A woman's peak reproductive years are between the late teens and late 20s. By age 30, fertility (the ability to get pregnant) starts to decline. This decline becomes more rapid once you reach your mid-30s. By 45, fertility has declined so much that getting pregnant naturally is unlikely for most women.
Women do not remain fertile until menopause. The average age for menopause is 51, but most women become unable to have a successful pregnancy sometime in their mid-40s. These percentages are true for natural conception as well as conception using fertility treatment, including in vitro fertilization (IVF).
What age does a woman stop being fertile?