Transient Osteoporosis of the Hip in the Third Trimester: A Report of a Rare Case.

Transient osteoporosis of the hip (TOH) is an uncommon, self-limiting condition characterized by acute hip pain and bone marrow edema, which presents in the third trimester of pregnancy. Despite its rarity, TOH can significantly affect maternal mobility and quality of life, highlighting the need for timely recognition and appropriate management. A 28-year-old primigravida presented at 32 weeks of gestation with sudden onset bilateral hip and lower back pain, unresponsive to conservative measures. Laboratory tests ruled out infection and inflammatory causes, and a magnetic resonance imaging (MRI) scan of the hips revealed characteristic bone marrow edema, confirming TOH. Multidisciplinary management included thromboprophylaxis, pain control, and limited weight-bearing. Due to severe pain and compromised mobility, an elective cesarean section was performed at 36 weeks. Postoperatively, her symptoms improved significantly within days. A postpartum dual-energy X-ray absorptiometry scan showed osteopenia, consistent with transient demineralization. At six weeks postpartum, she demonstrated near-complete resolution of symptoms. This case underscores the importance of maintaining a high index of suspicion for TOH in pregnant patients with sudden onset severe hip pain. Magnetic resonance imaging remains the gold standard for accurate diagnosis, and a multidisciplinary approach facilitates safe delivery and effective postpartum recovery. Although the prognosis is favorable, careful follow-up is essential to monitor bone health and mobility in the postpartum period.