The influence of lactation on BMD measurements and TBS: a 12-month follow-up study.

Although lactation is associated with transient bone loss and body weight changes, the unchanged TBS could highlight a limited effectiveness in detecting dynamic bone properties in the first year postpartum. PURPOSE: To evaluate trabecular bone score (TBS) and bone mineral density (BMD) in postpartum women. METHODS: This was a 12-month prospective cohort study with 40 lactating postpartum women and 44 non-pregnant women. The inclusion criteria were as follows: aged between 18 and 35 years old, an uncomplicated term (≥37 weeks) pregnancy with a single fetus, and no intention of becoming pregnant within 12 months. BMD measurements, including spine, hip, forearm and whole body, were performed by DXA at four different time points after delivery: (1) 1st month, (2) 3rd-4th month, (3) 6th-9th month, and (4) ≥ 12th month postpartum. RESULTS: BMD measurements showed a statistically significant decrease at spine (1.134 vs. 1.088 g/cm2, p < 0.01), femoral neck (0.988 vs. 0.946 g/cm2, p < 0.01), total femur (0.971 vs. 0.933 g/cm2, p < 0.01), and whole body (1.132 vs. 1.119 g/cm2, p = 0.03) at the 2nd assessment (peak of lactation). There was early spinal recovery after the 3rd assessment with complete recovery in all skeletal sites. Although it has had significant weight loss (67.3 vs. 63.2 kg, p < 0.01) and body mass index reduction (25.2 vs. 23.4, p < 0.01), there was significant increment of spine BMD (1.134 vs. 1.165 g/cm2, p < 0.01) after 12-month follow-up. The TBS did not change over time. CONCLUSIONS: Although lactation is associated with transient bone loss and body weight changes, the unchanged TBS could highlight a limited effectiveness in detecting dynamic bone properties in the first year postpartum.

How does women's bone health recover after lactation? A systematic review and meta-analysis.

This is a systematic review aiming to evaluate the recovery of bone mass after lactation-related loss. Bone loss is transitory with recovery depending on the return of menstruation and weaning, and several compensatory homeostatic mechanisms are involved to minimize any significant damage to the maternal skeleton. Lactation has been associated with significant temporary bone loss, especially during the exclusive breastfeeding period. In the bone recovery phase, there is wide methodological heterogeneity among clinical trials, including follow-up timing, methods and sites of bone measurements, and body composition changes. The purpose of this study is to perform a systematic review and meta-analysis aiming to evaluate the recovery rate of bone mass after lactation-related loss, including the PubMed, Web of Science, and Scopus databases, with no publication date restrictions. The following MeSH terms were used: "bone diseases," "bone resorption," "bone density," "osteoporosis," "calcium," "postpartum period," "weaning," "breast feeding," and "lactation." The inclusion criteria were as follows: prospective human studies in women of reproductive age and bone measurements with two assessments in the postpartum period at least: the first one within the first weeks of lactation and another one 12 months after delivery, 3 months following the return of menses or 3 months postweaning. This research was recorded on the Prospero database (CRD42018096586Bone). A total of 9455 studies were found and 32 papers met the inclusion criteria. The follow-up period ranged from one to 3.6 years postpartum. Lactation was associated with transient bone loss, with a strong tendency to recover in all the sites studied, depending on the return of menstruation and weaning. Small deficits in the microarchitecture of the peripheral skeleton may be present, especially in women with prolonged breastfeeding, but with no deficit regarding the hip geometry was found. Women with a successive gestation after prolonged lactation and women who had breastfed when adolescents had no significant bone loss. Bone loss related to lactation is transitory, and several compensatory homeostatic mechanisms are involved to minimize any significant damage to the maternal skeleton.