When Are You Too Old for Pregnancy?

Late pregnancy is an option, but after age 40, you'll need both health and luck. And after 45, you'll need wealth, too.

Since women can't count on luck or wealth, those wanting to become pregnant should do so before age 45, argues Linda J. Heffner, MD, PhD, in the Nov. 4 issue of The New England Journal of Medicine.

Faced with career advancement or the dreaded "mommy track," more and more women are delaying pregnancy. First births to women aged 40 to 44 jumped 70 percent between 1991 and 2001, notes Heffner, professor and chairwoman of obstetrics and gynecology at Boston University.

"The great news is that if you are in the 35-45 age group and have not been in a position to have children -- if you do get pregnant and stay pregnant past the first trimester -- you have every reason to expect a good outcome," Heffner tells WebMD. "But the issue is that by your late 30s and early 40s, your ability to become pregnant is diminishing and your miscarriage risks are increasing."

Late Pregnancy: Modern Medicine vs. Age-Old Biology

When it comes to pregnancy, what does "late" mean? Women obviously are physically ready to have children in their teens. But in today's world, that's not always the best time for the woman or the child. There's a trade-off between when a woman's at her physical peak, and when it's the best social and psychological time for her to raise children.

"From a medical perspective, the safest time to have children is in the earlier part of your reproductive life," Heffner says. "And when education is an issue -- whether you intend to have a career or to provide that kind of environment for the children you will raise -- looking to your early to mid-20s is very reasonable. And for those with careers, that period between 25 and 35 is really ideal, all things considered."

Readers of celebrity magazines may be inspired by stories of movie stars in their late 40s having children. But the American Society for Reproductive Medicine recently issued a warning that most women can't expect to remain fertile that long.

Some women still don't understand that advice, says Richard J. Paulson, MD. Paulson is professor of obstetrics and gynecology and chief of the division of reproductive endocrinology and infertility at the University of Southern California Keck School of Medicine, Los Angeles. He's the author ofRewinding Your Biological Clock: Motherhood Late in Life: Options, Issues, and Emotions.

"Now I will still see a patient at age 45 who says, "You know, doctor, I am thinking of getting pregnant," Paulson tells WebMD. "She has no idea that the idea of a pregnancy with her own eggs is quite remote, even with in vitro techniques. Most of these women are menstruating, but nearly all are quite infertile. That is a relatively common misconception, that regular periods mean you are still fertile."

Even Heffner's good news for women age 35-45 should be qualified, says Alan H. DeCherney, MD, professor of obstetrics and gynecology and chief of the division of reproductive endocrinology and infertility at UCLA's David Geffen School of Medicine. DeCherney's 1982 NEJM editorial, "Female Fecundity and Age," foreshadows many of Heffner's current arguments.

"A woman's chance of becoming pregnant at age 35 to 40 is better than it is at age 40 to 45," DeCherney tells WebMD. "For young women, the longer they wait, there is a steady decline in fertility. But there is more to life than just getting pregnant. If a woman has a career and wants to delay pregnancy, she has an 85 percent chance everything is going to be great."

Late Pregnancy: How Late Is Too Late?

Heffner, Paulson, and DeCherney agree that by age 45, most women are no longer fertile.

"Past age 45, successful pregnancy requires health and wealth," Heffner says. "Of course there are some individuals who, at this age and older, retain their ability to become pregnant. But a lot of women don't. The great news is the biology is no longer totally limiting. But you have to keep in mind, if you are counting on that, that there still is an element of health -- and unfortunately, wealth. If you do, indeed, end up in a donor-egg program, it has to be paid for."

Health in this case means no heart disease, no diabetes, and no high blood pressure. Wealth means being able to pay for expensive procedures because few insurance programs cover the costs of egg donation. And Heffner notes that even among healthy women aged 45 and older, there is a high rate of pregnancy complications.

And there are, of course, psychological issues. Heffner warns in her editorial that couples who choose to have a baby in their late 40s must be prepared to face the issues surrounding their child's adolescence at the same time they face issues of their own retirement.

Paulson, however, says he's not too worried about the ability of older couples to understand what they're getting into.

"We've found this idea of raising children during a couple's older years to be not much of an issue," he says. "In many societies, grandparents do much of the child raising. And people who choose to become parents at 50 are smart and can make decisions for themselves. We trust 50-year-olds to be presidents and run the world. We can trust them to make decisions about their own future and how to spend the next 20 years. Yes, they know what it is like to raise children -- probably more than most 20-year-olds."

SOURCES: Heffner, L.J. The New England Journal of Medicine, Nov. 4, 2004; vol 351: pp 1927-1929. DeCherney, A.H. and Berkowitz, G.S. The New England Journal of Medicine, Feb. 18, 1982; vol 306: pp 424-426. Linda J. Heffner, MD, PhD, professor and chairwoman, obstetrics and gynecology, Boston University. Richard J. Paulson, professor, obstetrics and gynecology; chief, division of reproductive endocrinology and infertility, University of Southern California Keck School of Medicine, Los Angeles; author,Rewinding Your Biological Clock: Motherhood Late in Life: Options, Issues, and Emotions, W.H. Freeman & Co., 1998.Alan H. DeCherney, MD, professor, obstetrics and gynecology; chief, division of reproductive endocrinology and infertility, David Geffen School of Medicine, University of California, Los Angeles. American Society for Reproductive Medicine.

By Dan DeNoon, reviewed by Brunilda Nazario, MD