If I had a nickel for every time someone asked me when I was going to settle down and have kids after my thirtieth birthday, well…let’s just say I’d have a lot of nickels.
I was never overly concerned about having kids. I enjoyed the single lady life, and being a furmom was all the responsibility I cared to take on in my twenties.
It wasn’t until my younger brother and his wife not only had a baby, but lapped me with a second child, that I started to panic about having children.
I was approaching 30 years old. Despite being married, actually being a mom felt farther away than it had when I was 20.
As I blew out the candles on my thirtieth birthday cake, the one question that lurked in the back of my mind was, “How long can I really wait to have to have a baby?”
Historically speaking, statistics are scary.
You’ve probably seen the numbers on a poster or pamphlet in your OB-GYN’s office. According to oft-cited statistics, only 67 percent of women over the age of 35 will conceive within a year. After a woman is 40 years old, that number drops to around 40 percent. By age 43, natural conception percentages plummet to under 5 percent.
In a time when researchers study everything from how to unboil an egg to intense make-out sessions, it’s reasonable to assume there’s plenty of modern fertility research being done.
Surprisingly, that is not the case. Those scary fertility statistics that make the rounds in women’s magazines every few months are actually based on data from 300-year-old French church records.
According to a report by the BBC, researcher Jean Twenge found that "the data on which that statistic is based is from 1700s France. They put together all these church birth records and then came up with these statistics about how likely it was [someone would] get pregnant after certain ages."
In the 1700s, doctors (all men, naturally) really believed that the womb could wander all over a woman’s body, so pregnant women didn’t exactly have access to the best health care. Nutrition was poorly understood, and the average life span during this time was only about 40 years old.
Women who knew they were reaching peak life expectancy probably tried to avoid pregnancy. Although they didn’t have access to modern birth control, there were other ways to prevent pregnancy.
Yet modern scientists and doctors continue to cite these statistics, striking fear in the hearts of 30-something women hoping to get pregnant one day.
So what do modern statistics say?
There is surprisingly little modern natural conception research being done today. One of the problems with current research is that many studies are based on women undergoing fertility treatments such as in vitro fertilization (IVF). In large part this is because studies about unaided conception are often difficult to accurately report.
It’s not that studies of women undergoing fertility treatments are inaccurate. Instead, the problem is that they only represent a small fraction of women trying to get pregnant at different ages.
Only about 1.5 percent of babies born each year were conceived with fertility treatments. Most current fertility research simply doesn’t apply to the other 98.5 percent who were conceived naturally.
When it comes to a woman’s ability to get pregnant after a certain age, most current research is almost as bleak as the data from 300 years ago. But it paints an incomplete picture of fertility.
In her revealing essay in The Atlantic, Twenge interviewed Dr. Allen Wilcox, who shed light on why infertility rates among women over the age of 35 seem so high.
According to Wilcox, “The observed lower fertility rates among older women presumably overestimate the effect of biological aging. …If we’re overestimating the biological decline of fertility with age, this will only be good news to women who have been most fastidious in their birth-control use, and may be more fertile at older ages, on average, than our data would lead them to expect.”
Though they are few, recent natural conception studies suggest promising news for hopeful moms-to-be.
A widely cited 2004 study by Dr. David Dunson looked at over 700 women who were actively trying to get pregnant across a wide age spectrum. Dunson concluded that 82 percent of women between the ages of 35 and 39 would naturally conceive within one year, compared with 86 percent of women in their twenties.
Corroborating Dunson’s research is a larger 2013 study done by Dr. Kenneth Rothman that found that 77 percent of women between the ages of 35 and 40 conceive naturally within a year, compared to 83 percent for women in their twenties. Both studies found only a marginal difference of 4 to 5 percent in conception rates in women over age 35.
These research studies, while small, are encouraging as more women than ever delay starting a family.
What does influence fertility?
Women over the age of 35 often shoulder the burden of fertility issues in the mistaken belief that their age alone is the reason that they struggle to get pregnant.
In reality, there are many factors that influence a woman’s fertility: genetics, fallopian tube dysfunction, and endometriosis, to name a few. Fallopian tube disorders and endometriosis alone account for as many as 55 percent of infertility cases, and these can occur in women of any age.
Additionally, about 35 percent of infertility cases can actually be traced back to a problem with the man.
Although it is true that a woman’s fertility does sharply decrease after age 40, the odds of getting pregnant naturally after 40 are still pretty good—around 50 percent. Pregnancy after 40 does carry a higher risk of chromosomal abnormalities, however.
For a woman in her twenties, the risk of abnormality is about 1 in 500. By the time women reach age 40, that number jumps to about 1 in 60.
That number does seem frightening, but David James of the National Institute for Health and Care Excellence says, "Turning that on its head, it does mean that 59 out of 60 women aged 40 will have no chromosomal problems in their baby at all."
So what’s a woman to do?
The jury is still out on how long women can really wait to have a baby. However, current research does show that most women can wait to have children until well after age 30.
After all, the world’s most prolific surrogate mother just became pregnant with her sixteenth child at age 46.
For healthy couples with no known heredity issues that might affect a fetus’ development, pregnancy is most likely safe. But ultimately, it’s a decision women should discuss with their doctor and partner.
Dr. Neil Gleicher, founder of the Center for Human Reproduction, is optimistic about the future of pregnancy at any age. In an interview with the Business Insider, he remarked, "We will reach a threshold where age no longer matters and women will be able to conceive probably pretty much independent of their age."