Fig. 4
Distribution of pre-pregnancy body mass index and gestational weight gain. a Scatter plot shows the distribution of the mothers’ data for pre-pregnancy BMI and gestational weight gain. A smoothing line with locally estimated scatter plot smoothing is drawn in blue (confidence interval in gray). b Histogram of pre-pregnancy BMI. Blue lines indicate 17 and 23 kg/m2. c Density plots of gestational weight gain in each pre-pregnancy BMI category. d GWG differences among six groups classified according to pre-pregnancy BMI categories. e Differences in BW/GA percentiles among six groups classified according to pre-pregnancy BMI categories. Pre-pregnancy BMI categories: 17-18, 17 ≤ pre-pregnancy BMI < 18 (red) (n = 113); 18-19, 18 ≤ pre-pregnancy BMI < 19 (orange) (n = 233); 19 ≤ pre-pregnancy BMI < 20 (magenta) (n = 252); 20-21, 20 ≤ pre-pregnancy BMI < 21 (green) (n = 228); 21-22, 21 ≤ pre-pregnancy BMI < 22 (cyan) (n = 192); and 22-23, 22 ≤ pre-pregnancy BMI < 23 (blue) (n = 98). Box and whisker plots illustrate medians, minimums, maximums, and interquartile ranges. BMI, body mass index; BW/GA, birth weight for gestational age