Campbell O M, Gray R H
Department of Population Dynamics, Johns Hopkins School of Hygiene and Public Health.
Am J Obstet Gynecol. 1993 Jul;169(1):55-60. doi: 10.1016/0002-9378(93)90131-2.
Our aim was to characterize the influence of breast-feeding on the postpartum return of ovarian activity for the purpose of assessing the relevance of the lactational amenorrhea method of contraception for women in the United States.
Twenty-two non-breast-feeding and 60 breast-feeding women from Baltimore collected daily urine specimens that were assayed to determine ovulation and luteal phase adequacy. Vaginal bleeding was ascertained weekly, and breast-feeding women recorded infant feeding daily. Proportion-hazards models were used to relate measures of breast-feeding to the occurrence of ovulation.
Two thirds of women ovulated before their first vaginal bleeding, but 47% of those cycles had decreased luteal-phase pregnanediol excretion. Breast-feeding frequency and suckling duration were significant predictors of the risk of ovulation (p < 0.001). Supplementation with bottle feeding was associated with a reduction in breast-feeding.
A high degree of protection from pregnancy can be achieved using breast-feeding frequency and suckling duration, even with supplemented breast-feeding.
我们的目的是描述母乳喂养对产后卵巢活动恢复的影响，以便评估哺乳期闭经避孕法在美国女性中的相关性。
来自巴尔的摩的22名非母乳喂养女性和60名母乳喂养女性每天收集尿液样本，检测以确定排卵和黄体期是否充足。每周确定阴道出血情况，母乳喂养女性每天记录婴儿喂养情况。比例风险模型用于将母乳喂养措施与排卵发生情况相关联。
三分之二的女性在首次阴道出血前排卵，但这些周期中有47%的黄体期孕二醇排泄减少。母乳喂养频率和哺乳时间是排卵风险的重要预测因素（p<0.001）。添加奶瓶喂养与母乳喂养减少有关。
即使是添加了奶瓶喂养的情况，通过母乳喂养频率和哺乳时间也能实现高度的避孕效果。
