In both developed and developing countries, birth weight is probably the single most important factor
that affects neonatal mortality, in addition to being a significant determinant of post-neonatal infant mortality and of infant and childhood morbidity (1).Thus, birth weight has long been a subject of clinical and epidemiological investigations and a target for public health intervention. In particular, considerable attention has been focused on the causal determinants of birth weight, and especially of low birth weight (LBW), in order to identify potentially modifiable factors.