Risk factors of pre-term birth in Bulgaria

Introduction: Prevalence of pre-term born children and newborns with low birth-weight under 2500 g. has been used as an important indicator for the assessment of population health. The low birth weight and pre-term birth are related to neonatal and infant mortality.
Aim: To assess the effect of certain risk factors - place of residence, mother’s age, marital status and employment on pre-term birth among the newborns delivered in the University Hospital in Pleven.
Methods: A case-control study was conducted among 1061 newborns delivered during the first half of 2007 in the Neonatal Ward of the University Hospital in Pleven. Information was extracted from the official hospital records using a questionnaire designed for the aim of this study. Parametric and nonparametric statistical methods (ANOVA, Chi-squared Pearson's test) were used for the analysis as well as multiple logistic regression modeling. Data were processed with SPSS v. 13.1.
Results: The rate of prematurely born children was 6.31%. The study found higher risk of pre-term birth for women in rural areas – adjusted OR=2.9; 95%CI [1,297 - 6,421] and unemployed mothers - OR=3.8; 95%CI [1,304 - 11,490]. The logistic regression model did not find maternal age to be an independent factor for pre-term birth in our study.
Conclusion: Several modifiable factors affect the risk of preterm birth. Women in rural areas and unemployed mothers are under higher risk of premature delivery. Health education and regular prenatal care must be provided to these risk groups.