1. No, your fertility doesn’t fall off a cliff at age 35.

Despite what fear-mongering women’s magazines might suggest, age 35 doesn’t represent some sort of hard stop for your fertile years. In actuality, your fertility is at its peak between your late teens and early 20s and declines gradually throughout your adult life.

However, the downward sloping line between age and fertility does steepen in the mid-30s. While, at age 30, your chance of natural pregnancy is about 20% each month and your chance of pregnancy with in vitro fertilization is about 42% each time you try, by 40, those chances drop to about 5% and 20%, respectively. Additionally, your chances of genetic abnormality—resulting in no pregnancy, miscarriage, or genetic disorders for the baby—increases from 25% to 60–80% in the same decade.

So while 35 isn’t a “cliff,” it is a convenient shorthand for doctors (and, yes, women’s magazines). If you’re thinking about having children after 35, that’s okay—and in fact, it’s becoming the norm in some places (like here in NYC). In fact, it’s been shown that babies born to older moms, who are typically more financially and emotionally stable, gets lots of benefits as a result. But experts recommend freezing your eggs while you’re still young, to ensure that if and when you do want to start a family, it’s possible.

Learn more about age and fertility.

2. Age has, by far, the largest influence over a woman’s fertility.

Sure, there are several things that affect fertility. Genetics, for example, plays a part—women whose mothers, grandmothers, or sisters experienced early menopause are six times more likely to experience it themselves. (“Early” means menopause before age 40—the average age at menopause is 51.) Lifestyle has a hand in it, too. Women who smoke experience menopause, on average, one to four years earlier than their nonsmoking counterparts, and experts estimate up to 13% of infertility could be attributable to smoking. Yikes!

But the connection between age and fertility is by far the strongest. While genetics, lifestyle, medical history, hormonal imbalances, or gynecological issues affect some women, age affects all women—and in a fairly consistent and predictable way. That’s because, as we’ve explained before, women are born with all the eggs they’ll ever have tucked away in their ovaries, and as they age, those eggs are both diminished in number and damaged by inevitable, everyday experiences like fever, sickness, environmental toxins, and the like.

3. Women are not alone— the inverse relationship between age and fertility is seen in men, too.

We hear so often about women’s age and fertility that’s it’s easy to think it’s a problem that just doesn’t affect men at all. That’s just not true; men also experience a decline in fertility with age, though it starts later and it’s less dramatic than women’s. While men’s fertility is never lost entirely the way a woman’s is at menopause, it does decrease over time by several percentage points, which can make a difference especially if the man has a female partner who’s also experiencing age-related fertility decline.

Most of the problems associated with men’s age and fertility stem from a decrease in what doctors call “semen quality.” In short, as a man ages, he may experience a decrease in sperm concentration (that is, the percentage of his semen that contains sperm), motility (or ability to move), and morphology (or the percentage of his sperm that are the normal shape and size). Studies are pretty inconclusive about how drastic this decline actually is and when it begins, but generally agree men experience less than a 1% decrease in motility and morphology per year.

That means that, while men may not be infertile as a result of age, it may take significantly longer for his female partner to get pregnant, even if she’s young and fertile. One study reported that for couples with a male partner who’s 45 or older, it takes on average five times as long to get pregnant than it does for couples with a male partner who’s 25 or younger, regardless of the age of the female partner. There’s also some pretty strong evidence that, similarly to women, older men’s sperm has a slightly higher chance of leading to miscarriage or birth defects like Down syndrome, possibly due to damage to the DNA inside the sperm.

4. Later-in-life celebrity pregnancies aren’t representative of the real chances of conceiving after 40.

Janet Jackson announced her first pregnancy at age 49. Actress Marcia Cross had twins at age 44, as did actress Marcia Gay Harden. News of late-in-life celebrity pregnancies are in the news consistently, and often function as a beam of hope for everyday women who hope to start their families in their 40s. Plus, they’re totally feel-good stories—who doesn’t feel warm and happy seeing Ms. Jackson start a family after four decades in show biz?

But what most celebrities aren’t telling you is that there’s a high likelihood they used assisted reproductive technology, like in vitro fertilization—or, more likely in the case of late-40s pregnancies, an egg donor—to achieve these pregnancies. That’s just the science of age and fertility, and while celebrities are exceptions to a lot of rules, the decline of fertility over time isn’t one of them. And, unlike everyday women, celebrities have thousands of dollars to dedicate to these fertility treatments, which aren’t always covered by health insurance.

It’s understandable that they don’t talk about how they got pregnant; there’s unfortunately still a stigma surrounding infertility, not to mention age (plus, we’re already privy to way too much of celebrities’ personal lives—they deserve at least some privacy). But reproductive endocrinologists (fertility doctors, like those on our team here) unfortunately see way too many women who believe that these high-profile pregnancies are representative of the true relationship between age and fertility.

To give yourself the best chance of conceiving a healthy pregnancy after age 40, you should freeze your eggs in your late 20s or early 30s.

5. There’s no “anti-aging” treatment for your ovaries (yet).

Many women look at the connection between age and fertility like they look at the connection between age and wrinkles, for example—sure, it’s natural that skin might lose a bit of elasticity over time, but it’s nothing that modern medical technology can’t fix. Unfortunately, while Botox, laser therapy, and facelifts provide easy (if expensive) ways to bring your face back to its 20s, the bond between age and fertility is not so simply broken.

That’s because, while skin and most of the other cells in our bodies regenerate over time, like we said above, women are born will all of their eggs—our bodies aren’t producing new ones on the regular. In fact, they don’t produce any new eggs after our reproductive systems finish developing, way back in our mother’s wombs.

There are new studies that demonstrate that stem cells might have some promise as a way to generate new eggs that can develop into offspring. But so far, this has only been accomplished in mice, and we don’t know enough about the way offspring born from the stem cell-created eggs develop to deem it safe for humans to try. This research, while really exciting to experts in human reproduction, is really in its infancy.

For now, the link between age and fertility remains unbroken—there’s no anti-aging treatment for your ovaries.

Still have questions? Learn more about age and fertility.