Low molecular weight heparin as a risk factor for pregnancy-and lactation-associated osteoporosis
Yerasuri DK, and Honasoge M. Low molecular weight heparin as a risk factor for pregnancy-and lactation-associated osteoporosis. Endocr Rev 2018; 39(2)
Introduction: Pregnancy-and lactation-associated osteoporosis (PLO) is a rare form of osteoporosis, that can cause several vertebral fractures with disabling back pain. Young women on low molecular weight heparin (LMWH) during pregnancy are at an increased risk for PLO. Data is very limited on the association LMWH and postpartum osteoporosis. We report a case of a young woman on long term LMWH use who presented with multiple vertebral fractures Case: A 26 y/o woman who was 2 months postpartum presented with sudden onset of severe back pain. Past medical history significant for recurrent deep vein thrombosis, factor V Leiden disease and use of low molecular weight heparin during pregnancy. MRI of lumbosacral spine showed compression deformities involving superior endplate of L2-L5 vertebral bodies. Bone density showed Z score of -2.4 in lumbar spine,-1.6 in total hip and -1.3 in femoral neck. No family history of osteoporosis, and work up for secondary osteoporosis negative. Bone scan showed superior endplate fractures of T9, T11, T12 and L1. Lactation was stopped and she was started on treatment with Teriparatide. Her back pain improved. A repeat MRI was done after 4 months of treatment as she complained of back spasms, that showed well healed fracture. Discussion: Pregnancy and lactation are known risk factors for osteoporosis. Hormonal changes during lactation cause 5-10% loss of trabecular mineral content in order to provide calcium in milk. Women with risk factors for secondary bone loss and fragility are at increased risk of fracture. Long term use of heparin can cause bone loss by decreased formation and increased resorption. Bone loss can be seen after 6 months of therapy with heparin. With increasing use of LMWH during pregnancy for various indications this can be considered as a new risk factor for PLO. This case illustrates the fact that clinicians should have a high suspicion for PLO in young women with LMWH use.