Knowledge Bank

During pregnancy, physiologic adaptations preserve maternal homeostasis while promoting fetal growth. Adaptations in the cardiovascular system and metabolic processes ensure adequate nutrients are available to the fetus while maintaining maternal homeostasis. For most women, these adaptations to pregnancy are tolerated uneventfully. In 2-8% of pregnancies, these maternal metabolic changes are not tolerated, resulting in more exaggerated increases in insulin resistance, LDL cholesterol, and triglycerides, as well as a reduction in HDL cholesterol (Roberts & Hubel, 2010). These metabolic abnormalities are present in the hypertensive pregnancy complication, preeclampsia. Preeclampsia shares risk factors and pathological features with cardiovascular disease. In both disorders, dyslipidemia and endothelial dysfunction are present and are associated with sedentary lifestyle and obesity. Some suggest that pregnancy is a cardiovascular stress test, and complications such as preeclampsia and gestational diabetes identify women who would benefit from preventative intervention to reduce cardiovascular disease. In the study “Exercise Intervention to Reduce Recurrent Preeclampsia” (RO1 NR05375), a group of women with a history of preeclampsia and a self-reported sedentary lifestyle were randomized into a walking group (n=62) and control group (n=61). Women were followed from the first trimester through delivery, and lipid profiles were assessed at 15.96±3, 24±2, and 36±2 weeks gestation. It was hypothesized that 30 minutes of physical activity, 5 days per week would minimize increases in glucose, triglycerides, and LDL and minimize decreases in HDL. Those in the walking group showed a significantly lower level of LDL (116.8±6.5 for walkers and 137.2±6.5 for controls, p=0.03) at 24±2 weeks gestation, but the intervention did not affect total or HDL cholesterol (p=0.10 and 0.68, respectively). This suggests that physical activity during pregnancy may minimize the increase in LDL or in other words, the “bad” cholesterol. Future analysis of this data in relation to (1) the participant’s adherence to physical activity, (2) body mass index, and (3) recurrent preeclampsia will enhance the understanding of these findings.