Unlike other species, humans have a choice when it comes to timing pregnancy. And while the window of opportunity spans decades, there is still the biological reality that fertility decreases with age and ceases for most women by the mid-40s.

Historically, women began having babies in their late teens and 20s. However, with the advent of the birth control pill in the 1960s—a contraceptive method viewed as easy, reversible, and reliable—women were afforded the ability to decide when it would be best to have children. The ability to control fertility not only opened up new opportunities, it also led to delayed childbearing. And this has contributed to an increasing number of women facing age-related infertility.

While the optimal age for reproduction from a biological standpoint remains between 15 and 28, the average age of a first-time mother continues to rise. In fact, it is now over 26 years old across the United States. In certain regions, such as in large urban areas and on the coasts, the average age exceeds 30 (source: National Center for Health Statistics).

When it comes to fertility, all women are different. Although the uterus has demonstrated its ability to function as a baby-carrying organ until around age 55 (and beyond), the eggs of women are significantly more age-sensitive. Women are born with all the eggs they will ever have any signs of aging become evident as early as the late 20s and are more profound in the latter half of the 30s. The pace of decline in egg quality and quantity is multifaceted, and genetics plays a role. Some women will become pregnant quickly into their 40s while others show a significant drop off infertility in their mid-30s. Because there is such a wide variance, delaying childbearing can be a risky decision.

“It can be difficult to determine when is the right time to make the shift from trying not to get pregnant to planning for pregnancy,” says Dr. Nicole Noyes, fertility preservation and in vitro fertilization specialist at Northwell Health. “Some women are just more fertile than others, so it’s a good idea to talk to your doctor at around 28 years of age if you want to have a child.”

Taking the next step

For some women approaching the end of peak fertility, the right decision may be to begin trying to conceive. A history and physical exam focused on reproductive function, along with blood tests measuring hormone levels and an ultrasound of the ovaries can help to predict the likelihood of getting pregnant.

Women who want to continue to delay childbearing should discuss their options with a fertility specialist. This includes exploring the option of storing frozen eggs or embryos created at a time when a woman is at a more ideal “egg-age.” While freezing technology used to store eggs and embryos has substantially improved over the last several decades, a woman’s chances of giving birth to a child from eggs that she has frozen becomes lower with each advancing year after age 28. Because younger eggs are more likely to produce successful pregnancies, women may want to consider egg freezing sooner than later.

If you’re weighing the decision to have children, a good place to start is asking yourself some important future-focused questions:

• Where’s my life going?
• What are my priorities?
• What’s my plan for the next 10 years?

Your answers may help determine the next best steps for you. The decision to have a baby is unique for every woman. Based on your current situation and goals for the future, you can make a decision that feels right for you.

Learn more about family planning and fertility. We’re here to answer your questions. Call the Katz Institute for Women’s Health Resource Center at 855-850-5494 to speak to a women’s health specialist.