Timing and Magnitude of Peak Body Mass Index and Peak Weight Velocity in Infancy Predict Body Mass Index at 2 Years in a Retrospective Cohort of Electronic Health Record Data

Objectives To use growth data from electronic health records to describe and model infant growth (weight velocity and peak body mass index [pBMI]) characteristics. Study design We extracted data from all children born at >= 34 weeks of gestation within one health system be-tween 2014 and 2017. After excluding implausible growth data with an algorithm created for childhood growth, we estimated pBMI, peak weight and length velocities, and the odds of obesity at 2 years, adjusted for race, sex, ethnicity, and birth weight, by the magnitude of peak weight velocity, peak length velocity, and pBMI. Results Among 6425 children (41% White, 28% Black, 26% other race; 16% Hispanic ethnicity), mean pBMI was 17.9 kg/m(2) (SD 1.5) and mean age at pBMI was 9.6 months (SD 2.7). Mean peak weight velocity was 949 g (SD 165) per 2 weeks, and the mean peak length velocity was 3.4 cm (SD 0.3) per 2 weeks. Children with obesity at 2 years (n = 931, 14.5%) were more likely to be Hispanic, had greater peak weight and peak length velocities, and had 2 kg/m(2) greater magnitude of pBMI than children without obesity. For each unit increase in pBMI, children had more than 4 times greater odds of obesity at age 2 years. Conclusions In a large sample of infants with clinical growth data tracked via electronic health records, we found associations between the magnitude and timing of peak infant BMI and obesity at 2 years of age.