Fertility factors linked to osteoporosis risk

Women with a history of infertility, miscarriage or stillbirth, and low parity are at increased risk of osteoporosis, as suggested in a study.

Researchers used data from five retrospective and prospective cohorts within the International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events. They looked at 141,222 naturally postmenopausal women with data on fertility factors (ie, infertility, miscarriage, stillbirth, or parity), osteoporosis, and covariates (ie, race, age at last follow-up, education level, smoking status, alcohol intake, BMI, physical activity level, and age at menarche).

The history of infertility, miscarriage, stillbirth, and parity was self-reported. Osteoporosis was ascertained using surveys, hospital, death registry, primary care, or pharmaceutical data.

In multivariate Cox regression models, the risk of osteoporosis was modestly elevated in women with a history of infertility (hazard ratio [HR], 1.16, 95 percent CI, 1.13–1.19), recurrent miscarriages (≥3; HR, 1.17, 95 percent CI, 1.05–1.30), stillbirth (HR, 1.14, 95 percent CI, 1.10–1.17), and low parity (no live births: HR, 1.20, 95 percent CI, 1.15–1.25; one live birth: HR, 1.15, 95 percent CI, 1.14–1.16).

These associations persisted or were only slightly attenuated in an analysis that adjusted for age at natural menopause.

The findings highlight the importance of considering female-specific factors as part of the risk assessment for osteoporosis, as well as inform prevention strategies.