ccording to World Health Organizati

ccording to World Health Organization, low birth weight
(LBW) is defined as weight at birth less than 2500g (UNICEF
and WHO, 2004). The two major causes of LBW are
prematurity (born before 37 weeks of gestation) and
intrauterine growth retardation (a condition in which fetal
growth has been constrained) (Kelley and Pojda, 2000; Nohr
et al., 2008).
Each year, over 20 million infants are born with LBW
worldwide, resulting in a LBW rate of 15.5% (UNICEF and
WHO, 2004).
The risk of neonatal death for infants who have LBW,
weighing 2000–2499g at birth is estimated to be four times
higher than infants weighing 2500–2999g, and ten times
higher than for infants weighing 3000–3499g (Ashworth,
1998).