Adolescent pregnancy; a determinant of bone mineral density in peri-menopausal women?

The present study aims to determine the effects of a history of adolescent pregnancy (AP) on the bone mineral density (BMD) of perimenopausal women.

Overall, 240 women aged between 40 and 55 years, with a complaint of oligomenorrhea or amenorrhea not exceeding 1 year in duration, were evaluated. Evaluation included a DEXA scan and a detailed demographic survey for bone health. Comparison was made between women with a history of AP and those without.

In total, 87 women who had a history of AP were compared with 153 women who did not have a history of AP. The study groups did not differ significantly for most of the evaluated demographic factors. Women with a history of AP had higher gravidity and parity. Comparison of T-scores revealed lumbar BMD to be unaffected by AP (P=0.184), whereas femoral BMD was positively influenced by a history of AP (0.78±0.65 vs -1.06±0.67; P=0.042). In covariance regression models, after adjusting for parity and age of first menarche, AP still positively influenced femoral BMD. Without a history of AP, women were at increased risk for osteoporosis of femoral neck (odds ratio, 2.8, 95% CI 1.75-4.8).

The effects of AP on BMD are not well elucidated. Women with a history of AP had better femoral BMD scores, indicating a possible protective influence of AP on bone health.

Pregnancy during adolescence is associated with a better femoral bone mineral density than pregnancy at an older age. However, the effects did not extend to lumbar spine bone mineral density.