One post-partum behaviour that may be protective against post-partum weight retention and long-term weight gain among women of reproductive age is lactation because of its potential role in resetting maternal metabolism after pregnancy. However, most of the evidence focuses on weight retention at 6, 12, or 24 months post-partum, and data beyond 2 years after birth are sparse, and findings are inconclusive. Therefore, our aim was to assess the association of parity and mean duration of lactation per child with long-term weight change in Mexican women. We assessed the association of parity and mean duration of lactation per child with long-term weight change in 75,421 women from the Mexican Teachers' Cohort. Several multivariable regression models were fit to assess these associations. We also examined the non-linear association between duration of lactation and weight change using restricted cubic splines. We found that parous women (≥4 children) gained 2.81 kg more (95% CI [2.52, 3.10]) than did nulliparous women. The association between mean duration of lactation per child and weight change appeared to be non-linear. Women who breastfed on average 3-6 months per child had lower gain weight (-1.10, 95% CI [-1.58, -0.47 kg]) than had women who did not breastfeed. This association was linear up to 6 months of lactation per child. Our findings suggest that parity alters weight-gain trajectory in women and that lactation could reduce this alteration. These findings are important in the prevention of excessive weight gain through reproductive years and their future health implications.

中文翻译：

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墨西哥妇女的平价，哺乳期和长期体重变化。

哺乳期的一种产后行为可能会阻止产后体重的保持和长期增重，这是哺乳期，因为它可能在怀孕后恢复母亲的新陈代谢中发挥作用。但是，大多数证据都集中在产后6、12或24个月的体重保持，而出生后2年以上的数据稀疏，并且结论尚无定论。因此，我们的目的是评估墨西哥妇女的平均胎龄与每个孩子平均泌乳时间与长期体重变化之间的关系。我们评估了墨西哥教师队列中75,421名妇女的平均胎龄和每个孩子的平均泌乳时间与长期体重变化之间的关系。几种多元回归模型适合评估这些关联。我们还使用限制的三次样条检查了哺乳期与体重变化之间的非线性关系。我们发现，同胎妇女（≥4个孩子）比未产妇增加了2.81千克（95％CI [2.52，3.10]）。每个孩子平均泌乳时间与体重变化之间的关系似乎是非线性的。与没有母乳喂养的妇女相比，每个孩子平均母乳喂养3-6个月的妇女体重增加（-1.10，95％CI [-1.58，-0.47千克]）低。每个孩子的哺乳期最多六个月呈线性关系。我们的发现表明，胎次可以改变女性的体重增加轨迹，而泌乳可以减少这种变化。这些发现对预防生育年体重增加过多及其对未来健康的影响非常重要。