Real-world treatment outcomes in pregnancy and lactation-associated osteoporosis: a nationwide multicenter cohort study.

Background: Pregnancy and lactation-associated osteoporosis (PLO) is an uncommon cause of fragility fractures in young women, and the optimal treatment strategy remains unclear. This study aimed to investigate the clinical features, treatment approaches, and bone mineral density (BMD) outcomes of women with PLO across multiple centers in Türkiye. Methods: This multicenter retrospective cohort study included 59 women with PLO from 18 endocrine centers in Türkiye. Data on demographics, clinical and laboratory results, fractures, treatments, and bone density were collected. Changes in the lumbar spine, femoral neck, and total hip BMD were tracked. Additionally, lumbar spine BMD outcomes were compared between women who received teriparatide and those managed with calcium/vitamin D alone. Results: The mean age at diagnosis was 29.1 ± 4.8 years. Overall, 86.4% of patients had vertebral fractures, and 67.8% had multiple fractures. Of the 59 patients, 10 received bisphosphonates, 3 received denosumab, 22 received TPTD, and 24 received calcium/vitamin D supplementation alone as first-line treatment. Lumbar spine BMD improved significantly in all treatment groups and total hip BMD in the teriparatide and calcium/vitamin D groups, whereas femoral neck BMD improved significantly only in the teriparatide group. Women receiving TPTD demonstrated greater early improvement in lumbar spine BMD than those managed with calcium/vitamin D alone (19.1% vs 9.5%; Hodges-Lehmann median difference, 11.5 percentage points [95% CI, 1.5 to 22.8]; P = 0.019). However, the between-group difference in lumbar spine BMD improvement was no longer significant at the second follow-up. After adjustment for baseline lumbar spine BMD, age, BMI and multiple vertebral fractures, treatment group was no longer independently associated with early lumbar spine BMD change (B = 3.0 percentage points, 95% CI -12.8 to 18.9; P = 0.698). Conclusions: Women with PLO showed substantial recovery in bone density during follow-up across treatment groups. Although women receiving TPTD demonstrated greater early lumbar spine BMD improvement in unadjusted analyses, this association was not independent after multivariable adjustment, and between-group differences were no longer observed during later follow-up. Prospective comparative studies are needed to define the optimal treatment strategy.