Category: Calcium/Bone Disorders

Monitor: 24


Friday, Apr 26
12:30 PM – 1:00 PM

Objective :


Methods : N/a

Results : N/a

Discussion :

A 34-year-old female developed sudden severe back pain 8 weeks after her first delivery. She denied trauma, strain or falls. Medical history included well-controlled hypothyroidism, and medications were levothyroxine and a multivitamin. She used to exercise regularly at a moderate intensity. Her gestation and delivery were uncomplicated. She exclusively breastfed her newborn. On exam, height was 151 cm, with evident loss of height (formerly 153 cm); weight was 42.7 kg (body mass index was 18 kg/m2). She had scoliosis and tenderness in the thoracic spine. MRI showed compression fractures at the levels of T5, T6, T7 and T11. Basic chemistry, thyroid function studies, 25-hydroxyvitamin D, calcium, phosphorus, magnesium, intact parathyroid hormone and alkaline phosphatase were all within normal limits. Bone mineral density (BMD) by dual energy X-ray absorptiometry (DEXA) confirmed osteoporosis (spine L1- L4 Z score - 4, T score -4.7, BMD 0.615 g/cm2; hip Z score -3.1, T score -3.6, BMD 0.562). Treatment started with interruption of breastfeeding, ergocalciferol 2000 IU, calcium carbonate 1000 mg, and teriparatide 20 mcg per day. After two years of treatment, spine BMD improved to 0.829 g/cm2 (Z score -2.3, T score -2.9). She received a single dose of zoledronic acid 5mg. A year later, therapy was continued with denosumab until present. Latest DEXA shows spine BMD of 0.757 g/cm2 (Z score -2.4, T score -2.6).

Pregnancy or lactation-related osteoporosis is a rare condition diagnosed during the last trimester of pregnancy or early postpartum. There are very few cases reported, with no clear epidemiology available [1,4]. Sudden fractures may present with severe pain during or soon after pregnancy in otherwise apparently healthy women. Severe back pain has been reported multiple times as the presenting symptom [1,2]. Normally, bone density decreases in the later months of gestation and regenerates following birth. Also, bone density may decline during breastfeeding but returns to normal when the infant is weaned.  Although the pathophysiology remains unclear, several possible mechanisms have been suggested [4]. The age-specific prevalence of osteoporosis is less than 2% in women younger than 50 years. Between the ages of 20 and 40 years, the prevalence of osteoporosis is only 1.2% [1,4].


Conclusion :

Pregnancy associated osteoporosis should be considered as a possible etiology of postpartum back pain.


Jessica L. Betancourt

University of South Florida Morsani College of Medicine
Tampa, Florida

Endocrinology Fellow

Laura Oben-Perez

Universiy of South Florida Morsani College of Medicine

Endocrinology Fellow

Alejandro Ramirez

Assistant Professor of Medicine
University of South Florida Morsani College of Medicine

Assistant Professor of Medicine Endocrinology Section

John Tourtelot

Assistant Professor of Medicine
Moffitt Cancer Center

Assistant Professor of Medicine