Bilateral transient osteoporosis of the hip: a neglected cause of hip pain during pregnancy.

Transient osteoporosis of the hip (TOH) is an important but often neglected cause of hip pain, which can gradually lead to debilitating mobility and carries risks such as fracture or avascular necrosis. A 39-year-old woman presented to the Rheumatology department two weeks post-cesarean delivery, reporting the onset of left mechanical hip pain since the 33rd week of pregnancy. After delivery, similar complaints emerged on the right side. Hip X-ray showed a decrease in bone density in the left hip. Later, Magnetic Resonance Imaging revealed bilateral bone marrow edema in both proximal femurs. The diagnosis of TOH was established, and the patient was treated with conservative measures. Seven months later, she was asymptomatic. Pregnancy is a recognized risk factor for TOH, especially in the last trimester. It is an important differential diagnosis to consider in cases of hip pain in pregnant or newly breastfeeding women.