Figure 2.

Relative trajectories of organ size via ultrasound vs age by feeding group. (a) Uterine volume in girls (soy formula vs cow-milk formula, P = 0.01; soy formula vs breast milk, P < 0.01; breast milk vs cow-milk formula, P = 0.07). (b) Breast-bud diameter in girls (soy formula vs cow-milk formula, P = 0.72; soy formula vs breast milk, P = 0.73; breast milk vs cow-milk formula, P = 0.92). (c) Breast-bud diameter in boys (soy formula vs cow-milk formula, P = 0.37; soy formula vs breast milk, P = 0.02; breast milk vs cow-milk formula, P = 0.05). Feeding-group–specific trajectories fitted to data were shifted vertically to a common intercept at a log₂-transformed value of zero (dashed line) to better display postnatal changes (i.e., fitted log₂-transformed organ size at a given age minus fitted log₂-transformed organ size at birth). Thus, the vertical axis represents the ratio of current size to size at birth. Shaded bands represent 95% pointwise confidence limits for each feeding-group–specific trajectory. Absolute trajectories (i.e., those without vertical shift to common intercept) are shown in Supplemental Fig. 3.