Premature ovarian insufficiency (POI) is associated with decline in bone density¹. Data regarding contributory factors and optimal replacement of oestradiol are limited. We aim to describe the bone health burden of disease in women with POI. This study reports baseline characteristics with a view to collecting long-term observational data. 

We conducted a retrospective evaluation of patients attending The Royal Hospital for Women POI Clinic between November 2024 and June 2026. Baseline clinical characteristics, diagnosis, hormone replacement, biochemistry and dual-energy x-ray absorptiometry (DEXA) results were collected. For patients with pre-existing diagnosis of POI, time to initiation of therapy and duration of therapy were noted. 

There were 53 patients seen in the POI Clinic. Median age at diagnosis of POI was 38 years (IQR: 30-42). Of the 53 patients, 45 had undergone DEXA (Table 1); 16 had not commenced hormone therapy prior to initial review. Three patients had reduced bone density for age with Z-score <-2.0 standard deviations (SD) at any measured site, and 1 woman had a Z-score exactly -2.0 SD. Of these patients with reduced bone density, there was a delay from initial diagnosis to initiation of menopausal hormone therapy (MHT) in 2 women (2 and 20 years respectively). Another was treated with the combined oral contraceptive pill (COCP) containing levonorgestrel/ethinylestradiol 50/30 mcg, and 1 with low dose oral oestradiol 1 mg. Levels of 25-hydroxyvitamin D were largely replete >50 nmol/L across the cohort (37/42). 

Most women in the baseline cohort had bone density within expected range for age, however a small number demonstrated reduced bone density. Further studies are required to assess efficacy of hormone replacement at maintaining bone density in women with POI. This cohort will be followed prospectively to better characterise possible contributory factors, including age at diagnosis, delay to therapy and formulation of oestradiol replacement.