According to conventional wisdom, on the stroke of midnight on your 27th birthday, Father Time begins to dog your steps and rapaciously guzzle up every last bit of your fertility ("fertility" being Father Time's snack of choice). Pursuing a career and putting having kids on hold is a risky idea, says conventional wisdom, since you might as well be "leaning in" to, um, a tube that goes into your ovaries and sucks out all of your unfertilized eggs one by one (NAILED IT).
Well, ladies, guess what — that's not true. Surprise! In a piece for The Atlantic, psychologist Jean Twenge dispels a lot of misconceptions surrounding aging and fertility. According to Twenge, the widely-cited statistic that states that one in three women ages 35 to 39 will not get pregnant after a year of trying is based on a 2004 article that relies on French birth records from 1670 to 1830. The statistic that states that there's a 30 percent chance of remaining childless forever was also calculated using data from historical populations.
So the raw data most commonly used to support our fertility fears comes from a time at which there was probably a 30 percent chance of contracting a mysterious disease from Moll Flanders. Also a time at which there were no fertility treatments, antibiotics, electricity, etc. To say this study is questionable would be a bit of an understatement.
According to Twenge, there are several more recent studies with much more optimistic findings:
One study, published in Obstetrics & Gynecology in 2004 and headed by David Dunson (now of Duke University), examined the chances of pregnancy among 770 European women. It found that with sex at least twice a week, 82 percent of 35-to-39-year-old women conceive within a year, compared with 86 percent of 27-to-34-year-olds. (The fertility of women in their late 20s and early 30s was almost identical—news in and of itself.)
Another study of 2,820 Danish women trying to get pregnant found that 78 percent of 35-to-40-year-olds got pregnant within a year, compared with 84 percent of 20-to-34-year-olds. Yet another study shows that "among 38- and 39-year-olds who had been pregnant before, 80 percent of white women of normal weight got pregnant naturally within six months."
However, the risk of miscarrying does increase, and not insubstantially, with older mothers. According to the National Vital Statistics Reports, which draw data from the general population, 15 percent of women ages 20-34, 27 percent of women 35-39, and 26 percent of women 40-44 report having had a miscarriage. The likelihood of having a child with a birth defect remains minimal, though: Twenge states that "99 percent of fetuses are chromosomally normal among 35-year-old pregnant women, and 97 percent among 40-year-olds."
What are the implications of this? Fertility rates do decline with age; however, the drop isn't nearly as precipitous as it's often made out to be in the media. Twenge advises to plan on having children, if that's what you want, by age 40. "Beyond that, she says, "you’re rolling the dice, though they may still come up in your favor." So stop stressing. Go forth and conquer. Father Time has better things to do than fuck with your ovaries.
"How Long Can You Wait To Have A Baby?" [The Atlantic]