Socioeconomic determinants of preterm birth: a prospective multicenter hospital-based cohort study among a sample of Kazakhstan.

Background: Preterm birth (PTB) is the most stubborn cause of neonatal morbidity and mortality globally. Social determinants are one of the predictors of health disparities and conflicting when regarding the etiology of PTB. The current study objected to investigate the impact of the factors especially from socioeconomic aspects and provided a snapshot of the indicators of PTB in Kazakhstan.

Material and methods: A multi-center hospital-based cohort study was conducted on 3,000 singleton pregnant women in Kazakhstan to investigate whether socioeconomic status (SES) influences PTB in Kazakhstan. The study involved clinical data collection and structured questionnaires covering socioeconomic status, health behaviors, and obstetric history, with a final sample of 2,235 women successfully followed through to delivery. The social, demographic, and other health-related determinants for preterm birth were analyzed using bivariate and multivariate statistical methods. The associations between factors and PTB were evaluated by chi-squared tests in bivariate analysis. Independent variables with p < 0.1 in the bivariate analysis were included in a logistic regression model.

Result: History of PTB in previous pregnancies, maternal body mass index, housing stability, history of teen pregnancy, parity and general health status of mother were associated with PTB in bivariate analysis. In the logistic regression model, variabls significantly associated with PTB included a history of previous preterm birth, history of teen pregnancy, lower pre-gestational body mass index, primiparity and poorer maternal general health status. Additionally, the significance of the variables varied among the different subtypes of PTB heterogeneity. Women who were divorced, widowed and separated (OR = 5.1; 95% CI: 1.9-13.7) and those who pregnant for first time (OR = 3.8; 95% CI: 1.9-7.7), those with gestational diabetes (OR = 5.2; 95% CI: 1.7-16.3) had increased risk of extremely and very preterm birth, respectively. Women with a low body mass index (OR = 2.3; 95% CI: 1.3-3.9) and those with a history of teen pregnancy (OR = 0.4; 95% CI: 0.2-0.7) had increased risk of moderate to late preterm.

Conclusion: These results contribute to a better understanding of PTB predictors in Kazakhstan and highlight the need for comprehensive maternal care strategies to improve pregnancy outcomes.