Modern Maternity

There's no breakdown of how many of the childless women in that age group chose not to have kids and how many didn't have them because of fertility issues or other circumstances. But choice seems to be the operative word when it comes to how women feel about the lack of  children. Women without children who believed it was better to have a child were more likely to report being lonely and depressed in their later years than women who said it didn't make a difference, says Tanya Koropeckyj-Cox, associate professor of sociology at the University of Florida, author of a 2003 study that analyzed data from a survey of more than 3,800 men and women about relationships and family life.

Those women who do get pregnant after 40 may face a laundry list of age-related medical issues. "When you're older you tend to acquire diseases" such as high blood pressure and diabetes, both of which can affect pregnancies, says Dr. Alan Peaceman, chief of the division of maternal fetal medicine at Northwestern Memorial Hospital and professor of obstetrics-gynecology at Northwestern's Feinberg School of Medicine.

And simply being older and pregnant carries a much greater risk of miscarriage. Babies of older moms aren't immune to problems, either. They may be born too small or have underdeveloped lungs. And there is the risk for Down syndrome, which increases with maternal age, a problem that was in the spotlight recently when 44-year-old Alaska Gov. Sarah Palin, whose 5-month-old son Trig has the disorder, became the Republican nominee for vice president.

But "assuming they can get out of the first trimester without a miscarriage, most women can do fine," says Peaceman, who stresses that if women want to get pregnant later in life, it's important to protect fertility. That means quitting smoking, staying at a normal weight and avoiding sexually transmitted diseases.

The problems with later-in-life pregnancies are all too familiar to Terry Runyon, a 41-year-old banking executive from Chicago. Diagnosed with unexplained infertility in her mid-30s, Runyon underwent a series of assisted reproductive treatments. She got pregnant, but miscarried. Then she got pregnant again, and 17 weeks into the pregnancy, she lost one of the twins she was carrying. The surviving twin, Brandon, now 3, is healthy, happy and "completely the love of our lives," says Runyon.

And earlier this year, Runyon got a surprise. She's pregnant and due this October. "Everyone said I was infertile—and then I get pregnant just by having sex with my husband," she says. "I'm astounded."