Association of maternal smoking during pregnancy with aerobic fitness of offspring in young adulthood: a prospective cohort study.

Abstract

We evaluated the association of maternal pre-pregnancy body mass index (BMI), gestational weight gain (GWG), and maternal smoking with aerobic fitness in young men aged 19-20years. A 19-year prospective cohort study. Data from the Northern Finland Birth Cohort 1986 (NFBC1986) and the Sodankylä Jaeger Brigade, Finland, in 2005-6. Mothers and the 508 offspring in the NFBC1986 who entered military service at the Sodankylä Jaeger Brigade in 2005. Associations of weight, 12-minute running test (Cooper test), and muscle fitness index (MFI) of offspring on entry to military service were evaluated with antenatal factors, including maternal smoking, pre-pregnancy BMI, and GWG. Aerobic and muscle fitness of the offspring were evaluated by the Cooper test and MFI. Maternal smoking during pregnancy was associated with lower aerobic fitness of male adolescents, measured by the Cooper test (2356m; 95% confidence interval, 95% CI 2265-2446m), compared with the offspring of mothers who did not smoke during pregnancy (2537m, 95% CI 2499-2574m). This association was independent of the BMIs of both the mother and the offspring, GWG, and the smoking and physical activity of offspring (regression coefficient -140.6m, 95%CI -273.1 to -8.0m). High maternal pre-pregnancy BMI and excessive GWG were also associated with lower aerobic fitness of the offspring; however, this association was mediated via the weight of the offspring. Maternal smoking during pregnancy may have a negative impact on the aerobic fitness of the offspring. Study shows that young men have lower aerobic fitness if their mothers smoked during pregnancy.