“It’s the biological clock, you know. I only have three years left. After that I’ll have trouble getting pregnant,” says a 32-year-old woman in my office for the first time. Her eyes say, “help!”

Her partner jumps right in. “That’s no way to have a baby. It’s like a trap.” His tone is slightly resentful, but his eyes say, “Please! No!”

They care for each other deeply, but they’re stuck. She wants a baby. He doesn’t.

How Loudly is the Biological Clock Ticking?

She has been listening to well-meant hints from family and friends. “Your biological clock is ticking. It is a time bomb. You have to get pregnant by 35.” She hears versions of this warning over and over. No wonder she is panicked.

Googling some version of “biological clock and pregnancy” didn’t reassure her. A significant number of websites inform her that her fertility will decline rapidly after age 30 (or, on some sites, as early as 27!).

Statistics popularized in the early 2000’s suggest:
• A woman has a 20% chance of pregnancy at age 30; by the time she is age 40, this declines to 5%
• One in three women aged 35 to 39 will not be pregnant after trying for a year.

Does the Biological Clock Really Tick that Loud?

Jean Twenge, a psychology researcher at San Diego University in California, is no stranger to my client’s panic. In The Atlantic, Twenge tells her personal story. In 2002, aged thirty, she was also recently divorced with no children, but a life-long wish to be a mom. She wondered if she’d end up reading Internet message boards where discouraged women over thirty console each other about the stress and disappointments of age-related infertility.

After Twenge married a second time, aware that what’s purported to be fact in the popular media is sometimes different than the actual data, she dug into the original statistical sources for women’s age and fertility. Twenge quickly discovered that the decline in fertility over the course of a woman’s thirties is not as steep as many women believe.

The Biological Clock and Historical Data

Twenge notes that birth data from 1670-1830, an era before electricity and antibiotics, are usually a part of the media story that informs well-meaning friends and relatives who fuel the panic women feel about their biological clocks. She notes, however, that improvements in medical care, nutrition, and fertility treatments are not considered when reporting the data from the 1670-1830 birth records, and thus make those records a poor benchmark for considering contemporary fertility issues.

The Biological Clock and Current Data

Current fertility studies are also better designed than earlier studies. They’re “prospective” instead of “retrospective.” They monitor couples as they are trying to get pregnant instead of asking them to rely on their memories about how long it took them to get pregnant.

It also turns out that there are few well-designed twentieth and twenty-first century studies of the relationship between female fertility and age. The few that are, however, reveal a far more optimistic picture than that most well-meaning friends have. You can read Twenge’s synposis of recent studies and their findings in The Atlantic article here.

Back to my Clients

I suggested to my clients that their well-meaning family and friends, and even many popular websites, might be depending on advice that is more conventional wisdom than actual science. My client couple found Twenge’s article well worth reading.

Reassured that the biological time clock for most women isn’t as loud as they first feared when they came into my office, my couple was able to re-focus on developing the skills and intimacy every couple needs to help them navigate the inevitable issues that face any relationship.