Progressive Idiopathic Juvenile Osteoporosis in Pregnancy: A Case Report of Two Successive Pregnancies in the Same Woman

A 33-year-old primiparous woman with progressive idiopathic juvenile osteoporosis (IJO) who had had multiple vertebral compressions and bilateral femoral neck fractures since the age of 15 years presented for perinatal management at 11 weeks of gestation. Her vertebral bone mass was 0.634 g/cm before pregnancy. The target calcium intake was set at 800 mg/day. Cephalopelvic disproportion led to the patient having an elective cesarean section at 39 weeks 3 days of gestation and she delivered a female infant weighing 2785 g. After the delivery, her vertebral bone mass had increased to 0.700 g/cm. At 34 years of age, she conceived her second child. With similar perinatal management, she delivered a female infant weighing 2580 g at 38 weeks of gestation by elective cesarean section. Her vertebral bone mass had increased again after the second pregnancy. Few cases of pregnancy complicated by progressive IJO have been reported. However, an uneventful pregnancy course can be expected with proper management, and pregnancy can be a good opportunity to increase bone mass.