Association Between Maternal Prepregnancy Body Mass Index and Anthropometric Parameters, Blood Pressure, and Retinal Microvasculature in Children Age 4 to 6 Years
Authors: Bianca Cox, Leen J. Luyten, Yinthe Dockx, Eline Provost, Narjes Madhloum, Patrick De Boever, Kristof Y. Neven, Franco Sassi, Hanne Sleurs, Karen Vrijens, Paolo Vineis, Michelle Plusquin, Tim S. Nawrot
Journal: JAMA Network Open (2020)

<h3>Importance</h3> Maternal prepregnancy body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) has previously been associated with offspring cardiometabolic risk factors, such as fat mass, glucose and insulin levels, and blood pressure, but these associations appear to be largely mediated by offspring BMI. To our knowledge, no studies have assessed alterations in the retinal microvasculature in association with maternal prepregnancy BMI. <h3>Objective</h3> To investigate the association between maternal prepregnancy BMI and anthropometric parameters, blood pressure, and retinal vessel parameters in children age 4 to 6 years. <h3>Design, Setting, and Participants</h3> Participants included mother-child pairs of the population-based Environmental Influence on Early Aging (ENVIRONAGE) birth cohort study (Flanders, Belgium) who were recruited at birth from February 2010 to June 2014 and followed-up at age 4 to 6 years between October 2014 and July 2018. Data were analyzed from February 2019 to April 2019. <h3>Exposures</h3> Maternal prepregnancy BMI based on height and weight measurements at the first antenatal visit (weeks 7-9 of gestation). <h3>Main Outcomes and Measures</h3> Children's anthropometric, blood pressure, and retinal microcirculation measurements at age 4 to 6 years. Retinal vessel diameters and the tortuosity index, a measure for the curvature of the retinal vasculature, were obtained by fundus image analysis. <h3>Results</h3> This study included 240 mothers and children with a mean (SD) age of 29. 9 (4.2) years and 54.8 (4.7) months, respectively. Of these, 114 children (47.5%) were boys. Maternal prepregnancy BMI was positively associated with the child's birth weight, BMI, waist circumference, blood pressure, and retinal vessel tortuosity. A 1-point increase in maternal prepregnancy BMI was associated with a 0.26–mm Hg (95% CI, 0.08-0.44) higher mean arterial pressure for their children, with similar estimates for systolic and diastolic blood pressure. Independent from the association with blood pressure, a 1-point increase in maternal prepregnancy BMI was associated with a 0.40 (95% CI, 0.01-0.80) higher retinal tortuosity index (× 10<sup>3</sup>). The hypothesis that these associations reflect direct intrauterine mechanisms is supported by the following observations: associations were independent of the current child's BMI and the estimates for paternal BMI at the follow-up visit did not reach significance. <h3>Conclusions and Relevance</h3> Considering that blood pressure tracks from childhood into adulthood and microvascular changes may be early markers of cardiometabolic disease development, our results suggest that maternal prepregnancy BMI is an important modifiable risk factor for later-life cardiovascular health of the offspring.