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 between 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/m2 (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/m2 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.