normal intrauterine growth depends on genetic potential and is influenced by hormonal and environmental factors , including maternal nutrition and health . small for gestational age ( sga ) refers to an infant born with a weight or length , two standard deviations ( sds ) below the mean for his / her gestational age . in 2010 , an estimated 324 million infants were born sga in low- and middle - income countries ( 27% of live births ) , of whom 106 million infants were born at term and low birth weight ( lbw ) . the prevalence of term - sga babies ranged from 53% of live births in east asia to 415% in south asia . the incidence of lbw in india is about 30% babies in contrast to 57% in developed countries . impaired fetal growth can be caused by a number of fetal ( genetic abnormality , congenital defects etc . ) maternal ( disease condition , nutrition , drug use ) , and demographic ( socioeconomic status , maternal age , obstetric history ) factors . it is related to an increased risk of perinatal morbidity and mortality , developmental disabilities , and a tendency to reduced postnatal growth with final short stature . those who experience rapid catch - up growth are at risk of developing metabolic syndrome whereas those without catch - up may end up with short stature . . growth and maturity of children is a sensitive index of health which can be influenced by many factors . however , studies suggest that very lbw children are often shorter than expected even after correction for gestational age . studies evaluating the effect of birth weight on growth of children report that birth weight is a significant marker of delayed growth and short stature . studies reveal that a large number of socioeconomic variables are associated with the physical development of children . these variables consist of parental profession , income , education , birth order , urbanization , etc . about 90% of sga children show some degree of accelerated growth during infancy that can be viewed as a compensatory mechanism for prenatal growth deficit , referred to as  catch - up growth . while 80% of infants born sga show catch - up growth during the first 6 months of life , 90% have catch - up growth with a height sd score of more than 2 by 2 years of age . approximately , 10% do not show catch - up growth , and most of these children continue to experience poor growth throughout childhood and remain short after the age of 2 years . these individuals constitute a relatively high proportion of children and adults with short stature with a relative risk of 57 times than children born at normal size . thus , the aims of this study were to assess the growth of children born sga between two socioeconomic strata in comparison with age- and sex - matched healthy controls and assess factors associated with growth in sga children . this retrospective study was based on data retrieved from two hospitals in pune city , maharashtra , india ( one catering to a lower socioeconomic class population and other to patients from upper socioeconomic class ) , from july 2012 to july 2014 . a total of 618 children of age range between 0.5 and 5 years were enrolled randomly from all 800 available records . 2 for their gestational age were included in the study ( sga ) ; for comparison of healthy controls were also selected . to compare growth in these sga children across socioeconomic strata , data were selected from both lower and upper socioeconomic strata ( uss ) . a total 189 sga children from uss , 217 sga from lower socioeconomic strata ( lss ) , and 212 appropriate for gestational age healthy controls detailed birth history , maternal history ( mode of delivery , presence of diabetes or hypertension ) , maternal anthropometry ( height , weight ) , socioeconomic status , and anthropometry ( length / height and weight ) of the children were recorded . anthropometric data were converted to z scores ; height for age z scores , and weight for age z scores ( haz , waz ) using who anthroplus software . differences between two groups were tested by using t - test and between three groups were tested using one - way anova . categorical variables were analyzed using the chi - square test and fisher exact test when indicated . for controlling confounding variables , in this retrospective study , data were collected on a total 618 children ( boys 52.9% ) . children from both lower as well as uss were selected so as to study the growth pattern between the two groups . around 65.5% children were from lss and 34.5% belonged to the uss . of the total children selected , 34.3% were of normal birth weight ( weight > 2500 g ) and rest of the 65.7% ( 50.3% lbw and 15.4% very lbw ) were lbw ( birth weight < 2500 g ) as per the standard definition . data analyses were performed between the three groups : children born sga from lss and from uss and healthy controls . mean ages of all 3 groups were similar ( 2.6 years for uss , 2.8 for lss , and 2.9 for controls ) ( p > 0.1 ) . the haz and waz of the sga group were significantly lower as compared to the controls ( p < 0.05 ) and that of the lss sgas were lower than that of the uss sgas ( p < 0.05 ) . however , other factors such as body mass index and mid parental height were not significantly different among the groups . target height z scores were significantly lower for lss sgas in comparison to uss sgas and healthy controls ( p < 0.05 ) [ table 1 ] . figure 1 illustrates the percentage of children who were stunted ( haz < 2.0 ) in each group . stunting was observed in 32% children in uss and 49% children in lss ( p < 0.05 for all ) . percentage of stunted children   normal height ( > 2.0 height for age z - score )   stunted ( 2.0 height for age z - score ) furthermore , when the percentage of stunted children was computed age - wise , it was noted that in the uss sga group , 29% of children were stunted at 2 years and at 5 years , 17% were stunted whereas in the lss sga group , 54% of children were found to be stunted at 2 years and 46% at 5 years . hence , there was a discrepancy in catch - up growth between lss and uss children [ figure 2 ] . percentage of stunted children in upper socioeconomic strata and lss at the age of 2 years and 5 years   2 years   5 years to determine factors associated with stunting in sga children , generalized linear model ( glm ) was used . factors such as socioeconomic status , gestational diabetes , pregnancy induced hypertension , birth weight of children , neonatal events , breast feeding months , episodes of illness in children , maternal age , and mid parental height were considered as independent predictors for predicting stunting in children . glm analysis revealed that children from lss had 1.1 ( 0.91.1 ) times greater risk of stunting than children from uss ( p < 0.1 ) . children with lbws had 1.3 ( 1.21.4 ) times greater risk of stunting and those with very lbws had 1.7 ( 1.41.8 ) times greater risk of stunting than controls ( p < 0.001 ) . children who suffered from moderate to severe major illnesses had a 1.1 ( 1.01.1 ) times greater risk of stunting as compared to children who did not suffer from any major illnesses ( p < 0.1 ) . glm also revealed that mother 's age was positively associated with the risk of stunting (  = 1.009 ( 1.01.01 ) ( p < 0.05 ) . however , other factors such as gestational diabetes , pregnancy induced hypertension , neonatal events , and mid parental height were not correlated with stunting in children ( p > 0.1 ) . present study results revealed that the sga group children were stunted as compared to the controls ; higher percentages of children from the lss , who were sga , were stunted as compared to the uss . further , there was a discrepancy in catch - up growth between lss and uss children with higher percentage of the lss children being stunted at 5 years . socioeconomic status and birth weight ( especially very lbw ) influenced the variation in children 's height . the other significant predictors for stunting in sga children also included severe illness episodes and maternal age . maternal factors in pregnancy such as inadequate diet , intrauterine infection , and inflammation are the major determinants of lbw babies and sga babies . from epidemiological studies , it is apparent that suboptimal breastfeeding and complementary feeding practices , recurrent infections , and micronutrient deficiencies are important proximal determinants of stunting . however , in the present study , we did not find any association between breastfeeding and stunting . linear growth failure also occurs within a complex interplay of more distal community and societal factors , such as access to healthcare and education , urbanization , population density , and social support networks , which have been captured in the who conceptual framework on childhood stunting , as recently reviewed . the major factor for stunting which was observed in our sga children was economic status . since socioeconomic and nutritional problems as well as preventable diseases are key contributors to lbw in developing countries , it is very important to assess the effect of socioeconomic status on growth in sga infants , which may be compromised . along with socioeconomic status , education of parents had direct effect on growth . finding from silva et al . study revealed that both socioeconomic status and birth weight were significantly correlated with stature whereas the sex of children , maternal age , size of family , and ordinal position of the child in the family were not related . our findings are in agreement with this study and have identified lbw and socioeconomic status as significant determinants of stunting in children . in a cross - census study from brazil , prevalence of stunting was 10.9% , which was higher for children whose mothers had 04 years of schooling , 13.3% were poorer , 14.8% had more than one child younger than 5 years at home . both the studies portray socioeconomic inequalities and lack of access to basic health care and social assistance . the unassisted children from these regions become vulnerable in their full development , as persistent nutritional deficiencies in childhood impair weight initially and then slow growth , finally affecting height , thus ; socioeconomic level was associated as an important risk factor for stunting . studies have shown that repeated or prolonged episodes of diarrhea during childhood increases the risk of stunting ; neonatal morbidity is thus a significant risk factor for poor growth in children . though we could not establish any association of stunting with maternal education in present study , the findings pertaining to economic class and illness in childhood are in accordance with the above studies . other variable that had significant effect on stunting in our study was maternal age . it is well known that children born to adolescent mothers are vulnerable to infant mortality and poor health outcome . showed that children born to mothers who were married below the age of 18 were at a higher risk of stunting and underweight compared to children of women who had married at age 18 or older . another similar study enunciated that after controlling for maternal , paternal , and household and social factors , there was an improvement in child health outcomes ( linear growth and weight ) as the age of the mother at first birth increases to age 2729 years . nutritional catch - up patterns normally vary substantially across socioeconomic groups ; rural study from ethiopia found that average catch - up growth in height - for - age is almost perfect among children in relatively better - off households whereas among the poorer children , relative growth failure is more persistent . household wealth , and in particular access to services , can lead to substantial catch - up growth early on in life . in a large prospective british cohort study , results show a graded association between birth weight and height at each of the follow - up examinations between ages 7 and 23 months with greater catch - up growth in upper social class . our results are on par with this where catch - up growth was more in higher economic class . researchers have broadly mentioned two possibilities for greater  catching up  in growth in lbw infants born to higher socioeconomic class . first , environmental influences associated with social class affecting growth in the fetus as well as during childhood . another explanation is that the higher social condition has a favorable effect on the growth of lbw infants because of education , nutritional supplements , and health care . hence , the growth retardation in small for gestational age babies can be overcome by improved social conditions and proper health care from childhood to adulthood . we recommend that better socioeconomic condition can improve stature of children and can prevent the hazardous effect of high risk factors . on the other hand , there were certain limitations in the present study , there was no data available on diet history and history of illness otherwise the correlation of these social factors also would have been studied for stunting risk . children born sga showed relatively poor growth and stature as compared to healthy controls ; sga children from the lss , very lbw babies and those with major illnesses during early years of life are at a greater risk for growth deficit .