Kitchen W H, Rickards A L, Ford G W, Doyle L W, Kelly E, Ryan M M
Department of Obstetrics and Gynaecology, University of Melbourne, Parkville, Australia.
Aust Paediatr J. 1989 Oct;25(5):288-91. doi: 10.1111/j.1440-1754.1989.tb01479.x.
The cognitive development at 2 and 5 years of a cohort of extremely low birthweight (ELBW) children (birthweight 500-999 g) was compared with that of cohorts of larger very low birthweight (VLBW) children (birthweight 1000-1500 g) and normal birthweight (NBW) children (birthweight greater than 2500 g) to determine whether the improvements in cognitive function of ELBW infants between 2 and 5 years are apparent or real. At 2 years of age, ELBW children had a mean Mental Developmental Index (MDI) on the Bayley Scales of 90.4, significantly lower than the means of 100.3 for the larger VLBW children (P = 0.006), and 107.8 for the NBW children (P = 0.0002). However by 5 years the mean scores on the Wechsler Preschool and Primary Scales of Intelligence (WPPSI) full-scale for the ELBW and larger VLBW children were virtually identical (105.9 and 106.0 respectively)--but still lower than the mean WPPSI full-scale of 114.6 for the NBW children. After standardizing the MDI and WPPSI scores relative to the NBW children, the ELBW children improved between 2 and 5 years (paired t-test, t = 3.2, P = 0.004) whereas the larger VLBW infants did not. We postulate that ELBW children require more time than larger VLBW children after birth to compensate for perinatal and other stresses, and that developmental delay at 2 years may not always persist to 5 years.
将一组极低出生体重（ELBW）儿童（出生体重500 - 999克）在2岁和5岁时的认知发展与较大的超低出生体重（VLBW）儿童（出生体重1000 - 1500克）和正常出生体重（NBW）儿童（出生体重超过2500克）的认知发展进行比较，以确定ELBW婴儿在2岁至5岁之间认知功能的改善是明显的还是真实的。在2岁时，ELBW儿童在贝利量表上的平均智力发展指数（MDI）为90.4，显著低于较大的VLBW儿童的平均值100.3（P = 0.006），以及NBW儿童的平均值107.8（P = 0.0002）。然而，到5岁时，ELBW和较大的VLBW儿童在韦氏学前及初小儿童智力量表（WPPSI）全量表上的平均得分几乎相同（分别为105.9和106.0）——但仍低于NBW儿童的WPPSI全量表平均得分114.6。在将MDI和WPPSI得分相对于NBW儿童进行标准化后，ELBW儿童在2岁至5岁之间有所改善（配对t检验，t = 3.2，P = 0.004），而较大的VLBW婴儿则没有。我们推测，ELBW儿童出生后比更大的VLBW儿童需要更多时间来补偿围产期和其他压力，并且2岁时的发育延迟可能并不总是持续到5岁。
