A Case of Teriparatide on Pregnancy-Induced Osteoporosis
Patient: A 39-year-old woman\nChief complaint: Low back pain\nCurrent medical history: A woman began to have low back pain at 2 months after vaginal birth. She had no significant past medical history. Her low back pain exacerbated at 3 months after delivery. Magnetic resonance imaging (MRI), provided by the previous hospital, revealed multiple compression fractures (L1-L5) on her lumbar vertebrae. On admission, the patient was breastfeeding after her first birth.\nFamily history: Her father had lung cancer.\nPast history: The patient had sympathectomy due to hyperhidrosis. However, she had no history of other drug.\nPhysical findings: On physical examination, her blood pressure was 110/70 mmHg and her pulse was 72/minute. Height was 156 cm, weight was 50 kg, and body mass index was 20.5 kg/m2. No lump felt in thyroid gland. Neither abdominal tenderness nor hepatosplenomegaly was detected. Tenderness was present on lower back.\nLaboratory findings: Peripheral blood examination revealed white blood cells 7,660/µL, hemoglobin 13.4 g/dL, platelet 218,000/µL, aspartate aminotransferase (AST)/alanine aminotransferase (ALT) 19/24 IU/L, blood urea nitrogen (BUN) 18.0 mg/dL, creatinine 0.76 mg/dL, calcium 9.7 mg/dL (8.2-10.4) , and phosphorus 4.2 mg/dL (1.9-4.4). Thyroid stimulating hormone (TSH) was 1.73 µIU/mL (0.35-5.58) and free thyroxine was 1.49 ng/dL (0.89-1.76). Luteinizing hormone was 0.8 mIU/mL (0.1-6.0), estrogen was 51.23 pg/mL (150-350), estradiol was 34.85 pg/mL (22-250), 24-hour urine cortisol was 26.51 µg/day (10-121), and urinary calcium was 259 mg/day (100-300). Parathyroid hormone (PTH) was 10.6 pg/mL (14-72), serum 25-hydroxy-vitamin D was 28.80 ng/mL (30-100), serum alkaline phosphatase was 332 IU/L (104-280), osteocalcin was 30.46 ng/mL (11-30), and cross-linked C-terminal telopeptide of type I collagen (CTX) was 1.15 ng/mL (0.01-0.60).\nRadiologic examination: Lateral view of lumbar vertebrae detected a loss of vertebral height in L1-L5 (). MRI exhibited multiple compression fractures in the same lumbar region (). Bone scan revealed increased uptake in left 6-8th ribs and L1-L5 (). On dual energy X-ray absorptiometry (DXA), L1-L4 Z-score was -2.2, and BMD value was 0.855 g/cm2. However, it was difficult to assess the condition correctly due to compression fractures. Femur neck Z-score was -1.4 on both sides, and BMD value was 0.754 g/cm2 ().\nTreatment and outcome: After the diagnosis of pregnancy-associated multiple compression fractures, the patient was given oral bromocriptine 2.5 mg once daily for a week to stop breast feeding. Once breastfeeding stopped, the patient was given oral administration of calcium 3,000 mg and vitamin D (cholecalciferol 800 IU) and daily subcutaneous injection of 20 µg of teriparatide. In 4-month follow-up, serum calcium was 9.4 mg/dL, phosphorus was 3.5 mg/dL and, PTH was 19.1 pg/mL, showing normal ranges. Serum osteocalcin increased to 62.24 ng/mL, compared with the baseline value, whereas alkaline phosphatase decreased to 239 IU/L, CTX 0.608 ng/mL. The Z-score and mean BMD values improved to -0.7 and 1.040 g/cm2, respectively. Low back pain gone and teriparatide has been prescribed for 10 months at outpatient clinic during follow-up examination.