osteoporosis is common in people aged 50 and over , but the disease can strike the younger age groups . osteoporotic fracture associated with pregnancy and breast feeding is rare , so its treatment is not well understood , not to mention the natural course of treated osteoporotic fracture . parathyroid hormone - related protein ( pthrp ) is likely to be responsible for osteoporotic fracture . the symptom is also claimed as the consequence of disturbed bone formation during pregnancy in which bone resorption continued until mid - pregnancy while bone formation remains slow until 28 weeks . we experienced a case of a woman who had osteoporotic fracture three months after delivery without a history of significant disease . patient : a 39-year - old woman chief complaint : low back pain current medical history : a woman began to have low back pain at 2 months after vaginal birth . magnetic resonance imaging ( mri ) , provided by the previous hospital , revealed multiple compression fractures ( l1-l5 ) on her lumbar vertebrae . on admission , past history : the patient had sympathectomy due to hyperhidrosis . however , she had no history of other drug . physical 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 / m . laboratory findings : peripheral blood examination revealed white blood cells 7,660/l , hemoglobin 13.4 g / dl , platelet 218,000/l , 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 iu / 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 g / 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 ) . radiologic examination : lateral view of lumbar vertebrae detected a loss of vertebral height in l1-l5 ( fig . 1 ) . mri exhibited multiple compression fractures in the same lumbar region ( fig . bone scan revealed increased uptake in left 6 - 8th ribs and l1-l5 ( fig . femur neck z - score was -1.4 on both sides , and bmd value was 0.754 g / cm ( table 1 ) . treatment 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 g 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 / cm , respectively . low back pain gone and teriparatide has been prescribed for 10 months at outpatient clinic during follow - up examination . therefore , it is necessary to identify a patient 's past history , including any previous surgeries and drug treatment and conduct endocrine evaluations , including hyperthyroidism , hyperparathyroidism and cushing 's syndrome . among 35 patients with pregnancy - induced osteoporosis , although the association between pregnancy and bone metabolism is uncertain , calcium is required by unborn babies to build their bone during the third trimester of pregnancy . an average daily amount around 200 - 250 mg of calcium is transferred to the fetus even during breast - feeding period . calcium and vitamin d deficiency arises as the number of pregnancies and total breastfeeding time increase . pregnancy - induced osteoporosis is caused by mechanisms in addition to amount of calcium intake and postpartum amenorrhea period . it is estimated that 33% of patients who have compression fractures as a result of pregnancy - associated osteoporosis may develop secondary fractures . treatment options for pregnancy - associated osteoporosis include medications , calcium and vitamin d supplementation and stop of breast - feeding . when calcium and vitamin d supplementation was combined with stop of breastfeeding , lumbar bmd increased by 6% in 8 months and 9.5% in 2 - 4 years . as alendronate the use of teriparatides instead of bisphosphonates for 18 months increased lumbar bmd to 36% . bisphosphonates inhibit the resorption of bone . while its half - life is short , its affinity for bone is high , extending the half - life to several years . pamidronate , a class of bisphosphonates , resulted in a transient hypocalcemia of the fetus when it was administered to a woman before her pregnancy . on the contrary , teriparatide proved to be effective in increasing bmd but reducing the risk of fractures in men and postmenopausal women . teriparatide is classified as category c in the pregnancy category system used by the u. s. food and drug administration ( fda ) . the half - life of teriparatide is an hour , which is much shorter than that of bisphosphonates , making it safe for fertile women . teriparatide 20 g was administered once a day to women with pregnancy - associated osteoporosis for 18 months . for postpartum patients with lumbago , osteoporotic fracture should be suspected .
pregnancy - induced osteoporosis is a rare disorder characterized by fragility fracture and low bone mineral density ( bmd ) during or shortly after pregnancy , and its etiology is still unclear . 
 we experienced a case of a 39-year - old woman who suffered from lumbago 3 months after delivery . 
 biochemical evidence of increased bone resorption is observed without secondary causes of osteoporosis . 
 radiologic examination showed multiple compression fractures on her lumbar vertebrae . 
 we report a case of patient with pregnancy - induced osteoporosis improved her clinical symptom , bmd and bone turnover marker after teriparatide therapy .