和12周没有发现差异。
一项对12名产后48小时开始每天口服炔诺孕酮350微克的妇女进行的短期研究发现，与8名服用安慰剂的妇女相比，在14天内乳汁产量或乳汁成分没有差异。
一项小型、非随机研究发现，与接受非激素避孕的对照组相比，每天口服炔诺孕酮350微克会减少乳汁的数量和质量（蛋白质、脂质和钙含量较低）。
在一项非随机、非盲的研究中，比较了出院时正在哺乳的妇女，102名产后妇女在早期产后期间接受了醋酸甲羟孕酮长效注射剂（剂量未说明，平均产后51.9小时；范围6.25至132小时），181名妇女接受了另一种仅含孕激素的避孕药，而138名妇女使用了非激素避孕药。在2周和6周时没有发现哺乳率的差异，但在4周时使用任何激素避孕药的妇女哺乳率较低（72.1%对77.6%）。作者结论是，在早期产后期间开始的仅含孕激素避孕药对哺乳率没有不利影响。
一项分析了一项前瞻性队列研究的数据，该研究追踪了2005年5月至2007年6月期间美国的妇女，从第三孕期一直追踪到产后第一年。分析了打算在第三孕期哺乳至少3个月并在产后3个月使用避孕药的妇女的子集（n = 1349）。打算至少哺乳4个月并服用炔诺孕酮等仅含孕激素的口服避孕药的妇女在4个月时哺乳（独占或非独占）的可能性是有使用非激素避孕药妇女的3.15倍。表示会哺乳3到4个月的妇女的4个月哺乳率与使用非激素避孕药的妇女相当。这些比率远高于使用含雌激素的复方口服避孕药的妇女。
◉ Summary of Use during Lactation:This record contains information specific to oral norethindrone used alone for contraception. Those with an interest in a combination oral contraceptive should consult the record entitled, Contraceptives, Oral, Combined. No information is available on the use of high-dose norethindrone acetate during breastfeeding.
Although nonhormonal methods are preferred during breastfeeding, progestin-only contraceptives such as norethindrone are considered the hormonal contraceptives of choice during lactation. Fair quality evidence indicates that norethindrone does not adversely affect the composition of milk, the growth and development of the infant or the milk supply. Some evidence indicates that progestin-only contraceptives may offer protection against bone mineral density loss during lactation, or at least do not exacerbate it. A large percentage of women who planned to breastfeed discontinued oral progestin-only contraceptives by 3 months postpartum and progestin-only contraceptives often result in rapid repeat pregnancy.
◉ Effects in Breastfed Infants:No consistent physical, mental, or radiologic differences have been found in infants whose mothers were using norethindrone enanthate (Norplant). Some studies found increased infant weight gain among the infants of treated women.
A short-term study of 12 women who received oral norethindrone 350 mcg daily starting 48 hours postpartum found no differences in infant weight gain over 14 days compared to 8 women taking a placebo.
◉ Effects on Lactation and Breastmilk:Studies of varying size and quality on the use of long-acting norethindrone injections (acetate or enanthate) have found that the use of levonorgestrel implants (Norplant or Norplant-2) as a contraceptive beginning at 6 weeks postpartum or later either has no clinically important negative effect on the quality of breastmilk and results in either no effect or an increase in the milk supply and duration of lactation. In one study, women who received the implant at 6 days postpartum, a transient decrease in milk protein occurred 2 weeks after implant insertion. A decrease in milk phosphorus content was also observed between 2 and 4 months after implant insertion in this group and at 3 months postpartum, the early insertion group had a higher rate of supplementation. In another study, women given norethindrone enanthate depot injection less than 48 hours postpartum were 2.5 to 3 times more likely to have postpartum depression at 6 weeks postpartum. No differences were seen at 1 and 12 weeks postpartum.
A short-term study of 12 women who received oral norethindrone 350 mcg daily starting 48 hours postpartum found no differences in milk production or milk composition over 14 days compared to 8 women taking a placebo.
One small, nonrandomized study found that oral norethindrone 350 mcg daily decreased the quantity and quality (lower protein, lipids and calcium) compared to controls who received nonhormonal contraception.
In a nonrandomized, nonblinded study comparing women who were breastfeeding at discharge, 102 postpartum women received depot medroxyprogesterone acetate (dosage not stated) in the early postpartum period (average 51.9 hours postpartum; range 6.25 to 132 hours), 181 received another progestin-only contraceptive and 138 used nonhormonal contraception. No differences in breastfeeding rates were seen at 2 and 6 weeks, but women receiving any hormonal contraceptive were breastfeeding at a lower rate (72.1% vs 77.6%) at 4 weeks postpartum. The authors concluded that progestin-only contraception initiated in the early postpartum period had no adverse effects on breastfeeding rates.
A study analyzed data from a prospective cohort study of U.S. women from May 2005 through June 2007. Women were followed from the third trimester of pregnancy throughout the first year postpartum. Data from the subset of women who intended to breastfeed for 3 months or longer postpartum during their third trimester of pregnancy and who were using a contraceptive at 3 months postpartum were analyzed (n = 1349). Women who intended to breastfeed for at least 4 months and were taking a progestin-only oral contraceptive, such as norethindrone, were 3.15 times more likely to be breastfeeding (exclusive or nonexclusive) at 4 months than women who used a nonhormonal contraceptive. Women who said they would breastfeed for 3 to 4 months had 4-month breastfeeding rates equivalent to those using a nonhormonal contraceptive. These rates were much higher than those of women who were taking an estrogen-containing, combined oral contraceptive.
来源:Drugs and Lactation Database (LactMed)
