Last updated: Feb 04, 2014
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When Michal Rubin began trying for her second child at age 37, she figured it would be a breeze: "I had gotten pregnant with my son Koby two years earlier, soon after going off the pill," says Rubin, now 45. It wasn't. Within 18 months, the former ad exec, who lives in Stamford, Conn., had had two miscarriages. Rubin saw an infertility specialist, eventually conceiving her daughter, Nava, via in vitro fertilization (IVF)—in which sperm fertilizes an egg in a petri dish and the resulting embryo is placed in the uterus. She didn't bother going back on birth control after Nava was born. Nine months later, she was stunned to learn that she was pregnant. "For two days," says Rubin, whose third, Lev, is now 3, "my husband and I couldn't look at each other without laughing or crying."


There are few issues more confounding to a woman today than Will I be able to get pregnant when and if I want to? On one hand, we've all seen news reports and headlines warning us that our ability to conceive is waning by the day. On the other, we can't leaf through a celebrity glossy without seeing spreads of women like Halle Berry and Nancy Grace expectant well into their 40s. Even the experts concede that it's still a mystery why some women get pregnant effortlessly and others struggle. "We have hints—factors like when your mom went through menopause and how regular your cycles are—but they don't tell us everything," says Sarah Berga, MD, chair of ob-gyn and women's health at Wake Forest Baptist Medical Center in Winston-Salem, N.C. "So much of it depends on the individual."

Bottom line: Yes, it is possible to have a baby after age 35—a welcome message for women whose life circumstances didn't line up neatly with an earlier conception date. And if it turns out that you are unable to conceive on your own, there are now more ways than ever before to become pregnant with medical help.

Your eggs: A primer

As you may remember from middle-school health class: Every month, several cysts called follicles begin to develop in our ovaries, along with the eggs that reside inside them. Of those eggs, just one will fully mature and be released during ovulation. Women are born with all the eggs they'll ever have, and of the approximately 1 million we hold at birth, only about 300 are ever released. The rest degenerate, so you're down to about 25,000 by around age 37; by your early 50s, you've got a measly 1,000. That may still sound like a lot, but "the older you are, the greater the chances that eggs have been damaged by the aging process or by environmental factors, like smoking," Dr. Berga says. Damaged eggs are more prone to having chromosomal abnormalities, which is why about a third of all pregnancies in women age 35 to 45 end in miscarriage.

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Yes, age affects fertility...

In all the chatter about biological clocks, one idea seems to stand out: Women believe that after 35, their chances of getting pregnant fall precipitously. And yet there's no real basis for that belief. True, fertility does decline with age. But it's not an immediate dive. "If you look at a curve of women who have fertility problems, it's slightly higher at 37 than it is at 36 than it is at 35," says Lauren Streicher, MD, an ob-gyn at Northwestern University Medical Center and author of Love Sex Again. "You don't see a sharp drop until about age 40."

"For many women, fertility can be maintained through the age of 37," agrees William Gibbons, MD, a fertility specialist with the Family Fertility Center at Texas Children's Pavilion for Women in Houston. "We just don't know who these women are until they try to get pregnant for a year."

In fact, more women are getting pregnant in their late 30s than we think. A study published last June found that while women around age 30 had the highest rates of conception (and that's without factoring in lifestyle habits), 72 percent of women between age 35 and 40 were pregnant within a year of trying, compared with 87 percent of women age 30 to 34 and 83 percent of women age 25 to 29. "The older women may have been technically less fertile, but they had fairly high pregnancy rates because they were trying harder to get pregnant," says study author Lauren Wise, ScD, an epidemiologist at Boston University.

And as other heartening research suggests, if you effortlessly get pregnant once, it may be easy the second time, too, though it's unclear whether that's due to your natural fertility or your lifestyle choices. While 47 percent of married women age 40 to 44 have difficulty getting pregnant, according to the Centers for Disease Control and Prevention (CDC), only 7 percent of women who've already given birth have trouble at that age.

Wise has found similar results: Women with kids had approximately the same fertility rates at age 40 as they did at age 20, while fertility decline became more pronounced at around age 34 in childless women. "I've long believed that a successful pregnancy might kick your ovaries into gear for future pregnancies," she says. "Or, if a woman is easily able to get pregnant once, she may naturally be more fertile than average." On the flip side, a woman who makes it to her late 30s without ever getting pregnant or even having a scare could simply be less fertile. She may also have had habits like smoking or conditions like STDs that would have lowered her chances all along, suggests Anjani Chandra, PhD, a CDC health scientist. Indeed, "the woman who comes to me at age 38 because she can't get pregnant may very well have had issues at 28," says Harry Lieman, MD, medical director of Montefiore's Institute for Reproductive Medicine and Health in Hartsdale, N.Y.

Plus, real women share their fertility stories.

...But there's more to the story

So why did Michal Rubin have such trouble conceiving her second child? The reality is, age is only one of many variables that influence fertility. High stress levels can be an obstacle (that's what Rubin blames for her issues), as can certain conditions: Some studies show that up to half of all infertility patients suffer from endometriosis, and 10 percent from fibroids. Other situations that can signal problems:

Your mom went through early menopause "But if she went through it in her 50s as opposed to her 40s, you probably will, too, meaning you should stay fertile for longer," Dr. Streicher says. "Just don't count on that."

Your period is irregular "This could mean you're not ovulating, possibly because you're starting to creep into perimenopause," says Pamela Berens, MD, professor of ob-gyn at the University of Texas in Houston.

Your cycles are short Women whose menstrual cycles run shorter than 25 days are 35 percent less likely to conceive than women whose cycles are 27 to 29 days long, Wise's research has shown. "Generally, short cycles involve a narrower fertile window," she explains, "which seems to be linked with a lower probability of conception."

Looking into your fertility future

Beyond all these factors, recent scientific advances have yielded promising tests that can help you get a better sense of your reproductive potential.

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The newest is the anti-Müllerian hormone (AMH) test, which you can have done at your ob-gyn's office at any time during your cycle. "Released by your follicles, the hormone declines along with your egg pool," Dr. Streicher says. A number above 0.5 nanograms per milliliter indicates you have adequate egg reserves. Still, "the test doesn't measure egg quality, which is an issue—I've had patients with high ovarian reserves who can't get pregnant," notes Mary Jane Minkin, MD, an ob-gyn at the Yale University School of Medicine. Then there are ultrasounds to measure your antral follicle count, which shows how many follicles are starting to develop each cycle. "Less than six per ovary may be a sign that you've got fewer eggs than other women your age," Dr. Lieman says. Again, though, ultrasounds don't tell you how good those eggs are.

The fallibility of these tests raises the question: Who should undergo them? "Let's say you have a 35-year-old woman, with no partner and no interest in having a baby at that moment, who simply wants to know her fertility status," Dr. Lieman says. "I don't advocate that—you could drive yourself crazy with that knowledge if you're not prepared to act on it yet." Other docs disagree. "If a 37-year-old woman walks into my office with regular cycles, I'm probably going to tell her that testing isn't needed," Dr. Berens says. "But if she has irregular cycles or has a disorder like polycystic ovary syndrome [PCOS] that could affect her fertility, then I think she should consider testing."

If the results show low ovarian reserve, that's reason to think about getting pregnant soon—or freezing your eggs or embryos for insurance. Several studies have found that you have about the same likelihood of getting pregnant using a fertilized frozen egg as with a fertilized fresh egg. "If you freeze your eggs at age 30 and use them at age 40, you should have the same success rates as if you'd tried a decade earlier," says Jamie Grifo, MD, director of the NYU Fertility Center in New York City. "By the late 30s or early 40s, egg quality is waning, and freezing isn't as effective."

Egg freezing is pricey; the cost can run upwards of $20,000 and is usually not covered by insurance. In 2013, the American College of Obstetricians and Gynecologists stated that while it recommends oocyte cryopreservation (as it's technically called) to patients who are infertile due to chemotherapy or other treatments, there's not enough data yet to show that it's advisable for healthy women trying to extend their reproductive years. Even so, 96 percent of women in a 2013 study who froze their eggs said they'd do it again—even if they'd never used them.

Say you've undergone IVF or an intrauterine insemination (IUI)—a procedure that places sperm inside the uterus—and your eggs don't cooperate. You can then try donor eggs. Since most donors are in their mid- to late 20s, you're likely to be as successful at conceiving as women in that age range. "Those pregnant celebs over age 44 are most likely using them," Dr. Grifo says. It's not just the rich and famous who are doing it, either. The number of donor egg cycles performed in the United States increased from almost 11,000 in 2000 to a little more than 18,000 in 2010, according to an Emory University study published in October. About a quarter of these cycles led to the birth of a healthy, full-term infant.

Try and try again

"Every year, we learn a little bit more about fertility—who might struggle and how to up women's pregnancy odds," Dr. Streicher says. That includes some low-tech findings—one being that staying at a healthy weight can help. "If you're too thin, you're not producing enough estrogen to ovulate," Dr. Berens says. "If you're too heavy, you're producing too much estrogen, which can throw off your cycle." Another surprising bit of advice: Stay on oral contraceptives until you plan to get pregnant. The longer you are on the pill, the more fertile you are, likely because you're preserving your egg supply, Wise has found. (See How to Boost Your Odds, page 112, for more advice.)

Finally, never say never. "A couple of years ago, I saw a woman who had been told she could never get pregnant due to severe PCOS," Dr. Berens recalls. "She came to see me because she had a strange abdominal mass. Turns out, she was 32 weeks pregnant."

Are you trying to get pregnant? Would you be willing to help researchers examine whether lifestyle factors like diet, exercise and medication affect fertility? Go to sites.bu.edu/presto to find out more about the Boston University Pregnancy Study Online (PRESTO) to see how you can help.