predictors of low birth weight infants in the north west province of iran: a case-control study

background: ninety-five percent of low birth weight infants are born in developing countries. this study was aimed to assess the predictors of low birth in east azerbaijan, north-west province of iran. materials and methods: the study was conducted through a hospital based case–control design involving 49 women delivering low birth weight infants and 98 delivering normal weight infants. the data analysis was using spss-13 software with bivariate and multivariate methods. results: there was a significant positive association between maternal chronological and marriage ages with low birth weight infants (p <0.05). additionally, there was negative association between maternal weight prior to pregnancy and low birth weight (p <0.05). interestingly, larger families of more than four members had higher probability for low birth weight infants in comparison to the families with less than four members (or = 2.86, 95% ci: 1.09-7.47; p-value: 0.032). according to the multivariate logistic regression independent factors associated with low birth weight include higher maternal chronological age (or = 1.88, 95% ci: 1.29 - 2.75; p-value: 0.001) and marriage age (or = 4.97, 95% ci: 1.97 - 12.50; p-value: 0.001) and increase in maternal weight prior to pregnancy (or = 0.60, 95% ci: 0.42 - 0.86; p-value: 0.006). conclusion: major risk predictors of low birth weight in the iranian female population were maternal age other than 25-30 at delivery, young maternal marriage age and lower maternal weight before pregnancy.