Skeletal muscle ultrastructure in normal pregnancy and preeclampsia

The aim of this study was to assess by quantitative methods whether the assumed metabolic disturbance underlying preeclampsia would be reflected in muscle cell composition of lipid, mitochondria, or glycogen. We have reported mitochondrial dysfunction in preeclampsia, and since accumulation of lipid in skeletal muscle is a feature in mitochondrial disorders, our hypothesis was that preeclamptic women would have an increased content of triglyceride droplets. Quantitative investigation of the skeletal muscle ultrastructure was performed in 10 women with severe preeclampsia and in 6 normotensive pregnant women. Biopsy specimens from musculus rectus abdominis were taken during cesarean section and prepared for electron microscopy. Random pictures were taken by transmission electron microscopy, and point-counting stereology was performed. Preeclamptic women did not have a higher lipid volume fraction than normotensive pregnant women, and we had to reject our hypothesis. On the contrary, there was a tendency towards a lower triglyceride volume fraction in pre eclampsia. We did not detect differences in relative volumes of mitochondria or glycogen in skeletal muscle between the two groups.