How much does age affect fertility?
Women generally have some decrease in fertility starting in their early 30s. It is not unusual for a woman in her mid-30s or older to take longer to conceive than a younger woman. Age-related declines in fertility may be due, in part, to less frequent ovulation, or to problems such as endometriosis, in which tissue similar to that lining the uterus attaches to the ovaries or fallopian tubes and interferes with conception. If conception has not taken place after six months of trying, a woman over age 35 should consult her physician. Many cases of infertility can be treated successfully. While women over age 35 may have more difficulty conceiving, they also have a greater chance of bearing twins. The likelihood of naturally conceived (without fertility treatment) twins peaks between ages 35 and 39, then declines.
