Post-Graduate Programme in Epidemiology, Universidade Federal de Pelotas, Pelotas, Brazil.
PLoS One. 2013 Aug 20;8(8):e71548. doi: 10.1371/journal.pone.0071548. eCollection 2013.
Performance in intelligence tests tends to be higher among individuals breastfed as infants, but little is known about the association between breastfeeding and achieved schooling. We assessed the association of infant feeding with school achievement in five cohorts from low- and middle-income countries. Unlike high-income country settings where most previous studies come from, breastfeeding is not positively associated with socioeconomic position in our cohorts, thus reducing the likelihood of a spurious positive association.
Participants included 10,082 young adults from five birth cohorts (Brazil, India, Guatemala, the Philippines, and South Africa). The exposures variables were whether the subject was ever breastfed, total duration of breastfeeding, and age at introduction of complementary foods. We adjusted the estimates for age at follow up, sex, maternal age, smoking during pregnancy, birthweight and socioeconomic position at birth. The key outcome was the highest grade achieved at school. In unadjusted analyses, the association between ever breastfeeding and schooling was positive in Brazil, inverse in the Philippines, and null in South Africa; in adjusted analyses, these associations were attenuated. In Brazil, schooling was highest among individuals breastfed for 3-12 months whereas in the Philippines duration of breastfeeding was inversely associated with schooling; and null associations were observed in South Africa and Guatemala. These associations were attenuated in adjusted models. Late introduction of solid foods was associated with lower schooling achievement in Brazil and South Africa.
Measures of breastfeeding are not consistently related to schooling achievement in contemporary cohorts of young adults in lower and middle-income countries.
在婴幼儿时期接受母乳喂养的个体在智力测试中的表现往往更高，但人们对母乳喂养与所接受的学校教育之间的关系知之甚少。我们评估了来自低收入和中等收入国家的五个队列中婴儿喂养与学校成绩的关系。与大多数先前研究来自的高收入国家环境不同，在我们的队列中，母乳喂养与社会经济地位没有正相关关系，因此降低了虚假正相关关系的可能性。
参与者包括来自五个队列的 10082 名年轻人（巴西、印度、危地马拉、菲律宾和南非）。暴露变量是受试者是否曾接受母乳喂养、母乳喂养总持续时间以及引入补充食品的年龄。我们调整了随访年龄、性别、母亲年龄、孕期吸烟、出生体重和出生时社会经济地位的估计值。主要结果是在校获得的最高年级。在未调整的分析中，巴西的母乳喂养与教育之间存在正相关关系，菲律宾呈负相关，南非则呈中性；在调整后的分析中，这些关联减弱了。在巴西，接受母乳喂养 3-12 个月的个体的教育程度最高，而在菲律宾，母乳喂养的持续时间与教育程度呈负相关；在南非和危地马拉则观察到中性关联。这些关联在调整后的模型中减弱了。在巴西和南非，固体食物的引入时间较晚与较低的学业成绩有关。
在低收入和中等收入国家的当代年轻人队列中，母乳喂养的措施与学校教育成就并不一致。
