Infant lung function and physical activity in pregnancy

Abstract

<b>Background and aim:</b> Physical activity (PA) in pregnancy is important for maternal and possibly offspring’s health. To study early origins of lung function we explored if physical inactivity in the first half of pregnancy was associated with lower lung function in healthy 3-month-old infants. <b>Methods:</b> From the general population-based PreventADALL birth cohort recruiting infants antenatally in Norway and Sweden, all 814 infants (48.8% girls) with available Tidal Flow Volume measures in the awake state at three months of age and mid-pregnancy PA data were included. Based on self-reported moderate or high intensity PA, we categorized maternal PA level as inactive, fairly or highly active. The main outcome was the ratio time to Peak Tidal Expiratory Flow to Expiratory time (<i>t</i>_PTEF/<i>t</i>_E), secondarily dichotomized into <i>t</i>_PTEF/<i>t</i>_E&nbsp;&lt;0.25, or below the 10^th, 25^th or 50^th percentile. Associations were analyzed by linear regression, adjusting for maternal age, education, parity, pre-pregnancy BMI, nicotine exposure and parental atopy. <b>Results:</b> The overall mean (SD) <i>t</i>_PTEF/<i>t</i>_E was 0.391 (0.08), lowest in the 290 infants of inactive mothers, 0.387 (0.09), highest in those of 299 highly active mothers, 0.394 (0.08), p=0.59. Although <i>t</i>_PTEF/<i>t</i>_E as a continuum was not significantly associated with maternal PA, infants of inactive compared with active mothers had higher odds of having a <i>t</i>_PTEF/<i>t</i>_E &lt;0.25, by univariable (OR 2.15, 95% CI [1.19, 3.92], p=0.011) and multivariable (OR 2.18, 95% CI [1.18, 4.06], p=0.013) regression. <b>Conclusion:</b> Lower lung function, by <i>t</i>_PTEF/<i>t</i>_E &lt;0.25, was more frequent in infants of inactive versus physically active mothers, while no overall significant association between PA in the first half of pregnancy and infant <i>t</i>_PTEF/<i>t</i>_E was found.