Rosenberg M
J Biosoc Sci. 1989 Jul;21(3):335-48.
Using medical records from maternity clinics in the two Norwegian cities Oslo and Bergen, the effect of lactation on infant mortality during the period 1860-1930 is examined, comparing those who were and were not breast-fed in a total of about 6900 live born infants. The mortality of children not breast-fed was nearly three times that of those who were breast-fed. In a Cox regression analysis the infant's year of birth and the mother's marital status were found to influence mortality in addition to lactation. Children born to unmarried mothers experienced a mortality about twice that of those born to married mothers, both during on-going lactation and in the absence of lactation, up to about 1915. Children born in Oslo had a slightly higher mortality than those born in Bergen. The duration of lactation was found to have a continuing protective effect on infant survival after weaning--the longer the duration, the lower the mortality after cessation of lactation.
利用挪威奥斯陆和卑尔根这两座城市产科诊所的医疗记录，研究了1860年至1930年期间哺乳对婴儿死亡率的影响，对总共约6900名活产婴儿中母乳喂养和非母乳喂养的婴儿进行了比较。非母乳喂养儿童的死亡率几乎是母乳喂养儿童的三倍。在Cox回归分析中，发现除了哺乳外，婴儿的出生年份和母亲的婚姻状况也会影响死亡率。未婚母亲所生子女的死亡率在哺乳期间和不哺乳时（直至约1915年）约为已婚母亲所生子女的两倍。在奥斯陆出生的儿童死亡率略高于在卑尔根出生的儿童。研究发现，哺乳期的长短对断奶后婴儿的存活有持续的保护作用——哺乳期越长，停止哺乳后的死亡率越低。
