Pregnancy Exercise Mode Effect on Childhood Obesity

Many public health initiatives in the United States, including Healthy People 2020, have goals that include reducing obesity (OB), metabolic dysfunction, and risk of cardiovascular disease (CVD). Studies such as the Bogalusa project have now demonstrated that overweightness (OW), beginning as early as age five, is predictive of adult CVD. In fact, the onset of OW/OB and CVD may begin in the intrauterine period, and infant birth weight and weight gain are strongly related to OB in childhood and beyond. OW/OB mothers and their offspring exhibit increased morbidity and mortality; the American College of Obstetricians and Gynecologists (ACOG) has developed guidelines geared toward reducing maternal OW/OB through exercise. However, few studies have focused on how such exercise interventions during pregnancy impact short and long-term child health outcomes. Furthermore, little is known regarding the influence of different modes of antenatal exercise upon maternal and offspring health outcomes.

The long-term goal of this study is to attenuate child- and adulthood OB and CVD risk by identifying the most effective and easily implemented maternal exercise interventions. The investigators have shown that maternal aerobic exercise (AE) in women of all BMIs favorably impacts maternal cholesterol and LDL levels, which are predictive of infant weight. Furthermore, maternal AE is associated with decreased fetal abdominal circumference (AC), lower body fat percentage at one month, and improved infant neuromotor skills. Our preliminary data for pregnant women of all BMIs suggests that resistance exercise (RE) confers similar benefits to infants at one month as compared to AE, plus improvements such as decreased BMI z-scores, increased metabolomic signatures for glucose use, and decreased metabolites of inflammatory pathways. The most striking finding from this preliminary work is that adding RE to AE improved outcomes for both mothers and infants. Thus, the COMBINATION of aerobic and resistance exercise (AERE) not only had better maternal and one month infant outcomes (versus AE alone), but AERE groups had the best compliance. The positive changes were most pronounced in the infants of OW/OB women. A more comprehensive, longitudinal study geared toward OW/OB mothers is needed to confirm our preliminary work and to assess the persistence of exercise impacts through the infants' first year of life.

The overall objective of this proposal is to conduct a longitudinal prospective study of OW/OB pregnant women and their offspring to determine which antenatal maternal exercise mode(s) will have the greatest impact on maternal and infant cardiometabolic health. This information may lead to modified clinical practice recommendations that improve health in childhood and possibly beyond. This randomized controlled trial will recruit 284 OW/OB pregnant women randomized to an exercise intervention (AE, RE, AERE) or to no exercise (usual care); their infants will be measured at 1, 6, and 12 months of age. This rigorous design will test our central hypothesis that AERE and RE exercise training during pregnancy will, in OW/OB women, improve maternal and offspring cardiometabolic outcomes to a greater extent than AE alone. The investigators will test this hypothesis with two specific aims:

Aim 1. Determine the influence of different exercise modes during OW/OB pregnancy on infant cardiometabolic health and growth trajectories. Hypothesis: AE, RE, and AERE by OW/OB pregnant women will improve offspring neuromotor and cardiometabolic measures at 1, 6, and 12 months postpartum (e.g. decreased BMI z-score, body fat %, non-HDL, heart rate, and C-Reactive Protein (CRP); increased insulin sensitivity) compared to infants of OW/OB pregnant women that do not exercise; AERE and RE will have the greatest impact on improving infant measures.

Aim 2. Determine the most effective exercise mode in OW/OB pregnancy on improving maternal cardiometabolic health outcomes. Hypothesis: AE, RE, and AERE by OW/OB pregnant women will improve both maternal cardiometabolic health measures (e.g. decreased BMI z-score, body fat %, HR, non-HDL, weight gain) across pregnancy (~13 to ~40 weeks gestation) and overall pregnancy outcomes (e.g. lower incidence of gestational diabetes, pre-eclampsia, hypertension during gestation) compared to OW/OB pregnant women that do not exercise; AERE and RE will have the greatest impact on improving maternal health measures, with the AERE group having the highest compliance with improved health outcomes.

The proposed innovative study will be the first to provide a critical understanding of the influence of antenatal exercise modes upon the cardiometabolic health and growth trajectories of offspring who are at increased risk due to maternal OW/OB. This work will have a significant impact on reducing the cycle of OB and CVD, potentially providing the earliest and most efficacious intervention to attenuate or prevent OB and CVD in the next generation.