TLDR: Age and fertility are related for both men and women. With more people waiting longer to start their families, it's worth understanding how your age affects your ability to have a baby and the various options you have to get pregnant.
Are you older than 35 and worried about your chances of getting pregnant? Maybe you’re in your 20s and just considering what that timeline might look like for you. That said, there’s no “best age” to get pregnant. The decision to start a family is deeply personal and one that varies for each person and each family.
So many factors affect your decision to have a baby—and when to do so. There are financial considerations, career goals, travel plans, and especially, your personal feeling of readiness. Thanks to improvements in reproductive technology and access to contraceptives, we have a lot of control when it comes to building a family.
Age, of course, is a factor to consider. The peak reproductive years for women happen before the age of 301 , and as women get older, certain factors may make it take longer to conceive. These days, of course, women are having their first child later in life2 , so for a lot of people, it’s important to understand how your age and fertility are related.
“The so-called ‘biological clock’ exists for everyone, but it affects some people more than others,” says Dr. Joshua Hurwitz3 , a reproductive endocrinologist and partner at Illume Fertility. “The good news is that even those who are experiencing challenges in building their family can be successful with the help of a good fertility specialist. I think the most important thing to understand is that you are not alone and that there are many ways we can help you with modern reproductive medicine.”
How Does Age Affect Eggs?
Women are born with about one million eggs4 . Once you hit puberty, that number is reduced to about 300,000. That number continues to decline, meaning you have a lesser chance of getting pregnant, until menopause, when you no longer ovulate during the menstrual cycle.
The quality of your eggs may also decline, the older you get. When the egg quality is lower, it can cause a higher risk of chromosomal abnormalities, which can cause congenital anomalies and health problems such as Down syndrome. These abnormalities may also cause a higher risk of miscarriage.
How Does Age Affect Women’s Fertility?
For women, fertility changes occur at different ages. Your fertility age begins when you start your menstruation cycle. On average, this starts around 12 years old, but some women begin earlier and some later.
The 20s are thought to be the most fertile years. Your eggs are plentiful and the quality of the eggs is usually the highest during this time. During your 20s and late 20s, your fecundity rate is about 25%5 (fecundity means your ability to get pregnant). If you’re trying to get pregnant and have not had success after a year, talk to your doctor. They will be able to run tests to see what the issue might be.
Once you reach your early 30s, your fecundity rate starts to drop to about 10%. If you’ve been trying for over six months to get pregnant, and you’re over 35, you may want to speak to your ob-gyn about other options, including IVF treatment.
By 40, your fecundity rate may reduce to 5%6 . If you’re over 40, you may want to make an appointment with your doctor or fertility clinic before or as soon as you start trying. They may ask for additional testing, monitor your habits, and thus reduce the risk of complications and increase your success rate.
In your late 40s and 50s, you generally begin menopause. Menopause is when your ovarian reserve no longer ovulates, and your menstruation periods end; you’re said to be in menopause when 12 months without a period go by. The average age for menopause is 51 years old7 .
How Does Age Affect Men’s Fertility?
Unlike the way women are born with a specific number of eggs, men can produce about 100 million sperm every day. However, men’s fertility can also go down as they get older.
By the age of 40, men are 30% less likely8 to help a woman conceive than when they are younger than 30. As men age, their sperm may become less mobile, meaning they don’t swim as well to the egg.
As men get older, their sperm may begin to form an abnormal size and shape. This decrease in sperm quality can reduce their chances of fertilizing an egg. It can also affect the baby’s health; there’s an increased risk for factors like low birth rate and seizures9 associated with “advanced paternal age” (which comprises men over 35). The older the age of the man, the more the risk increases, though this is still a “relatively low” risk according to Stanford Medicine.
How Can I Increase My Chances of Getting Pregnant After 35?
If you’ve decided to wait to have children, you’re not alone. While it may be a bit harder to conceive after 35 than it was in your 20s, it’s possible and happens every day.
There are many small changes you can make to increase your chances of getting pregnant. The good news is, that most of these recommendations contribute to a healthier lifestyle10 overall.
Eat a Healthy Diet
One of the best things you can do to increase your chances of getting pregnant is to eat a healthy diet11 . You should focus on a diet full of whole foods—fruits, veggies, lean protein, whole grains, and healthy fats.
Healthy fats, like omega-3s from fatty fish like salmon and nuts, have been shown to have positive effects on pregnancy rates and female fertility12 . Conversely, a diet high in trans fat has been shown to reduce fertility.
Manage Your Stress
Stress can be a normal part of life. While you may not be able to take away all stressful situations, prolonged stress can negatively impact fertility. Learning how to manage stress can help reduce the effects of stress on fertility. One way to manage stress is by practicing meditation.
If you are experiencing fertility issues, mindful meditation can help alleviate some of your worry. In a study on mindfulness and infertility, women who engaged in a daily mindfulness practice reported feeling less depressed 13 and defeated and felt less self-judgment and shame.
Exercise
Moderate exercise may be helpful with fertility. Exercise is also a great way to lower stress. Yoga, pilates, and walking are all moderate exercises that can be helpful with fertility.
Don’t overdo it though! Exercising too much can cause fertility issues14 and has been shown to lower the gonadotropin-releasing hormone, which may cause ovulation issues.
If you have questions about your exercise routine, talk to your doctor. They will be able to guide you to what is best for you and your fertility journey.
Quit Smoking
We’ve known for a while now that smoking is bad for you, and here's another reason to kick the habit—smoking can lower fertility rates15 .
The good news is the effects of smoking are thought to only be harmful to your fertility while you’re smoking, so if you quit, the negative effects appear to be reduced. In a study on smoking and fertility treatments, women who smoked had a 50% reduction in implantation compared to women who had never smoked. Women who previously smoked but stopped smoking before treatments had the same implantation rates as non-smokers.
Lower Your Alcohol Consumption
The occasional drink doesn’t seem to have a huge effect on fertility, but drinking moderate and large amounts of alcohol may cause negative effects on pregnancy.
Women who have hangovers are more likely to experience infertility issues. This means the amount of alcohol depends on the person’s tolerance level, not necessarily the amount they drink.
While it’s unclear why alcohol affects fertility, it may be because of how it increases estrogen levels16 , which can affect ovulation.
What Are Fertility Options If You’re Older?
If you’re over the age of 35 and have been trying to get pregnant for more than six months, you should schedule an appointment with your ob-gyn. They should be able to help determine any issues through bloodwork or ultrasounds, and your partner may be asked to provide a sperm sample.
If you’re over 40, you may want to talk to your doctor right away. They may be able to give you tips for boosting your fertility before you even start trying.
If you’re unable to conceive through sexual intercourse, there are reproductive technologies that you can discuss with your doctor to see what is right for you and your unique situation.
Intrauterine Insemination (IUI)
Intrauterine insemination, which used to be known as artificial insemination, is used to increase the chances of fertilization. Before IUI is done, you may be instructed to take medication to stimulate egg production. If your partner is male, he will be asked to provide a sperm sample, and it will be “washed.” This means debris and seminal fluid are removed to make the sperm super concentrated. If you are using a sperm donor, the sample will be thawed.
Once ovulation has occurred, the doctor inserts a small tube into the uterus to introduce the sperm. This procedure is usually painless and doesn’t require anesthesia.
IUI may be a good option for women who still ovulate, have a partner with a low sperm count, or need to use donor sperm.
In Vitro Fertilization (IVF)
In vitro fertilization may also be suggested for women who are older. IVF is shown to be the best treatment option17 for women over 40.
In the IVF process, you will be advised to take medication to stimulate your ovaries. Your ob-gyn will then remove mature eggs from your ovaries while you are sedated. Healthy eggs are then mixed with your partner or donor’s sperm and incubated. The embryos are then transferred into your uterus.
Unlike IUI, IVF is more invasive. There are risks with IVF18 , which can include multiple pregnancies, miscarriage, and premature delivery. Talking to your doctor can help you understand your risks and help you make the best decision for you.
Egg Donor In Vitro Fertilization
If you’re not able to ovulate for any reason, including your age, IVF is still a viable option. You can use donor eggs in the same process as described above, except for the retrieval of eggs.
Freezing Your Eggs
More and more women are deciding to freeze their eggs. With this option, women can focus on other aspects of their lives before becoming a mother.
If you decide to freeze your eggs, you will be given medication to stimulate your ovaries to produce mature eggs. They will then be removed while you’re under general anesthesia.
Are There Benefits of Getting Pregnant When You’re Older?
While age and fertility seem to be very related, having children at an older age has its benefits. One study showed that longevity was longer19 for women who had children later in life. You may also be in a better financial position for raising children.
Conclusion
Age and fertility play a large role in your ability to conceive. Once you hit 35, your fertility begins to decline, but lots of women go on to have healthy pregnancies in their late 30s and 40s.
The biggest reason for the decline in fertility is the quality and quantity of eggs a woman has. By eating a healthy diet, managing stress, exercising, and abstaining from smoking and alcohol, you may be able to prolong the health of your eggs.
“Remember to be proactive,” says Dr. Hurwitz. “Seek out family-building information and help from experts when needed. Everyone deserves access to proper guidance to help navigate the fertility challenges they may be facing.”
