Maternal physiological changes at rest induced by exercise during pregnancy: A randomized controlled trial

•The study did not show differences in cardiovascular, metabolic and hepatic variables in pregnant women that underwent to a regular supervised mild-moderate exercise programme compared to controls.•This randomized study showed greater systolic pressure in women in the intervention group at 28 weeks gestation, which stabilized with respect to the control group at the end of pregnancy.•A regular supervised mild-moderate exercise programme during pregnancy does not impact the normal physiological changes that occur during pregnancy. to analyse maternal physiological changes in several areas (cardiovascular, metabolic, renal and hepatic) related to the regular practice of a supervised exercise program. This is an unplanned secondary analysis from a randomized controlled trial carried out in a single maternity unit in Madrid, Spain (NCT 02,756,143). From November 2014 to June 2015, 92 women were randomly assigned to perform a mild-moderate supervised exercise program during pregnancy (Intervention group, IG) or to continue with their routine pregnancy care (control group, CG). For the purpose of this study we collected clinical and analytical data (heart blood pressure, weight, blood glucose, AST, ALT, blood Creatinine and blood Uric acid) available from all obstetric visits and examined the differences between groups. We did not find any differences in: pregnancy weight (IG: 11.4 ± 4.4 Kg vs. CG: 10.1 ± 5.3 Kg; p = 0.173); fasting glucose at 10+0–12+6 weeks (IG: 78.48±8.34 vs. CG: 76±13.26, p = 0.305) or at 34+0–36+4 weeks (IG: 73.25±10.27 vs CG: 73.45± 8.29,p = 0.920), and 50 gs glucose tolerance at 24+4–26+6weeks (IG: 116.23±35.07 vs CG: 116.36±25.98, p = 0.984); Aspartate-amino-transferase at 10+0–12+6 weeks (IG: 15.38±4.17 vs CG: 17.33±7.05, p = 0.124) and at 34+0–36+4 weeks (IG: 21.65±5.25 vs CG: 19.53±8.32, p = 0.165) or Alanine-amino- transferase at 10+0–12+6 weeks (IG: 27.50±10.63 vs CG: 28.27±11.77, p = 0.746) or at 34+0–36+4 weeks (IG: 22.93±9.23 vs CG: 20.84±13.49, p = 0.407); blood Creatinine concentrations at 34+0–36+4 weeks (IG: 0.595±0.401 vs CG: 0.575±0.100, p = 0.757) and blood uric acid concentrations at 34+0–36+4 weeks (IG: 3.526 ± 0.787 vs CG: 3.262±0.672, p = 0.218). Heart blood pressure was similar between groups except at 27+0–28+6 weeks, where systolic blood pressure was significantly lower in the CG in comparison to the IG (116.31±10.8 mmHg vs. 120.22 ± 10.3 mmHg, p = 0.010). Regular supervised exercise during pregnancy does not alter