Andrej M Grjibovski¹, Lars Olov Bygren¹, Agneta Yngve¹, Michael Sjöström¹, and Yuri R Tedder². (1) Unit for Preventive Nutrition, Dept. of Biosciences at NOVUM, Karolinska Institutet, Hälsovägen 7, Huddinge, Sweden, +46-8-6083300, andrej.grjibovski@prevnut.ki.se, (2) Institute of Hygiene and Medical Ecology, Northern State Medical University, Troitski prospekt, 51, Arkhangelsk, Russia

Preterm birth is a leading cause of infant mortality in industrialized societies. It is associated with perinatal mortality, serious neonatal morbidity, and high health care expenditures. A large body of evidence suggests that preterm births are more frequent among socially disadvantaged women, although mediating factors may vary between the settings.

This study estimates the effect of maternal socio-demographic, obstetric, and lifestyle factors on the risk for spontaneous preterm birth in a Russian town.

All women with singleton pregnancies registered at antenatal clinics in a town of Severodvinsk comprised the cohort (n=1559). Analysis was based on spontaneous live births (n=1103). Multivariable logistic regression was applied to quantify the effect of the studied factors on the risk for preterm delivery. Differences in gestation duration were studied using multiple linear regression.

Altogether, 5.6% of all spontaneous births were preterm. Increased risks of preterm delivery were found in women with low levels of education (OR=8.5, [95% CI: 2.5-28.7] for women with basic education compared to women with university education) and in students (OR=2.5, 95% CI: 1.0-6.4). Placental complications (OR=11.4, 95% CI: 4.3-30.3), stress (OR=2.2, 95% CI: 1.2-3.8), and a history of foetal death (OR=6.2, 95% CI: 1.9-20.5) in previous pregnancies were also associated with elevated risks for preterm delivery. Smoking, hypertension, and multigravidity were associated with reduced duration of pregnancy in metric form.

In addition to medical risk factors, social factors are important determinants of preterm birth in transitional Russia. Large disparities in preterm birth rates may reflect the level of inequalities in Russia.

Learning Objectives: At the conclusion of the session, the participant in this session will be able to

• list the determinants of spontaneous preterm delivery,
• Discuss proximate factors, which may explain large social variations in preterm birth rates in Russia.

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.