Characteristics of study participants among 33-infant pairs according to maternal prepregnancy body mass index and gestational weight gain categories in Tianjin, China.

Large for gestational age was defined as birth weight >90th percentile; Small for gestational age was defined as birth weight <10th percentile.大于胎龄儿（Large for gestational age）被定义为出生体重大于第90百分位数；小于胎龄儿（Small for gestational age）被定义为出生体重小于第10百分位数。