Prevalence of pregnancy- and lactation-associated osteoporosis in the postpartum period: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to estimate the prevalence of pregnancy- and lactation-associated osteoporosis in postpartum women within 1 year of delivery. We searched MEDLINE via PubMed and Igaku Chuo Zasshi for articles published in English or Japanese from the inception of the database to September 2021. Two researchers independently screened and included observational studies reporting the prevalence of pregnancy- and lactation-associated osteoporosis in postpartum women within 1 year of delivery. Of the 3,425 screened records, 8 articles centered on postpartum women were included in the review. Seven studies used dual-energy X-ray absorptiometry for assessing bone mineral density, while one used a quantitative ultrasound method. In the seven studies that used dual-energy X-ray absorptiometry, the parameters used to define osteoporosis were the T-score (two studies), Z-score (three studies), both T- and Z-scores (one study), and young adult mean (one study). Evaluation timeframes included 1 week (three studies), 1-2 months postpartum (three studies), and 1 week to 12 months postpartum (one study). The estimated prevalence of pregnancy- and lactation-associated osteoporosis defined by dual-energy X-ray absorptiometry was as follows: lumbar spine (six studies), 5% (95% confidence interval [CI], 0-13; heterogeneity [I2] = 99%) and femoral neck (three studies), 12% (95% CI, 0-30; I2 = 99%). Pregnancy and lactation were found to elevate the fracture risk in women, underscoring the necessity for a standardized assessment in diagnosing pregnancy- and lactation-associated osteoporosis. This imperative step aims to enable early detection and treatment of bone mineral loss among postpartum women.