Secular trends in pregnancy outcomes in 1980-1999 in the Komi Republic, Russia

Objectives. To describe secular trends in selected pregnancy outcomes in the Komi Republic, Russia, in 1980-1999. Study design. A descriptive study. Methods. Data on all single infants born in Syktyvkar and Vorkuta during the period 1980-1999 were abstracted from the birth journals at maternity homes (n=69,340). Proportions of stillbirths, preterm and post-term births as well as the mean values for birth weight and length of term infants were estimated in each of the locations over time and summarized in 5-year periods. Multiple logistic and linear regression analyses were used to study independent effects of the time periods on the outcomes, adjusted for maternal age in Syktyvkar and for maternal age, parity and infant gender in Vorkuta. Results. Considerable variations over time were observed for all studied outcomes except for stillbirths. The lowest prevalence of both preterm and post-term births was observed in 19851999 in both Syktyvkar (4.3% and 3.2%) and Vorkuta (3.5% and 3.1%). Average birth weight in term infants was significantly lower in 1.995-1999 in both Syktyvkar (-33 g, 95% CI: -46,-21) and Vorkuta (81 g, 95% CI: -100, -62) than in 1980-1984. Conclusions. The proportions of preterm and post-term births increased while the average birth weight in term infants decreased over the 20-year period of observation. Further research should address those factors that could explain the observed pattern of pregnancy outcomes in the Komi Republic.