Smith D P
Stud Fam Plann. 1985 May-Jun;16(3):154-63.
Numerous studies have demonstrated a strong correlation between breastfeeding and the duration of amenorrhea and between breastfeeding and the birth interval at the individual level. In the present study, both these correlations are shown to hold at the national level, in developing countries. In countries where the median durations of breastfeeding are relatively long or the rates of contraceptive use are relatively high, median birth intervals are longer than in countries where the median breastfeeding durations are shorter and contraceptive use is less widespread. In countries where fertility is moderate or high, however, the incidence of very short birth intervals is higher when median breastfeeding durations are relatively short. The findings suggest that contraception as it is presently practiced is an inadequate substitute for breastfeeding.
众多研究已在个体层面证实了母乳喂养与闭经持续时间以及母乳喂养与生育间隔之间存在紧密关联。在本研究中，这两种关联在发展中国家的国家层面也得到了证实。在母乳喂养中位数持续时间相对较长或避孕使用率相对较高的国家，生育间隔中位数比母乳喂养中位数持续时间较短且避孕使用不太普遍的国家更长。然而，在生育率处于中等或较高水平的国家，当母乳喂养中位数持续时间相对较短时，极短生育间隔的发生率更高。研究结果表明，目前所采用的避孕方法并不能充分替代母乳喂养。
