2、 Birth weight(出生体重) normal birth weight 2500-3999g low birth weight(LB W): <2500g very low birth weight(VLBw) <1500g extremely low birth weight(ELBW): 1000g macrosomia ≥4000克２、Birth weight (出生体重) normal birth weight： 2500-3999g low birth weight(LBW): <2500g very low birth weight(VLBW): <1500g extremely low birth weight(ELBW): < 1000g macrosomia：  4000克 N I CU