Physical exercise has been demonstrated a positive effect on many pregnancy outcomes. Placental components are important for exchanging oxygen and nutrients between mother and fetus. This study aimed to systematic review and meta-analysis whether physical exercise could induce a morphological adjustment on placenta components. We systematically searched PubMed database until October 30th, 2014. We included randomized and non-randomized studies with control group, which aimed to investigate the effect of the physical exercise (water, aerobic and resistance) on placental components (placental weight and volume, villous volume and vascular volume, intervillous space and stem villi). Initially, we identified 222 articles, of which 9 articles were used for full text analysis. Finally, four articles were included in the systematic review and meta-analysis. Meta-analysis demonstrated that exercise appeared to affect placental weight (95% CI, 39.73g [4.66-74.80]), placental volume (95% CI, 47.11 cm3 [37.99-56.23]), intervillous space (95% CI, 16.76 cm3 [12.66-20.68]), villous volume (95% CI, 46.01 cm3 [40.21-51.81]), villous vascular volume (95% CI, 15.95 cm3 [7.83-24.07]) and stem villi (95% CI, 6.00 cm3[4.25-7.75]). Apparently, physical exercise has a positive effect on placental components. However, this conclusion is based on a limited number of studies. Clearly, it stands the necessity of larger samples and better methodology quality.
placenta; chorionic villi; physical exertion; pregnancy
