Changes in birth-weight of Hospital-delivered neonates in Addis Ababa

A retrospective study was conducted to establish recent birth-weight changes in singleton live births at Tikur Anbessa Teaching Hospital, Addis Ababa, Ethiopia for about 20 years period, September 1976 September 1996. The overall mean birth-weight was 3126g (SD=502). A decline in mean birth-weight was observed from 3162g (95% CI 3137-3186) and 3162g (95% CI 3149-3176) in the 70's and the 80's, respectively, to 3058g (95% CI 3041-3075) in the 90's. The over all proportion of low birth weight was 8.4%, increasing from 5.8% (95% CI 4.6%-7.3%) in the 70's to 7.1% (95% CI 6.4%-7.8%) in the 80's and to 11.3% (95% CI 10.2%-12.3%)in the 90's. When birth-weight was controlled for sex and maternal characteristics, a significant decrease on birth- weight was observed in the 90's, by about 81g (95% CI 44.3 - 118.5g) as compared to the 1970's. The odds of low birth-weight in the 90's was about 52% higher compared to the 70's: (OR=1.52, 95%CI=1.04-2.22). Similarly important changes in the distribution of pre-term delivery, maternal age, parity, sex ratio, and ante-natal follow-up that might have favored the decrease in birth weight were noted between the 90's and the earlier decades. Mean birth-weight was observed to peak in the months of August, September, and October ranging from 3143g to 3173g and fall between March and July. The proportion of low birth weight negatively correlated with the mean birth-weight was highest (10%) in April and observed to fall between August and October, with the lowest proportion of 6.2% in September. However, there was no considerable seasonal variation in birth-weight. In conclusion, the study has shown that mean birth-weight has declined in the 90's as compared to the earlier two decades and the proportion of low birth- weight increased in Addis Ababa, despite a continuing increase in the socioeconomic status. However, there was no considerable seasonal variation in birth- weight. (Ethiopian Journal of Health Development, 2000, 14(2): 169-176)