Social variations in infant growth performance in Severodvinsk, Northwest Russia: community-based cohort study

To examine infant growth characteristics and their socio-demographic determinants in Severodvinsk, northwest Russia.

Length-for-age, weight-for-age, and weight-for-length Z-scores of 1,067 infants born in 1999-2000 in Severodvinsk were calculated on the basis of the data on the length and weight obtained from the medical files. Multiple linear regression was used to estimate independent effects of maternal age, education, occupation, marital status, weight, parity, sex of the baby, and breastfeeding duration on infant growth.

At the age of 12 months, 1.1% of the infants were stunted, 1.1% underweight, and 0.5% wasted in comparison with the Centers for Disease Control and Prevention 2000 reference population. The mean Z-scores for length-for-age, weight-for-age, and weight-for-length were 0.48+/-0.93, 0.38+/-1.04, and 0.65+/-1.03, respectively. Mean weight-for-length Z-scores considerably increased from birth to 12 months, while length-for-age Z-score remained largely unchanged. In regression analysis, length-for-age Z-scores were lower by 0.43 (p=0.028) and by 0.30 (p<0.001) in infants born to mothers with basic and unknown education, respectively. Positive trends between linear growth and maternal age (p=0.027) and education (p=0.024) were observed. No social variations in weight-for-length Z-scores were found.

Prevalence of stunting, underweight, and wasting were lower than previously reported from Russia, which may reflect good overall socio-economic conditions in the town. Social variations in linear growth indicate the existence of inequalities in infant health, which may further increase with age.