087. PREGNANCY-ASSOCIATED OSTEOPOROSIS: A UK CASE SERIES

Abstract

Background: Pregnancy-associated osteoporosis is a rare syndrome affecting women during late pregnancy and in the early post-partum period, which may result in fragility fractures. We describe ten cases of pregnancy-associated osteoporosis from a single UK centre. Methods: Patients had attended the osteoporosis clinic at the Royal National Hospital for Rheumatic Diseases, Bath, between January 2000 and June 2016. The principal inclusion criterion was the occurrence of low trauma fractures either during pregnancy, or up to 18 months post-partum. Data were obtained from retrospective review of medical notes. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (Hologic Discovery system) at the lumbar region of L1-L4 and both hips. Radiographic fractures were further characterized using MRI. Data pertaining to the pregnancy, as well as type and duration of treatment received, were reviewed. Results: The ten cases are summarized in Table 1. All presented with vertebral fractures, and in all cases Z-scores at the lumbar spine were lower than those at the hip. In four patients, no risk factors for fracture other than pregnancy or breastfeeding could be identified. Four patients were found to have insufficient levels of vitamin D at the time of diagnosis. In addition, two patients had received treatment with low molecular weight heparin (LMWH) which could potentially have contributed to their osteoporosis. In one case, further investigations led to a diagnosis of osteogenesis imperfecta, confirmed on genetic testing. Although her presentation was similar to that of the other cases, the history of several prior fractures during childhood suggested bone loss at a younger age. In terms of treatment, eight out of the ten patients in this series received a bisphosphonate, most commonly risedronate due to its relatively short skeletal retention time. Conclusion: Rheumatologists should be aware of pregnancy-induced osteoporosis, a rare but recognized complication of pregnancy. The condition should be especially considered in women presenting with new onset back pain in pregnancy or the post-partum period. (Table Presented).