Contribution of maternal age, medical and obstetric history to maternal and perinatal morbidity/mortality for women aged 35 or older.

For women aged ≥35 years, presence of medical conditions conferred a greater risk for morbidity/mortality than age itself. For multiparous women, the effects of medical and obstetric history were additive. The contribution of maternal age to adverse outcomes in pregnancies without significant medical and obstetric history is modest.