Blood pressure and the Cardiovascular system   

Evidence Summary  

Three cross-sectional studies by the same group have investigated the role of physical activity in women who had preeclampsia during pregnancy. The same cohort (n=20) were evaluated at 6-12 months postpartum against a healthy control group (n=24) in all studies. Women underwent a 12-week supervised cycling programme at 70-80% VO2max.    

Exercise training was shown to be effective in diminishing retrograde shear rate, improved flow mediated dilatation (both related to endothelial function) and autonomic balance (P<0.05) in both the study and control groups – thus improving cardiovascular function.[1] Plasma volume was shown to increase in both groups (low plasma volume (≤1373 mL/m2) is associated with recurrent preeclampsia and chronic hypertension), though did not reach statistical significance (p=0.22).[2] Low plasma volume is hypothesised to be secondary to reduced venous compliance, which improved significantly in the study group versus the control (p<0.01). Finally, the group demonstrated the cardio-protective effects of training on both groups through improved endothelial function, vascular structure. autonomic function and decreased values of most components of metabolic syndrome. Fasting insulin levels demonstrated statistically significant improvement post intervention (P<0.05).[3]   

Quality of evidence  

Grade C – Evidence presented comes from 3 cross-sectional studies of the same cohort of women, with a small sample size. Though there are promising initial results, due to the nature of the studies the quality of the evidence at present is weak, and further robust studies are needed to provide more conclusive guidance.    

Strength of recommendation  

Strong recommendation – There were no harmful outcomes from the studies and the overall benefit of physical activity would outweigh any risks.  

Conclusion 
  
Current evidence supports physical activity in post-partum women who had preeclampsia during pregnancy, despite there been a paucity of studies. The short duration of the studies (12 weeks) would not provide a true reflection of the cardiovascular adaptations which may take much longer to take place, and likely resulted in the studied group only reaching the pretraining levels of the control group in many of the parameters.   

References  

1. Scholten, R.R., et al.,Retrograde shear rate in formerly preeclamptic and healthy women before and after exercise training: relationship with endothelial function.Am J Physiol Heart Circ Physiol, 2014. 307(3): p. H418-25.  

2. Scholten, R.R., et al.,Aerobic Exercise Training in Formerly Preeclamptic Women:Effets on Venous Reserve. Hypertension, 2015. 66(5): p. 1058-65.  

3. Scholten, R.R., et al.,Cardiovascular effects of aerobic exercise training in formerly preeclamptic women and healthy parous control subjects.Am J Obstet Gynecol, 2014. 211(5): p. 516 e1-516 e11.