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) F2α and oxidative stress-derived F2-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 PGF2α later in pregnancy. Concentrations of 5 F2-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 PGF2α 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.