Department of Obstetrics and Gynecology, School of Medical Sciences, University of Campinas, Campinas, Brazil.
Osteoporos Int. 2012 Jun;23(6):1691-8. doi: 10.1007/s00198-011-1767-y. Epub 2011 Sep 1.
Prospective cohort study performed to evaluate bone mineral density (BMD) changes up to 12 months postpartum of healthy women and its association with breastfeeding, contraceptive methods, amenorrhea, and body mass index (BMI). There is a trend in bone loss during the first 6 months with posterior recovery, with evidence of a protective effect of hormonal contraception.
This study was conducted to evaluate bone mineral density (BMD) changes during postpartum period among healthy women and its association with breastfeeding, use of contraceptive methods, amenorrhea and body mass index (BMI).
A prospective cohort study including 100 healthy women. Distal BMD was measured 7-10 days, 3, 6, and 12 months postpartum at the nondominant forearm using dual-energy X-ray absorptiometry. Data about breastfeeding duration, amenorrhea, contraceptive use and BMI were collected.
Seventy-eight women had a complete set of BMD measurements. The mean duration of exclusive breastfeeding was 125.9 (±66.6) days, with a median total lactation period of 263.5 days. The mean duration of amenorrhea was 164.2 (±119.2) days. BMD measurements showed a significant decrease in the distal radius, however with no significance in the ultradistal radius. When considering only the nonhormonal contraceptive users, the difference at 12 months was significant. Multivariate analysis of variance showed that both BMI and contraceptive use were significantly correlated with BMD. Multiple linear regression analysis showed significant correlation of distal radius with baseline BMD at the same site, pregestational BMI, age, years of schooling and difference in BMI. For ultradistal radius, there was a significant direct correlation with its baseline BMD and pregestational BMI.
There was a trend in bone loss during the first 6 months postpartum with posterior recovery. Also, hormonal contraceptive methods provided protection of bone loss. However, the long duration of breastfeeding and the follow-up were not sufficient to draw definitive conclusions on postweaning BMD conditions.
评估健康女性产后 12 个月内骨密度（BMD）的变化及其与母乳喂养、避孕方法、闭经和体重指数（BMI）的关系。研究结果显示，产后前 6 个月存在骨量丢失趋势，而后逐渐恢复，且激素避孕方法具有一定的保护作用。
这是一项前瞻性队列研究，共纳入 100 名健康女性。采用双能 X 射线吸收法在非优势前臂测量产后 7-10 天、3 个月、6 个月和 12 个月时的远端 BMD。收集母乳喂养持续时间、闭经、避孕方法和 BMI 等数据。
78 名女性完成了完整的 BMD 测量。纯母乳喂养持续时间中位数为 263.5 天，平均为 125.9（±66.6）天；闭经时间中位数为 164.2（±119.2）天。远端桡骨的 BMD 测量值明显下降，但在超远端桡骨中无显著差异。仅考虑非激素避孕方法使用者时，12 个月时的差异具有统计学意义。方差分析显示，BMI 和避孕方法与 BMD 显著相关。多元线性回归分析显示，远端桡骨与同一部位的基础 BMD、妊娠前 BMI、年龄、受教育年限和 BMI 差异显著相关。对于超远端桡骨，与基础 BMD 和妊娠前 BMI 存在显著的直接相关性。
产后前 6 个月存在骨量丢失趋势，而后逐渐恢复。此外，激素避孕方法可防止骨量丢失。但是，母乳喂养时间长且随访时间不够长，无法对断乳后 BMD 状况得出明确结论。
