337Mothers with pregnancies complicated by uteroplacental insufficiency do not have impaired bone mineral content, density or strength during and after lactation
Section snippets
Background and aims
Uteroplacental insufficiency is a complication arising in 10% of human pregnancies and is characterised by reduced placental blood flow, with a reduction of oxygen and nutrient supply to the fetus resulting in intrauterine growth restriction. We have previously shown in the rat that pups born to mothers with uteroplacental insufficiency are born of low birth weight, have lower total body calcium content and consume milk with lower calcium as a consequence of reduced placental and mammary
Study design
To induce uteroplacental insufficiency, bilateral uterine vessel ligation (Restricted) or sham surgery (Control) was performed on gestational day 18 (term = 22 days) in WKY rats. Post mortem of Control and Restricted mothers was performed on day 1, day 35 (weaning), 7 weeks and 9 weeks post partum. The right femur was dissected and femur length, dimensions, mineral content and density were measured at both trabecular and cortical sites using peripheral quantitative computed tomography (pQCT).
Results
Restricted pups were born lighter than Controls (p < 0.05). There were no differences in maternal body weight between the Control and Restricted groups at any time point. Femur trabecular and cortical mineral content and density were not different between groups. Measures of bone geometry, including periosteal and endosteal circumferences, as well as cortical thickness were not different between groups. The stress strain index of bone bending strength was also not different when comparing the
Conclusions
These results suggest that mothers with pregnancies complicated by uteroplacental insufficiency do not have a bone deficit. Maternal bone homeostasis is unable to compensate for the adverse consequences of uteroplacental insufficiency on placental and mammary calcium transfer to the growth restricted offspring.