The Fertility 'Cliff'- When is it Too late to Conceive?

In our modern era, women are breaking down barriers and spearheading innovation. Women are now more likely than men to have earned a bachelor’s degree by the age of 29, own close to 10 million businesses, and make up more of the labor force each year (source). It’s no surprise that having a baby before the age of 27 sometimes isn’t an option, whether it’s because of career goals, educational advancement, or not finding the right partner just yet. Unfortunately, our bodies aren’t on the same page, as sources claim that fertility begins to decline around the late twenties (source).

By the time a woman reaches the age of 35, her chances of getting pregnant in a single cycle drop even more significantly. After the age of 40, women have less than a 5% change of getting pregnant in a cycle (source). Still, we all personally know women and see celebrities that get pregnant later in life. Though getting pregnant later in life isn’t the norm for everyone, you may wonder how far the fertility cliff actually drops.

In a 2002 study, David Dunson of the National Institute of Environmental sciences studied nearly 800 couples that were using the rhythm method of contraception. He found that women aged 27 to 34 experienced a 10% drop in ability to conceive in a single cycle compared to women aged 19 to 26 with partners of a similar age. It’s important to note that Dunson measured a woman’s probability to conceive in each cycle, not a woman’s probability to get pregnant overall (source). The length of a woman’s fertile window stays constant throughout her life as well, holding at a steady 5-6 days, which may be comforting to some hopeful parents-to-be. The study also found that both men and women’s age affects the time it takes to conceive, though men only see a significant decline in their fertility after the age of 35.

The statistics above can sound scary, but it’s not so bad in perspective. Do you remember hearing that 1/3 of women over the age of 35 can’t conceive after a year of trying? Researchers have proven that this is a false claim based on 300-year-old science (source). David Dunson’s research shows that while the single-cycle rate of conception drops steeply for women after the age of 35, 82% of women between the ages of 35-39 still get pregnant after trying for one year (compared to 86% of women between the ages of 27 to 34). This 4% drop is miniscule compared to what we have been led to believe.


Despite what this new research shows, every woman knows that she will eventually be unable to conceive. The scary part is that there is no exact age that applies for everyone—fertility is deeply personal and individualized. Some women may easily get pregnant at the age of 38, while others will experience trouble conceiving at the age of 30. 

So, when is it time to worry?

According to the American College of Obstetricians and Gynecologists, “given the anticipated age-related decline in fertility, the increased incidence of disorders that impair fertility, and the higher risk of pregnancy loss, women older than 35 years should receive an expedited evaluation and undergo treatment after 6 months of failed attempts to conceive or earlier, if clinically indicated” (source). So, even if you have tried to get pregnant for a few months, it still may not be time to panic.

The problem with labelling the drop in fertility after the age of 35 as a fertility “cliff” is that the name is misleading. Dr. Suleen Kansal Kalra, MD, MSCE at the University of Pennsylvania, instructs women to picture the decline in fertility as a “line that’s gently sloping downward. Then picture the slope steepening after 35” (source). 

The main lesson to take away from all of this is that women don’t tumble off a cliff after the age of 35. Different factors affect each individual, and plenty of people successfully conceive a healthy child in their thirties and even forties. Though it may take a little more time to get pregnant as you get older, it’s still possible. If you run into complications with getting pregnant after six months, there are a vast array of treatments and options to consider.

The fertility cliff is more like a gently rolling hill-- you won’t experience a steep fall off of it.