Maternal fitness at the onset of the second trimester of pregnancy: correlates and relationship with infant birth weight

摘要

Background: It is still unclear whether maternal physical activity and fitness during pregnancy contributes to perinatal health. Objectives: The aims of this study were to characterize maternal physical fitness at 16 weeks of pregnancy and to examine its effects on infant birth weight. Methods: Maternal anthropometry (body mass index [BMI] and skin-folds), physical activity, cardiorespi-ratory fitness (VO_2peak) and muscular fitness (handgrip strength) were assessed at 16 weeks of gestation in 65 healthy pregnant women. Offspring birth weight was collected from maternal charts after delivery. Results: A higher VO2peak was associated with physical activity spent at sports and exercise before and in early pregnancy (P = 0.0005). Maternal BMI was negatively associated with cardiorespiratory fitness (P< 0.0001) but positively related to muscular strength (P = 0.0001). Unlike maternal cardiorespiratory fitness, handgrip strength was positively associated with infant birth weight (r = 0.34, P = 0.0068) even after adjustment for confounders (adjusted r = 0.27, P = 0.0480). Conclusion: A positive relationship between maternal muscular fitness and infant birth weight highlighted maternal strength in pregnancy as a new determinant of infant birth weight.