At what age may a woman stop conceiving, naturally?

Menopause. As long as a women is ovulating, she could potentially conceive. However as she ages, her fertility will decrease due to the age of her eggs. Generally, fertility is considered to be decreasing by age 37, and is rapidly declining by age 40. When menopause occurs, conceiving naturally is no longer possible. The average age for menopause is 50 to 52, but any time after age 40 is considered normal.