Dr. Shannon Brim discusses the challenges of becoming pregnant at 40 and how to increase your chances.
In the 1970s, the average age of first-time mothers in the United States was 21. By 2020, that average age had jumped to 26. Studies show this trend is mostly due to career goals and financial concerns – children aren’t cheap! Unfortunately, evolution has not caught up with the newer preference of becoming pregnant later in life, and our bodies face some unique pregnancy challenges as we age.
As OB/GYNs, we’ve seen the number of patients asking us questions about pregnancy over 40 rise as well. We thought we would address a few of the most common questions we get and offer some advice for those who are trying to conceive later in their reproductive lifespan.
Is it possible to get pregnant naturally at 40?
YES! While fertility does decline naturally as we age, starting around age 30, it is possible to become pregnant without intervention after age 40. (This is why we often recommend staying on birth control until menopause if pregnancy is undesired…if you are having periods, there is a chance you can get pregnant!)
However, women have a much lower chance of conceiving naturally after 40 than earlier in their reproductive years. Fertility specialists quote approximately a 5% chance per menstrual cycle of getting pregnant naturally after age 40 vs. a 25% chance per cycle for women in their 20’s, which is when fertility typically peaks.
The reason for the decline in successful pregnancies after 40 is multifactorial. The rate of miscarriage is about 40% after the age of 40. This is due to many reasons, but the biggest is a higher chance of genetic abnormalities in each egg. Women’s ovarian reserve also decreases over time, meaning they have fewer eggs by age 40.
How many eggs does a woman have at 40?
When girls are born, their ovaries contain all the eggs they will ever have – about a million in total! This number declines as they age. Women lose about 30 immature eggs a DAY! This means that by the time a woman reaches puberty her ovaries contain 300,000 eggs; by age 30 she’s down to 100,000. Estimates say that by age 40 women only have about 20,000 eggs remaining.
Ovarian reserve can be tested by a physician with a blood test called the Anti-Mullerian Hormone. AMH is a hormone produced by the follicles in a woman’s ovaries where egg cells develop, and it declines through a woman’s reproductive lifespan. The lower a woman’s AMH number, the fewer eggs remain in her ovarian reserve.
However, it’s important to remember that a woman’s AMH test results are just one piece of data that her doctor will look at when discussing her fertility health. They don’t tell anything about the quality of the remaining eggs.
Are my eggs bad after 40?
All women have a percentage of eggs that are genetically abnormal. This means that even if those eggs are fertilized, the pregnancy will not end in a live or genetically normal baby. The percentage of normal eggs a woman has decreases as she ages. At age 25, a woman has approximately 75% normal eggs. By age 35, that number drops to around 45%, and by 40, it’s around 20-30%. This is one reason why most physicians recommend genetic testing for conditions such as Trisomy 21 in a pregnancy over age 35.
How long does it take to get pregnant at 40?
At peak fertility (in their 20’s), the chance of a fertile couple conceiving in any one month is about 20-25%. After a year of unprotected intercourse, approximately 85-90% of those couples will conceive. This is why OB/GYNs generally recommend fertility testing for couples under 35 who have not become pregnant in one year of trying. By age 35, the chance of a successful natural pregnancy drops to 10-15% per cycle, and by 40, the chances hover around 5%. This does not mean conceiving after 40 is impossible, just that it will likely take longer. That’s why the recommendation for considering fertility testing after 40 is only 6 months.
How do I improve fertility after age 40?
There are many ways to improve fertility in general, and they become especially important after age 40. Besides naturally declining fertility, another challenge women over 40 face is that many will have been diagnosed with other conditions which can cause pregnancy complications and/or more difficulties getting pregnant. Examples are obesity, high blood pressure, diabetes, thyroid disorders, fibroids, and endometriosis.
Women with other medical conditions should make sure that their physicians know that they are trying to conceive so that they can optimize their health to prepare for the pregnancy. This may mean changing medications, working on eating healthy, exercising, and weight loss (see Dr. Pound’s 4 Tips for Becoming Pregnant in 2022), or being more aggressive in controlling some conditions like diabetes. A preconception counseling appointment with your regular gynecologist can help pinpoint areas for improvement and give you personalized recommendations.
It is important to take a prenatal vitamin daily when trying to conceive. They help you get the nutrients needed for healthy development of a fetus if you do become pregnant – even before you know it. Some reproductive endocrinologists also recommend supplementation with CoQ10 to help with egg quality.
Is there help if I haven’t gotten pregnant after 40?
YES! Reproductive endocrinologists specialize in assisting women with fertility issues. After age 40, we recommend having a consultation with a specialist if you haven’t become pregnant within 6 months of trying. There are many options for how to proceed depending on a woman’s age and health history, her partner’s age and health history, etc. You can go over these options together and figure out the best plan for you and your partner. We wish you the best of luck!