1. Older maternal age and pregnancy outcome: a review of the literature;Hansen;Obstet Gynecol Surv,1986
2. Pregnancy in the older gravida: how old is old?;Hollander;Obstet Gynecol Surv,1990
3. Trends in multiple births conceived using assisted reproductive technology, United States, 1997-2000;Reynolds;Pediatrics,2003
4. Childbearing beyond maternal age 50 and fetal outcomes in the United States;Salihu;Obstet Gynecol,2003
5. Pregnancy-related mortality among women aged 35 years and older, United States, 1991-1997;Callaghan;Obstet Gynecol,2003