Subsequent fracture risk of women with pregnancy-associated osteoporosis after a median of 6 years of follow-up

Introduction:

Pregnancy-associated osteoporosis (PAO) is a severe type of premenopausal osteoporosis which predominantly occurs in the last trimester of pregnancy or immediately postpartum. Long-term follow-up data including subsequent fracture risk have yet to be reported.

Methods:

This single-center prospective cohort study investigated the subsequent fracture risk of all 121 patients with PAO who were referred to our institution because of minimal trauma fracture or low bone density according to age.

Results:

Of 121 patients with PAO, 107 (88.4%) sustained at least one fracture. Each patient suffered on average from 4 fractures most commonly at the thoracolumbar spine. During the six years of follow up, 26 (24.3%) of patients who had a fracture at baseline reported a subsequent fracture. Overall, 62 PAO patients (51.2%) reported a further pregnancy. In subsequent pregnancies, 12 (20%) of patients with a previous fracture and 10 (16.7%) of patients without a previous fracture reported a subsequent fracture with no statistically significant differences between the two groups (p = 0.851). Patients with up to 1 vs. > 1 fracture at time of diagnosis showed a 3 (10%) and 25 (27%) subsequent fracture rate, respectively (p = 0.047). With regard to Bone Mineral Density, women with PAO receiving osteoporotic treatment showed an initial increase, followed by subsequent stabilization.

Conclusions:

Subsequent fracture-risk after PAO is comparable to that in women with postmenopausal osteoporosis and should not be disregarded. Patients with PAO need to be informed about their potential subsequent fracture risk before deciding for further pregnancies.