Maternal Exercise and DHA Levels During Pregnancy Influences Infant Body Composition

Abstract

Nearly 14% of U.S. children aged 2-5 years are obese. Evidence indicates that obesity develops in utero and is affected by several maternal factors. Maternal exercise is shown to reduce the risk of delivering high-birthweight infants. However, previous studies restricted their exercise exposure to aerobic training; thus, the effects of other common exercise modes on infant body composition are unknown. Maternal diet, specifically DHA levels, is also suspected to affect infant size. Maternal DHA is shown to improve infant birth weight and decrease fat mass. However, it is unclear as to whether this association is affected among exercising mothers. PURPOSE: To determine the relationships between different maternal exercise modes and maternal plasma levels of DHA on infant body composition. METHODS: Thirty-six healthy, low-risk, women with a singleton pregnancy (<16 weeks) were randomized to one of four intervention groups: aerobic (n=13), resistance (n=4), circuit (n=6)(aerobic + resistance) or non-exercising control (n=13) group. Participants exercised 3x/week for 50 minutes at moderate intensity for ~20 weeks. Maternal plasma was collected at 16 and 36 weeks of gestation and analyzed for DHA levels using liquid chromatography/mass spectrometry. At one month of age, infant body composition was assessed via skinfold technique. ANCOVA models were performed to determine independent associations between maternal exercise mode, maternal DHA levels, and infant percent body fat (%BF). RESULTS: Infants born to aerobic- or circuit-trained mothers had significantly lower %BF compared to infants born to resistance-trained mothers (p=0.045, p=0.048), respectively. After controlling for infant sex, 16-week maternal DHA levels, and fasted state, maternal exercise exhibited no effect on infant %BF (F, 0.57; p=0.6865). Maternal DHA levels at 16 weeks (F, 1.30; p=0.2887), 36 weeks (F, 1.13; p=0.3742) or across pregnancy (~20 weeks) (F, 1.27; p=0.3026) did not associate with infant %BF, after controlling for maternal exercise mode, sex, and fasted state. CONCLUSION: The current data supports the relationship between maternal exercise modes with aerobic activity on infant body composition. The data suggests that exercise mode may be a more important modulator of infant body composition than maternal DHA levels.