Influence of pregnancy on bone density: a risk factor for osteoporosis? Measurements of the calcaneus by ultrasonometry.

BACKGROUND

There are conflicting opinions in the literature about whether pregnancy influences maternal bone density or osteoporosis development. The study aim was to investigate whether there is a significant alteration in maternal bone density during normal pregnancy.

METHODS

Bone mass of 200 pregnant women aged 22-42 years was measured twice with quantitative ultrasonometry (QUS) of the heel (Os calcaneum). The first measurement was performed between the 10th and 22nd week of pregnancy, follow-up of 149 women took place 0-9 days postpartum. A questionnaire focusing on data affecting bone metabolism and bone turnover was handed out at the first visit.

RESULTS

Median reduction in speed of sound (SOS) was 11 m/s at follow-up indicating a decline of the stiffness during pregnancy. No significant correlation was found between lactation period and the obtained values for stiffness, SOS, T score and Z score. For broadband ultrasonographic attenuation, there was a statistically significant difference (p < 0.05) between women who had and had not breastfed. Parameters from patients with a family history of osteoporosis (n = 30) compared to patients without did not reveal statistical significance during pregnancy. Glucocorticoid therapy, nicotine consumption, physical exercise and nutrition was not statistically significant (p > 0.05). SOS value of women with a twin pregnancy was different over the study period (p < 0.05).

CONCLUSION

A reduction in bone mass is possible during pregnancy. Routine evaluation of the bone density in all pregnant women does not seem to be justified; however, it is reasonable in women who present with risk factors. These women could be screened with QUS.