General characteristics of the study population (n = 2972)*.

Yrs: years; cm: centimeters; g: grams; BMI: body mass index; kg: kilograms; m: meters.*Data were missing for parity (n = 3), smoking during pregnancy (n = 201), breast feeding at 2 mo (n = 237) breast-feeding duration (n = 564), siblings (n = 974), day-care attendance at 12 mo (n = 617), day-care attendance at 24 mo (n = 591), maternal height (n = 3), paternal height (n = 434), BMI 2 months (n = 359), BMI 6 months (n = 132), BMI 14 (n = 295), BMI 25 months (n = 549), height 2 months (n = 359), height 6 months (n = 192), height 14 months (n = 293), height 25 months (n = 545).¶P values for trend are derived from x2 test for trend (categorical factors) or for the linear trend test of the 1-way analysis of variance.