When Rachel P., after an early marriage and divorce, remarried in her late 30s, she and her new husband didn’t plan on children. But, over time, the couple began to yearn for a baby. When they didn’t conceive naturally, Rachel underwent a round of fertility treatments at Duke’s Reproductive Endocrinology & Infertility Center. Two years later, with the help of eggs from a 22-year-old donor, she finally became a mother.

Now 45, Rachel has her hands full: in addition to mothering her daughter, Caroline -- now an energetic toddler -- she’s coping with perimenopause. “Most days go by in a sort of blur,” Rachel admits. “But, even with my hectic life and hot flashes, I wouldn’t trade Caroline for anything.”

While total births in the United States have decreased in recent decades, they have risen sharply among older women. Today, one in every 12 babies is born to women aged 35 and older. The reasons are varied: women are healthier and living longer than ever before. And between careers and late marriages, they sometimes don’t get around to contemplating motherhood until many other women their age have school-aged children.

The first concern for any woman contemplating motherhood later than usual, of course, is fertility. “Women are born with their full complement of eggs and, unfortunately, cannot make new ones,” says David K. Walmer, MD, PhD, chief of Duke's reproductive endocrinology and fertility division. “Because a woman’s eggs age as she does, her ability to conceive drops drastically after her mid 30s. By age 40, about 65 percent of women are unable to conceive naturally.”

As more and more women seek to have babies later, an increasing number turn to fertility treatments. More than 40,000 babies were born in the U.S. as a result of assistant reproductive technology (ART) procedures in 2001.

“Although we encourage women to seek conception at a younger age if possible, older women who want to become mothers still have excellent options,” says Walmer. While success rates for fertility drugs and in vitro fertilization are lower for older prospective mothers, Walmer points out that donated eggs can significantly boost the odds of a viable pregnancy: “When eggs from young women in their 20s are used, pregnancy rates are over 50 percent, even if the recipient is in her 40s.”

When an older woman does conceive with her own eggs, risks to both mother and child are slightly higher. The incidence of Down syndrome and other chromosomal defects that can cause mental retardation increase with age, but are extremely low even in older women. Women who deliver babies after age 40 also have higher rates of gestational diabetes, high blood pressure, premature births, and Cesarean sections.

Walmer suggests a full medical evaluation before you get pregnant, genetic counseling, and regular follow-up care during and after pregnancy to help manage these and other health concerns.

A woman who has postponed motherhood looks forward to showering her child with all the unconditional love that she has been saving up for decades. But that rosy dream of motherhood can meet a rude awakening when the fatigue that typically accompanies new motherhood is combined with perimenopausal hormone fluctuations.

“Postpartum depression can seem worse to older women, because there has been so much riding on this pregnancy and birth,” says Duke’s Diana Dell, MD, who is both an OB/GYN and a psychiatrist. “Sleep deprivation is a big issue in postpartum depression, especially for older women, who don’t have the reserves of energy that younger mothers do. The rapid decline of hormones that follows childbirth can lead to especially intense mood swings at midlife.”

Yet -- despite the obvious challenges -- midlife motherhood can offer unique rewards and growth opportunities. “Though our bodies are designed to have babies at a younger age, many women have the opportunity to become mothers in a more balanced and healthy way when they’re further along in their lives,” says Tracy Gaudet, MD, an OB/GYN who is director of Duke’s Center for Integrative Medicine.

“Because of the physical and hormonal changes during pregnancy, it’s good to prepare yourself as best you can, as you would if you were running a race,” Gaudet adds. “You really need to optimize your health. Take a serious look at your nutrition -- for example, make sure to get plenty of folic acid and Omega-3 fatty acids. Enhancing your fitness level can not only ease the physical symptoms, but help you manage postpartum depression.

All that said, Gaudet says, it’s equally important that you don’t try to be a superwoman. “Some women have babies in their 40s and then go straight into menopause,” she says. “So you need to start by recognizing that you’re basically going through two major transitions at once. Don’t just try to plow straight through it. The best thing you can do is acknowledge that and try to address it as fully as you can.”