Another 25 premature infants with study group matched gestational age, weight, and Apgar score, who had been previously treated at this NICU from 1990 to 1992 served as control group.
Another 25 premature infants with study group matched gestational age, weight, and Apgar score, who had been previously treated at this NICU from 1990 to 1992 served as control group.
另外1990年至1992年随机取样25位怀孕周数、出生体重和实验组一样的早産儿爲对照组。