Objective: To investigate the impact of advanced maternal age on the rate of perinatal mortality.
Design: Retrospective cohort study including all 56,517 singleton hospital deliveries between 1999 and 2008.
Methods: Data were analyzed according to maternal age at delivery in 3 groups of women, 25-34 years, 35-39 years and ≥ 40 years, using the youngest as the reference group.
Results: Odds ratios (ORs) for antenatal deaths were 0.98 (CI: 0.67-1.43) and 2.57 (CI: 1.57-4.22) for age groups 35-39 years and ≥ 40 years, respectively. Significant differences in neonatal mortality rates between the age groups were not found. Significant amendable risk factors were attendance of <4 health care visits (OR = 15.55, CI: 9.47-25.51 in age group 35-39 years; OR = 16.38, CI: 9.78-27.43 in the age group ≥ 40 years) and obesity (OR = 1.85, CI: 1.27-2.70 in age group 35-39 years; OR = 1.83, CI: 1.22-2.74 in the age group ≥ 40 years). In the multivariate regression analysis, the adjusted ORs for perinatal mortality were 1.03 (95% CI: 0.77-1.39) and 1.66 (95% CI: 1.03-2.66) for age groups 35-39 and ≥ 40, respectively.
Conclusions: Women older than 40 years carry an increased risk for stillbirth. Important amendable risk factors are obesity and poor antenatal care.