One upside to having a baby later in life: Pregnant women in their 30s and 40s may have a lower risk of developing endometrial cancer, LiveScience reports. Scientists looked at data from 17 separate studies involving women with and without the cancer, which develops in the uterus' lining. They found women whose last pregnancy happened over age 40 were 44% less likely to get the disease than women who had her last child at 25 or younger. Those between 30 and 34 saw a benefit, but a reduced one: a 17% decreased risk. For those in the middle—35 to 39—the risk dropped by 32%.
It's not clear exactly why older pregnancies, which are usually linked to health risks for both mother and child, lower the risk of this specific type of cancer, but scientists have theories. Women who can get pregnant later in life may have naturally healthier uteruses, or giving birth may eliminate cancer-causing cells from the uterus; elevated hormone levels could help, too. But there's a cancer flip-side: Other studies have shown that giving birth to one's first child later in life can up ovarian and breast cancer risk.