Estonian medical birth registry 1992-1994: association of risk factors with perinatal mortality.

OBJECTIVE

To investigate the association of different maternal sociodemographic characteristics and infant sex with perinatal mortality among primiparas and multiparas.

STUDY DESIGN

Analysis of routine data from the Estonian Medical Birth Registry covering the whole of Estonia. A total of 47 358 infants (including stillborns) with a birth weight 1000 g or more from 1992 through 1994 were studied. Perinatal mortality rate, crude odds ratio (OR) and adjusted OR (calculated by a logistic regression model) were used to evaluate the association. OR values were adjusted for maternal age at delivery, maternal ethnicity, educational level, residence, marital status, smoking status, history of previous abortion and infant sex.

RESULTS

The perinatal mortality rate was 12.2 per 1000 total births among primiparous and 14.3 among multiparous women. The highest adjusted ORs of perinatal deaths were found in older (35 years and over) primiparas (1.78; 95% confidence interval (CI 0.88-3.57)) and multiparas (1.81; 95% CI 1.29-2.55), in unmarried (single) primiparas (1.59; 95% CI 1.14-2.20) and multiparas (1.98; 95% CI 1.29-3.05), in smoking primiparas (1.69; 95% CI 1.09-2.63) and multiparas (1.51; 95% CI 1.02-2.25), and in multiparas with unknown smoking status (1.98; 95% CI 1.18-3.33).

CONCLUSION

The study provides further evidence that perinatal mortality is positively associated with increased maternal age, unmarried (single) status and smoking.