小于胎龄儿 (smallforgestationalage ,SGA)是指出生体重在同胎龄平均体重的第 10百分位以下或低于平均体重 2s的新生儿。国外报道其发生率为 5 % ,在我国发病率约为5 %～ 15 % ,生后常有体格发育落后。一般认为SGA生后发生身材矮小的风险为出生身材正常儿的 5～ 7倍。SGA的本 Smaller than gestational age (SGA) refers to newborns whose birth weight is below the 10th percentile of the mean gestational age or below 2 s of mean body weight. Foreign reports of its incidence of 5%, the incidence in China is about 5% to 15%, often after birth physical development is lagging behind. It is generally believed that the risk of short stature after SGA is 5 to 7 times of normal body weight of birth. SGA’s this