Physical fitness is associated with prostaglandin F2α isomers during pregnancy

Introduction: Pregnancy and physical activity are associated with oxidative stress and immune changes. We hypothesized that pregnant women physically more active in early pregnancy will display a better oxidative stress management and inflammatory response later in pregnancy compared with less active pregnant women. Material and methods: Maternal physical activity using accelerometry monitors for 1 week and cardiorespiratory fitness (VO2 at anaerobic threshold) were assessed at 14-18 weeks in 58 pregnant women. Plasma and erythrocytes membrane samples were obtained from maternal blood samples at 14-18 and 34-37 weeks of pregnancy. Pro-inflammatory prostaglandin (PG) F-2 alpha and oxidative stress-derived F-2-isoprostanes were measured by high-performance liquid chromatography coupled to tandem mass spectrometry. Results: Higher physical activity levels at 14-18 weeks measured by mean counts per minute, >30 min/d of moderate to vigorous activity or >6500 steps/d at 14-18 weeks of pregnancy were associated with lower levels of total plasmatic PGF(2 alpha) later in pregnancy. Concentrations of 5 F-2-isomers in erythrocyte membranes in late pregnancy were significantly higher in the third (17.5-19.5 mL kg(-1) min(-1)) and/or fourth (19.6-27.7 mL kg(-1) min(-1)) quartiles of cardio-respiratory fitness compared to the first quartile (13.9-15.9 mL kg(-1) min(-1)). Conclusions: Overall, higher cardio-respiratory fitness in early pregnancy is associated with enhanced erythrocyte membranes oxidation at 34-37 weeks reflecting a higher oxygen transfer capacity. Also, the most active women experienced lower circulating levels of pro-inflammatory PGF(2 alpha) in plasma at 34-37 weeks, a marker associated with adverse antenatal inflammation-associated conditions. These results support the practice of physical activity by pregnant women.