OBJECTIVE The purpose of this study was to evaluate pregnancy outcome in women at extremely advanced maternal age (≥ 45 years). METHODS We compared the condition of women aged ≥ 45 years (n = 177) in a 10:1 ratio (20-29, 30-39, and 40-44 years.). Subgroup analysis compared the condition of women aged 45-49 years with those women aged ≥ 50 years. RESULTS The rates of gestational diabetes mellitus and hypertensive complications were higher for the study group, compared with the whole group (17.0% vs 5.6% and 19.7% vs 4.5%, respectively; P < .001), as was the rate of preterm delivery at <37 and <34 weeks of gestation (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.2-3.6 and OR, 3.5; 95% CI, 1.4-9.0, respectively). The rates of cesarean delivery (OR, 31.8; 95% CI, 18.0-56.1), placenta previa, postpartum hemorrhage, and adverse neonatal outcome were significantly higher among the study group. The risk for gestational diabetes mellitus, preeclampsia toxemia, preterm delivery, and neonatal intensive care unit admission was increased for women aged ≥ 50 years. CONCLUSIONS Pregnancy at extreme advanced maternal age is associated with increased maternal and fetal risk.