Socio-demographic determinants of birth weight and ponderal index in an urban Russian setting

Abstract

Background: There is much evidence from epidemiological studies of a link between poor realization of genetic growth potential in utero and elevated risk of some adult diseases. The associations between low birth weight and infant mortality and morbidity are also well established. The fetal growth determinants vary in different settings, and there is still a need for analysis within environments. Aim of the study: This research was designed to describe the social circumstances of pregnant women and to examine the relation between measures of fetal growth [birth weight and ponderal index (PI)] and socio-demographic factors, smoking and alcohol consumption in a Russian setting. Methods: All pregnant women registered in prenatal care centers from 1 January to 31 December 1999 in a town of Severodvinsk (north-west Russia) comprised the cohort (n = 1,559) and were followed through delivery. Data on maternal and infant characteristics were obtained from the medical records and a questionnaire. After excluding women who had abortions (n = 77), stillbirths (n = 5), delivered twins (n = 11) and were lost to follow up(n = 67), the analysis was based on the remaining 1,399 women who delivered live singleton infants at the municipal maternity home. Multivariate linear regression was applied to quantify the effect of the studied variables on birth weight and the PI with and without adjustment for potential confounders. Adjustment for gestational age was made to separate the effect of the studied factors on fetal growth from the length of gestation. Results: Reduced birth weight was associated with maternal secondary education (-137 g; 95% CI: -217; -57), unemployed status of the partner (-130 g; 95% CI: -202; -59), maternal smoking (-126 g; 95% CI: -198; -54), primiparity (-97 g; 95% CI: -256; -37), poor housing conditions (-89 g; 95% CI: -153; -25 and -82 g; 95% CI: -136; -28 for living in shared apartments and crowded housing respectively), and perceived stress (-61 g; 95% CI: - 116; -7) compared to the reference groups. Living with parents (142 g; 95% 25; 259), male sex of the infant (122 g; 95% CI: 80; 165), being 30 34 years old (100 g; 95% CI: 23; 176), and, surprisingly, occasional alcohol consumption (65 g; 95% CI: 2; 129) were positively related to birth weight after adjustment for confounding factors.