Curtis S. Harrod

Associations of maternal BMI and gestational weight gain with neonatal adiposity in the Healthy Start study

BACKGROUND Maternal obesity and weight gain during pregnancy are risk factors for child obesity. Associations may be attributable to causal effects of the intrauterine environment or genetic and postnatal environmental factors. OBJECTIVE We estimated associations of maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) overall and in early pregnancy, midpregnancy, and late pregnancy with neonatal adiposity. DESIGN Participants were 826 women enrolled in a Colorado prebirth cohort who delivered term infants (2010-2013). GWG to 39 wk of gestation was predicted by using mixed models, and early pregnancy, midpregnancy, and late pregnancy rates of GWG (0-17, 17-27, and 27 wk to delivery) were calculated from repeated weight measures. Neonatal body composition was measured by using air-displacement plethysmography ≤3 d after birth. RESULTS Each1-kg/m(2) increase in maternal BMI was associated with increased neonatal fat mass (5.2 g; 95% CI: 3.5, 6.9 g), fat-free mass (7.7 g; 95% CI: 4.5, 10.9 g), and percentage of body fat (0.12%; 95% CI: 0.08%, 0.16%). Each 0.1-kg/wk increase in predicted GWG was associated with increased fat mass (24.0 g; 95% CI: 17.4, 30.5 g), fat-free mass (34.0 g; 95% CI: 21.4, 46.6 g), and percentage of body fat (0.55%; 95% CI: 0.37%, 0.72%). No interaction was detected between BMI and GWG in their effects on neonatal body composition. Early pregnancy, midpregnancy, and late pregnancy rates of GWG were independently associated with fat mass and percentage of body fat. Midpregnancy and late pregnancy GWGs were associated with fat-free mass. An observed GWG that exceeded recommendations was associated with higher neonatal fat mass and fat-free mass but not percentage of body fat relative to adequate GWG. CONCLUSIONS Maternal prepregnancy BMI and GWG, including period-specific GWG, were positively and independently associated with neonatal adiposity. Associations of early and midpregnancy weight gain with neonatal adiposity support the hypothesis that greater maternal weight gain during pregnancy, regardless of prepregnancy BMI, is directly related to offspring adiposity at birth. The Healthy Start study was registered as an observational study at clinicaltrials.gov as NCT02273297.

Physical activity in pregnancy and neonatal body composition: the Healthy Start study.

OBJECTIVE: To examine associations between pregnancy physical activity and neonatal fat mass and fat-free mass, birth weight, and small for gestational age (SGA). METHODS: We analyzed 826 mother–neonate pairs (term births) participating in the longitudinal Healthy Start study. The Pregnancy Physical Activity Questionnaire was used to assess total energy expenditure and meeting American College of Obstetricians and Gynecologists (College) guidelines for physical activity during early pregnancy, midpregnancy, and late pregnancy. Models were adjusted for maternal and neonatal characteristics. RESULTS: Neonates had mean fat mass of 292.9 g, fat-free mass of 2,849.8 g, and birth weight of 3,290.7 g. We observed 107 (12.9%) SGA and 30 (3.6%) large-for-gestational age neonates. A significant inverse linear trend between total energy expenditure during late pregnancy and neonatal fat mass (Ptrend=.04) was detected. Neonates of mothers in the highest compared with the lowest quartile of total energy expenditure during late pregnancy had 41.1 g less fat mass (249.4 compared with 290.5 g; P=.03). No significant trend was found with total energy expenditure and neonatal fat-free mass or birth weight. Early-pregnancy and midpregnancy total energy expenditure were not associated with neonatal outcomes. No significant trend was observed between late-pregnancy total energy expenditure and SGA (Ptrend=.07), but neonates of mothers in the highest compared with the lowest quartile had a 3.0 (95% confidence interval 1.4–6.7) higher likelihood of SGA. Meeting the College’s physical activity guidelines during pregnancy was not associated with differences in neonatal outcomes. CONCLUSION: Increasing levels of late-pregnancy total energy expenditure are associated with decreased neonatal adiposity without significantly reduced neonatal fat-free mass. LEVEL OF EVIDENCE: II

Maternal Fuels and Metabolic Measures During Pregnancy and Neonatal Body Composition: The Healthy Start Study

CONTEXT The impact of specific maternal fuels and metabolic measures during early and late gestation on neonatal body composition is not well defined. OBJECTIVE To determine how circulating maternal glucose, lipids, and insulin resistance in the first and second halves of pregnancy influence neonatal body composition. DESIGN A prospective pre-birth cohort enrolling pregnant women, the Healthy Start Study, was conducted, in which fasting maternal serum samples were collected twice during pregnancy to measure glucose, insulin, hemoglobin A1c, triglyceride, total cholesterol, high-density lipoprotein, and free fatty acids. Neonatal body composition was measured with air displacement plethysmography. SETTING An observational epidemiology study of pregnant women attending obstetric clinics at the University of Colorado, Anschutz Medical Center. PARTICIPANTS This analysis includes 804 maternal-neonate pairs. RESULTS A strong positive linear relationship between maternal estimated insulin resistance (homeostasis model of assessment for insulin resistance) in the first half of pregnancy and neonatal fat mass (FM) and FM percentage (FM%) was detected, independent of prepregnancy body mass index (BMI). In the second half of pregnancy, positive linear relationships between maternal glucose levels and offspring FM and FM% were observed, independent of prepregnancy BMI. An inverse relationship was detected between high-density lipoprotein in the first half of pregnancy and FM, independent of prepregnancy BMI. Free fatty acid levels in the second half of pregnancy were positively associated with higher birth weight, independent of prepregnancy BMI. CONCLUSION Maternal insulin resistance in the first half of pregnancy is highly predictive of neonatal FM%, whereas maternal glycemia, even within the normal range, is an important driver of neonatal adiposity in later pregnancy, independent of prepregnancy BMI. Our data provide additional insights on potential maternal factors responsible for fetal fat accretion and early development of adiposity.

Role of developmental overnutrition in pediatric obesity and type 2 diabetes

Childhood obesity continues to be a significant public health burden. Empirical evidence has begun to identify intrauterine and postnatal pathways that increase the likelihood of excess adiposity and increased risk of type 2 diabetes among offspring. Reviewed here is the evidence supporting a transgenerational vicious cycle that increases obesity and diabetes in offspring and contributes substantially to the increases in obesity and type 2 diabetes observed over the past several decades. The public health impact of these findings is discussed and future research opportunities are outlined.

Exposure to prenatal smoking and early-life body composition: the healthy start study.

To examine associations between exposure to prenatal smoking and early‐life changes in fat mass (FM), fat‐free mass (FFM), and anthropometrics.

Childhood Obesity Is There Effective Treatment

Though rates appear to have recently pla-teaued in some US demographic subgroups, including non-Hispanic white individuals and those of higher socioeco-nomic status, stark racial and ethnic disparities are stillevident as the prevalence of obesity among Hispanic andAfrican American children is nearly twice that of non-Hispanicwhitechildren.