RESUMEN
To analyse the risk factors determining the frequency of small for gestational age [SGA] and appropriate for gestational age [AGA] low birth weight [LBW] babies in a secondary care neonatal unit. This analytic and observational study was carried out in Khyber Teaching Hospital Peshawar from 01-01-1999 to 31-12-1999. Singleton babies admitted into the neonatal unit with a birth weight <2.5 Kg were included. The data was statistically analysed for the independent effect of infant sex, maternal age, parity, socioeconomic status and material illness on the frequency of SGA and AGA LBW babies. Both SGA and AGA LBW groups, had a statistically significant association with mothers in age 21-30 years as compared to mothers with age /= 31 years [p<0.0001]. In both, SGA and AGA LBW groups, there was a statistically significant association with primiparous or multiparous mothers[p<0.0001] as compared to P2 mothers. Both groups had a statistically significant association with mothers in poor socioeconomic group as compared to mothers from middle and upper class [p<0.0001]. The association of poor socioeconomic group with SGA LBW group was significantly higher than the association with AGA LBW group [OR 1.8571, 95% CI 1.3131-2.6264, RR 1.16, p=0.0006]. Poor socioeconomic status is a significant independent risk factor, for the frequency of both SGA and AGA LBW babies in a developing country