During the breastfeeding period, important transient changes in calcium homeostasis are verified in the maternal skeleton, to meet the demand for calcium for breastmilk production. The literature is inconclusive regarding the causes and percentages of involvement of bone densitometry resulting from exclusive breastfeeding (4 to 6 months). This article aims to systematically review the literature, to determine the occurrence, intensity, and factors involved in alterations in maternal bone mineral density (BMD), during a period of 4 to 6 months of exclusive breastfeeding. The search descriptors “woman”, “breastfeeding”, “human milk”, and “bone mineral density” were used in the electronic databases of the Virtual Health Library, Scielo (Scientific Electronic Library Online), CAPES Periodicals Portal, LILACS, Embase, PubMed/Medline, Cochrane, Scopus, and Web of Science in June 2023. Inclusion criteria for breastfeedingmothers were; aged to 40 years, primigravida, exclusively breastfeeding, with BMD assessments using dual-energy X-ray absorptiometry (DXA), with values expressed at baseline and from 4 to 6 months postpartum. The Jadad scale, Newcastle–Ottawa Scale, and Oxford Centre for Evidence-based Medicine – levels of evidence were adopted to assess the quality of the studies. For the meta-analytical study, statistical calculations were performed. Initially, 381 articles were found using the search strategy and 26 were read in full. After risk of bias analysis, 16 articles remained in the systematic review and four were included in the meta-analysis. The studies showed a reduction in bone mass in the lumbar spine in the first months postpartum (4 – 6 months), when compared with a longer period of breastfeeding (12–18 months). The breastfeeding group presented a greater impact in the meta-analysis than the control group (non-breastfeeding, pregnant, or immediate postpartum), with a reduction in BMD in the lumbar spine of -0.18 g/cm2 (-0.36, -0.01 g/cm2); 95% Confidence Interval, on a scale from 0 to 10. Our results demonstrated a transitory reduction in bone densitometry of the lumbar spine during exclusive breastfeeding for 4 to 6 months, which was gradually restored later in the postpartum period. More prospective studies are needed to better understand the topic. PROSPERO platform (nº CRD42021279199), November 12th, 2021.

中文翻译：

---

母乳喂养 4 至 6 个月女性腰椎骨矿物质密度：系统评价和荟萃分析

在母乳喂养期间，母体骨骼中钙稳态的重要瞬时变化得到证实，以满足母乳生产对钙的需求。关于纯母乳喂养（4 至 6 个月）导致骨密度测定的原因和参与比例，文献尚无定论。本文旨在系统地回顾文献，以确定在 4 至 6 个月的纯母乳喂养期间，母体骨矿物质密度 (BMD) 变化的发生率、强度和相关因素。搜索描述符“女性”、“母乳喂养”、“母乳”和“骨矿物质密度”被用于虚拟健康图书馆、Scielo（在线科学电子图书馆）、CAPES 期刊门户、LILACS、Embase、 2023 年 6 月 PubMed/Medline、Cochrane、Scopus 和 Web of Science。母乳喂养母亲的纳入标准为：年龄至 40 岁、初产妇、纯母乳喂养，使用双能 X 射线吸收测定法 (DXA) 进行 BMD 评估，数值以基线和产后 4 至 6 个月表示。采用贾达德量表、纽卡斯尔-渥太华量表和牛津循证医学中心证据水平来评估研究的质量。对于荟萃分析研究，进行了统计计算。最初，使用搜索策略找到了 381 篇文章，其中 26 篇被完整阅读。经过偏倚风险分析后，16 篇文章仍保留在系统评价中，4 篇文章纳入荟萃分析。研究表明，与较长时间的母乳喂养（12-18 个月）相比，产后头几个月（4-6 个月）腰椎骨量有所减少。母乳喂养组在荟萃分析中比对照组（非母乳喂养、怀孕或产后立即）产生了更大的影响，腰椎 BMD 降低了 -0.18 g/cm2（-0.36、-0.01 g/cm2） /cm2）； 95% 置信区间，范围为 0 到 10。我们的结果表明，在 4 到 6 个月的纯母乳喂养期间，腰椎骨密度暂时降低，并在产后期逐渐恢复。需要更多的前瞻性研究来更好地理解这个主题。 PROSPERO 平台（编号 CRD42021279199），2021 年 11 月 12 日。