What are your chances of getting pregnant at different ages?

What are the chances of getting pregnant?

Your chances of getting pregnant depend in large part on your age. If you're in your 20s or early 30s, odds are good that you'll get pregnant within six months of starting your TTC (trying to conceive) journey.

"For healthy couples in their 20s and early 30s, around 1 in 4 women will get pregnant in any single menstrual cycle," says the American College of Obstetricians and GynecologistsOpens a new window (ACOG). The American Society for Reproductive Medicine (ASRM)Opens a new window estimates that about 80% of women will become pregnant in the first six months of trying.

Chances of getting pregnant decrease as a woman ages, especially after age 35. Once you hit that birthday, your odds decline along with the number and quality of your eggs. By age 40, women have a 5% to 10% chance of getting pregnant per menstrual cycle.

There are many possible causes for the age-related drop in fertility, but the main reason is that you have fewer eggs, and a higher percentage of abnormal eggs, as you age.

Amazingly, you have the greatest number of eggs available when you're still a baby in your mother's womb: At 20 weeks, female fetuses have up to 6 or 7 million egg-containing follicles in their ovaries. At birth the number is about one million, and by puberty the egg count drops to about 300,000.

At age 37 you have about 25,000 eggs, and by age 51 (the average age of menopause), you'll only have about 1,000 eggs left. Throughout your menstrual cycles, ovulation will use up some of your egg-containing follicles, but most will be lost through a natural degeneration process called atresia.

Your eggs decrease in quality as you age, too. That means the remaining eggs are more likely to have abnormal chromosomes. This can prevent pregnancy from happening, cause miscarriage, or lead to genetic problems such as Down syndrome.

Also, as you get older you're more likely to have developed conditions – such as endometriosis and uterine fibroids – that can affect your fertility.

It's not all doom and gloom for older moms-to-be, though. Though eggs age, the uterus is often perfectly healthy and capable of pregnancy.

"A woman can still carry a pregnancy at an older age, especially if she previously froze her eggs or embryos," says Sasha Hakman, M.D., a double board-certified ob-gyn and reproductive endocrinologist who specializes in treating infertility at HRC FertilityOpens a new window in Los Angeles.

"Women who are planning to conceive at an older age are at higher risk of pregnancy complications, but with proper medical screening can go on to have a healthy pregnancy," says Dr. Hakman, who is a member of the BabyCenter Medical Advisory Board.

Fertility by age

Here's a rundown of how fertility changes over the years. Estimates vary (sometimes by a lot) according to sources. The data on chances of pregnancy within 6 and 12 menstrual cycles is from a studyOpens a new window published in the American Journal of Obstetrics and Gynecology of almost 3,000 couples with no history of infertility.

In your 20s

Chances are about 25% that you'll get pregnant in any single menstrual cycle if you're trying to get pregnant in your early 20s, according to ACOG. 

Women between the ages of 21 and 24 have a 57% chance of becoming pregnant within 6 menstrual cycles, and a 71% chance of pregnancy within 12 cycles.

Women between the ages of 25 and 27 have a 59% chance of becoming pregnant within 6 cycles and a 79% chance of pregnancy within 12 cycles.

Between 28 and 30, the chances are 62% within 6 cycles and 78% within 12 cycles.

In your early 30s

At age 30, you have about a 20% chance of getting pregnant each month that you try, according to ASRM. But beginning at age 32, says ACOG, fertility decreases gradually but significantly.

Between the ages of 31 and 33, you have a 61% chance of pregnancy within 6 cycles and a 77% chance within 12 cycles.

In your mid-to-late 30s

Fertility declines more quickly once you're in your mid-30s and, according to ACOG, it decreases rapidly after age 37.

Women who are 34 to 36 years old have a 56% chance of pregnancy within 6 cycles and a 75% chance within 12 cycles. Those who are 37 to 39 have a 46% chance within 6 cycles and a 67% chance within 12 cycles.

In your early 40s

By age 40, around 1 in 10 women will get pregnant per menstrual cycle, says ACOG. According to ASRM, your chance of pregnancy at age 40 is less than 5% per cycle.

Women ages 40 to 45 are 60% less likely to conceive in any given cycle than women in their early 20s. But it is possible: Women in their early 40s have a 28% chance of pregnancy within 6 cycles and a 56% chance within 12 cycles.

In your mid-to-late 40s

"By 45, fertility has declined so much that getting pregnant naturally is unlikely," says ACOG.

Keep in mind that even if you haven't reached menopause, you may still not be able to become pregnant.

"Women do not remain fertile until menopause," says ASRMOpens a new window. "The average age for menopause is 51, but most women become unable to have a successful pregnancy sometime in their mid-40s."

When can a woman not get pregnant?

Theoretically, any woman who's menstruating can get pregnant, though it's very unlikely after age 45.

Also, some women of all ages have impaired fecundity, meaning it's difficult or impossible for them to get pregnant or carry a pregnancy to term.

According to the Centers for Disease Control and PreventionOpens a new window (CDC), 13.4% of women who have never given birth will face challenges while trying to have a baby.

For women trying to have their first child, the rates of impaired fecundity are:

15 to 29 years: 9.2%
30 to 39 years: 22%
40 to 49 years 33%

Women who have given birth before are less likely to have trouble. Their impaired fecundity rates are:

15 to 29 years: 12%
30 to 39 years: 12%
40 to 49 years: 14.5%

When does fertility decline?

Fertility declines in your 30s, starting at age 32. But that doesn't mean you'll necessarily have any trouble getting pregnant. You still have a 67% to 75% chance of getting pregnant in your 30s within a year of TTC.

According to the Centers for Disease Control and Prevention (CDC), about 22% of couples in which a woman in her 30s is trying to get pregnant will have problems conceiving their first child. But that means 78% won't have trouble getting pregnant.

What age are women most fertile?

Unfortunately, a woman may be most fertile when she's not yet ready to have kids. "A woman's peak reproductive years are between the late teens and late 20s," according to ACOG.

(Fertility for men also decreases with age, but not as predictably as for women.)

Of course, you don't need to be at peak fertility to get pregnant and start a family. In the United States, most births are to women between the ages of 30 and 34, followed by women ages 25 to 29. According to CDC data:

Women ages 15 to 17 have 5.6 births per 1,000 females
Women ages 18 to 19 have 25.8 births per 1,000 females
Women ages 20 to 24 have 57.5 births per 1,000 females
Women ages 25 to 29 have 93.5 births per 1,000 females
Women ages 30 to 34 have 97.5 births per 1,000 females
Women ages 35 to 39 have 55.3 births per 1,000 females
Women ages 40 to 44 have 12.6 births per 1,000 females
Women ages 45 to 49 have 1.1 births per 1,000 females

Can you increase your fertility at any age?

Yes. There are many things you can do to maximize your chances of getting pregnant, such as quitting smoking, limiting alcohol and caffeine, maintaining a healthy weight, and minimizing stress. (Though keep in mind that your fertility will decline with age, even if you're taking excellent care of yourself.)

You can also increase your chances of pregnancy at any age by being aware of when you ovulate and timing sex accordingly. And you may benefit from assisted reproduction techniques, such as in vitro fertilization (IVF), intrauterine insemination IUI, and fertility medications. These procedures won't reverse the natural fertility decline that happens with age, but they may be able to help you get pregnant.

In addition, if you're younger and know you may need or want to delay pregnancy, you might consider egg freezing or embryo banking. With egg freezing, several eggs are removed now (when you're more fertile), frozen, and later used for in vitro fertilization (IVF). With embryo banking, the eggs are fertilized with your partner's sperm using IVF and frozen for later use.

Learn more:

• How to prepare for pregnancy
• Getting pregnant in your 30s
• Getting pregnant in your 20s
• Pregnancy after 40