Advanced maternal age and the risk of perinatal death due to intrapartum anoxia at term.

BACKGROUND Advanced maternal age is associated with higher risks of intrapartum complications. However, the effect of maternal age on the risk of perinatal death due to these complications is unclear. The aim of the present study was to determine the association between maternal age and delivery-related perinatal death at term. METHODS In this retrospective cohort study, birth records of 1,043,002 singleton term infants with cephalic presentation were analysed excluding anomalous and antepartum losses in Scotland between 1985 and 2004. Linked Scottish national registries of pregnancy outcome data and perinatal death data were used. The event was delivery-related perinatal death (ie, intrauterine fetal death during labour or death of the infant in the first 4 weeks of life), plus a subgroup ascribed to intrapartum anoxia. RESULTS There were 803 delivery-related perinatal deaths, with 490 due to intrapartum anoxia (4.7 per 10,000 births) and 313 (3.0 per 10,000 births) due to non-anoxic causes. Compared to women aged 25-34, women aged 40 and above had a twofold risk of delivery-related perinatal death at term (adjusted OR 2.20, 95% CI 1.42 to 3.40). The excess was explained by increased risk of death due to intrapartum anoxia. Among women in labour at term, age greater than 40 was independently associated with risk of anoxic death among primiparous (adjusted OR 5.34, 95% CI 2.34 to 12.20) and multiparous women (adjusted OR 2.14, 95% CI 0.99 to 4.60). CONCLUSIONS Advanced maternal age is associated with an increased risk of death due to intrapartum anoxia at term.