There are so many things to consider in planning when to have a baby. If you plan to get pregnant at 35, your career is more likely to be on solid footing. But if you can get pregnant at 30, you might be able to complete your family before your fertility starts slipping. If you account for all factors, is there an ideal time to get pregnant?
“There’s no good time,” says Genevieve Eastabrook, a maternal-fetal medicine specialist at London Health Sciences Centre. It’s true that there’s always something that gets in the way, whether it’s finishing school or making partner at your firm. But when it comes to the physiological side of the decision (factoring in how long it will likely take to conceive and at what age the risks of complications begin rising), there is an ideal window. “According to all of the epidemiological data we have, there is a sort of sweet spot between your early 20s and age 34,” notes Eastabrook, who is also an assistant professor at the Schulich School of Medicine & Dentistry at Western University.
Once you reach age 35, the chances of conceiving start dropping. “At first, the odds don’t drop very fast, but they start declining slowly,” explains Basim Abu-Rafea, medical director of The Fertility Clinic at London Health Sciences Centre. According to the American Society for Reproductive Medicine, in the first month of trying, a 30-year-old woman has about a 20 percent chance of getting pregnant. By age 40, those odds are about five percent. Of course, chances are higher when you try for more than one month, but even once you do get pregnant, the risk of miscarriage increases with age—from about 15 percent when you’re 20 to anywhere from 30 to 40 percent when you’re 40. According to Neal Mahutte, medical director of The Montreal Fertility Center, this is typically due to genetic abnormalities in the egg, which become more common with age.
Complications also become more common after age 40. “The ones we see more commonly in older moms are gestational diabetes, gestational hypertension, pre-eclampsia and preterm birth,” says Eastabrook. “We see a slightly higher proportion of what we call ‘small for gestational age’ babies and a higher risk of Caesarian section,” she adds. The chances of having twins (which brings its own risks) and babies with chromosomal differences, such as Down syndrome, also increase. But in many cases, the risks are not all that much higher. Between 2006 and 2009, 12.7 percent of first-time moms between 20 and 34 had babies who were small for their gestational age, compared to 13.3 percent of those 35 to 39 and 15.4 percent of first-time mothers 40 and older. These risks may also be lower for women who don’t have health issues before becoming pregnant and who eat well and exercise regularly.
That’s good news for Canadian women, who have been waiting longer to have their first babies in general. Women ages 30 and older account for 42 percent of first-time mothers in Canada. And women over 35 are the fastest-growing segment of new moms, says Eastabrook. Research suggests that economic factors that are making it harder to achieve financial security and longer searches for the right partner are some of the reasons for the delay in pregnancy.
Having a baby after 30 may actually be beneficial in some ways. Studies suggest that women who give birth later in life have a higher lifetime earning potential than mothers who have children earlier. As well, those who get pregnant after age 35 may be more likely to live past age 95 and stay mentally sharp into old age, possibly because of the later surge in pregnancy-related hormones. Their babies may benefit, too: Some research suggests that children born to older mothers are more likely to attend college and do better on standardized tests than those whose mothers give birth at a younger age.
Of course, many of the factors surrounding when women get pregnant are decided for them, whether they’re waiting for the right partner or the right line to show up on a pregnancy test. Fortunately, help is available if you’re trying to get pregnant and you’ve already passed your ideal window. If you’re still deciding on the right time, it’s worth making an appointment with your doctor to discuss your options so that you can make an informed decision on what’s right for you.