The likelihood of twins peaks between ages 35 and 39, then declines. The risk of bearing a child with certain chromosomal disorders increases as a woman ages. The most common of these disorders is Down syndrome. About 95 percent of women who undergo prenatal testing receive the reassuring news that their baby does not have one of these disorders. If prenatal testing rules out chromosomal defects and the mother is healthy, the baby is at no greater risk of birth defects than if the mother were in her 20s.
Most miscarriages occur in the first trimester for women of all ages.
The rate of miscarriage in older women is significantly greater than that of younger women. Though women in their mid-30s and older are no more likely to have a stillborn or premature baby than women in their 20s, older mothers may have more problems along the way. Women over 35 are at increased risk of placental problems and bleeding during pregnancy, and are more likely to have low-birthweight babies than women in their 20s. Have a pre-pregnancy medical checkup and obtain early and regular prenatal care during pregnancy. Eat a variety of nutritious foods, and achieve proper weight for height before conception.