Apr. 7, 2010— -- For Marilyn Nolen, parenting came a little later in life than she expected. With the help of assisted reproductive therapy (ART) and donor eggs, she finally became the proud mother of twin boys -- when she was 55 years old.
Now 65 and raising her two rambunctious ten-year-olds in Killeen, Tex., Nolen is one of a growing number of women in the U.S. who have entered motherhood post-40.
While birth rates in 2008 dropped among women in their teens, twenties, and thirties, the 40-to-44 age bracket saw a 4 percent increase in birth rate, according to a report released Tuesday by the Centers for Disease Control and Prevention.
Birth rates increased for mothers over 45 as well, with the number of births among these women increasing by 4 percent in the past year. What's more, women over 40 were also more likely to be first-time mothers than in past years, the report found.
"This increase is part of a general trend that we've seen over the past few decades," says Brady Hamilton, lead author on the study and researcher for the CDC's National Center for Health Statistics. "A rise in reproductive technology gives women more options and more women are choosing to postpone childbirth or have a second or third child later in life," he says.
This doesn't mean it's easy to conceive in mid-life, however, warns Dr. Marjorie Greenfield, author of "The Working Woman Pregnancy Book" and director of general obstetrics and gynecology at University Hospitals Case Medical Center.
"Statistics like this encourage putting off pregnancy even more. It gives women the illusion that the biological clock doesn't really start ticking until later," she says, "but most births over 45 are from egg donors. The chance of getting pregnant without assisted reproductive therapy after age 40 is only 10 percent," she says.
Because of her age, Nolen wasn't able to use her own eggs. After nearly a decade of failed attempts with other fertility treatment, using in vitro fertilization with a donor egg and her husband's sperm was the only treatment that was finally successful.
High-Tech Pregnancies Increase Options
The rise in new and better reproductive technologies -- like those the Nolens used -- explains, in part, why more women are willing and able to conceive at middle age, Hamilton says.
"Assisted reproduction therapy and fertility treatments are feeding this trend," says Dr. Richard Paulson, chief of the division of reproductive endocrinology at the University of Southern California, "but it would be hard to tell how many people are actively waiting to have children [because they can use this technology] and how many are older women wanting to have children that now can because of an increasing social acceptance of being an older mother and this technology."
Nolen and her husband Randy would fall into the second category, older parents who would say "life just kind of played out this way." Nolen was already over 40 when the two got married, so while they both wanted children, the opportunity to start a family together came later in life. But that family didn't come easily.
"I was healthy and worked as a coach -- I thought it would just happen," Nolen says, "but when it didn't and I wasn't getting pregnant, we tried the regular fertility things [like] artificial insemination…without success. When I turned 50, we gave up and tried to adopt."
Two years and several failed adoption attempts later, the couple was accepted into a assisted reproduction therapy (ART) program run by Paulson after Randy found the fertility expert in a newspaper article. Three years after later, Nolen gave birth to her twin boys, Travis Steven and Ryan David.
"We really count our blessings that we happen to live when we did," Nolen says, remembering family members in past generations who were unable to have the families they so desperately wanted because of fertility issues.
"There are a variety of things about our society that push both men and women to delay childbearing -- professional achievement, becoming financially secure, what-have-you," says Paulson.
"What ART has done for women is to increase reproductive options and level the playing field a bit. That doesn't mean you should wait until 50 to be a mom, but if your life plays out in such a way that motherhood at an advanced age makes sense, it's nice to know that that option now exists."
Delayed Motherhood: Is 45 the New 35?
It's important to know, however, that this option can also come at a price.
By postponing pregnancy until middle age, women are at greater risk for gestational and birth complications that can affect both mother and child, notes Greenfield.
"By the time you're in your forties, you're more likely to go into the pregnancy with medical problems such as diabetes or hypertension, which can complicate the pregnancy. You are also at higher risk for getting gestational diabetes or hypertension during your pregnancy," she says. Nolen suffered from the latter of these two towards the end of her pregnancy, though she says she was lucky she had no serious complications.
Risk of genetic conditions like Down syndrome increase throughout the forties as well, but the most common issue women face when they try to conceive later -- one they often aren't expecting -- is miscarriage and infertility.
"When you see all these high profile women in their forties having children, women in their thirties think 'Great, I don't have to hurry.'" It's important to be aware that "this doesn't mean that you, individually, will be able to conceive later in life," Greenfield says.
ART can help battle dwindling fertility but the therapy doesn't always work and can itself complicate pregnancies because it makes women more likely to have multiple births.
"Twins confer more risks to pregnancy than any other thing we think of as high risk factors," Greenfield says, "and that's just twins, not triplets or other multiple births."
But if decreasing birth risk was the only consideration, all mothers would be 25, Paulson says, and clearly, there are many factors that feed into when a woman can or wants to conceive.
"Women's lives are complicated, and for some women it's just not feasible to have their children in their early thirties, when fertility is higher," Greenfield says.
Women are taking better care of themselves -- "Forty today doesn't look the same as 40 twenty years ago," she adds, "but that doesn't have anything to do with fertility."
Being young for your age "may affect how active you can be as a parent, but it doesn't help your fertility."