Optimizing Pregnancy for Intergenerational Health Benefits

Abstract

A mong the many factors that contribute to childhood obesity (i.e. maternal smoking, nutrition/sugar intake, air pollution, endocrine disruptors, sleep disturbance, lack of breastfeeding), there are two powerful maternal determinants: high maternal body mass index (BMI) and exceeding the Institute of Medicine (IOM) gestational weight gain (GWG) guidelines [1]. Furthermore, pregnancy weight-related issues increase the likelihood of adverse cardiovascular risk factors in offspring [2,3]. Excessive GWG is directly linked to giving birth to a large-for-gestational-age (LGA) neonate [4], which is predictive of downstream obesity and chronic conditions, including Type 2 diabetes and cardiovascular disease [reviewed in 5,6]. Recently, high birth weight and parental overweight/obesity were associated with lower levels of both physical activity (PA) and cardiorespiratory fitness in adolescence [7], further supporting the need for prenatal strategies that optimize fetal growth for long-term health. To the surprise of many, excessive GWG in normal-weight women is associated with higher neonatal fat mass and less favorable body composition (i.e. greater percentage of body fat, less muscle mass) [8]. This dysregulation in body composition suggests that an energy surplus in utero acts independent of parental genetics with respect to predisposition for excess weight. In fact, according to recent systematic reviews and meta-analyses, excessive GWG increases the risk of childhood overweight/obesity by 30-40% [9,10], thereby propagating the intergenerational cycle of obesity and the proliferation of chronic disease [5]. This may be due to a host of sociopolitical and physiological factors that promote maternal resource storage, decrements in PA, a loss of metabolic control, and a partitioning of excess energy reserves to the fetus [5,11].Physical activity remains one of nature's best medicines for prevention and management of chronic disease [12]. However, it is seldom recommended in pregnancy [13]. Furthermore, population PA levels are at an all-time low [14] and reach a nadir during the prenatal period. The reasons for these observations are not well-established, but likely involve a patient-provider knowledge translation discrepancy [15]. Despite the historical dogma and the ensuing clinical recommendations, a pregnant Keywords: Pregnancy; Physical activity; Pediatrics; Obstetrics; Exercise Pregnancy is a critical period of body weight regulation for both mother and baby. Vital energy-sensing processes are established in utero that aid in nutrient storage and metabolic control later in life. Excessive weight gain during pregnancy and a surplus of maternal resources leads to preferential shuttling of nutrients and growth-promoting peptides across the placenta, resulting in fetal overgrowth -a well-established predictor of childhood obesity. Physical activity during pregnancy offers a safe and accessible way in which one can modify these intricate cellular networks across the maternal-placental-fetal interface to prevent dysregu...