Age and fertility are closely connected because both the number and quality of eggs change over time. Fertility does not suddenly decline at 35, but the gradual decline that often begins in the late 20s or early 30s becomes more noticeable after the mid-30s. That is why fertility testing may be recommended sooner for people trying to conceive after 35 and why those over 40 may benefit from talking with a fertility specialist even earlier.
Understanding these changes can help you make informed decisions about trying to conceive, fertility testing, IVF, or egg freezing based on your own timeline and goals.
What Is the Connection Between Age and Fertility?
People with ovaries are born with all the eggs they will ever have—about two million at birth and about 600,000 by puberty. Over time, both egg quantity and egg quality decline as part of the normal reproductive aging process.
The American Society for Reproductive Medicine (ASRM) notes that female fertility is highest in the late teens and twenties, then generally begins to decline in the late 20s or early 30s and declines more rapidly after age 35. However, there is no single birthday when fertility suddenly changes. The process is gradual, and every person’s reproductive health is different.
Two parts of reproductive aging are especially important: ovarian reserve and egg quality.
What Is an Ovarian Reserve?
Ovarian reserve refers to the estimated number of eggs remaining in the ovaries. It naturally decreases with age, although the rate of decline varies from person to person.
Tests such as anti-Müllerian hormone, or AMH, can measure AMH level, and along with antral follicle count help a fertility specialist estimate ovarian reserve. These results may also help predict how the ovaries could respond to fertility medications.
Ovarian reserve testing does not provide a simple “fertile or infertile” answer, however. A lower ovarian reserve does not mean pregnancy is impossible, and a higher ovarian reserve does not guarantee pregnancy.
How Does Egg Quality Change With Age?
Egg quality generally refers to an egg’s ability to fertilize, develop into a healthy embryo, and support an ongoing pregnancy. Unlike egg quantity, there is no routine blood test that directly measures egg quality.
Age gives fertility specialists important information about expected egg quality because, as eggs age, the risk of chromosomal abnormalities increases. This can make conception more difficult and raise the risk of miscarriage, including age-related conditions such as Down syndrome. By age 35, about 20% of human eggs are aneuploid.
How Does Fertility Change After 30?
For many people, fertility after 30 remains strong, even though fertility can slowly decline after age 30 rather than changing overnight when you leave your 20s.
During the early 30s, ovarian reserve and egg quality continue their gradual decline, but many women still conceive during this decade. This can make your 30s a useful time to think more intentionally about your reproductive timeline, especially if you know you want children but are not sure when you will be ready to conceive.
You do not need to be actively trying to become pregnant to have a conversation about fertility. A consultation can help you understand your medical history, discuss family-building goals, and determine whether testing or fertility preservation would provide useful information based on your stage of life.
If you are unsure whether it may be time to talk with a fertility specialist, FEA’s fertility quiz can be a helpful starting point.
What Should You Know About Fertility After Age 35?
Thirty-five is not a fertility deadline. It is a clinical milestone because fertility decline tends to accelerate during the mid-30s, so women aged 35 and older are advised to seek infertility evaluation sooner as age-related changes become more clinically important.
ASRM recommends a fertility evaluation after six months of regular, unprotected intercourse without pregnancy when the female partner is 35 or older. For patients under 35 without other known risk factors, evaluation is typically recommended after 12 months.
Trying to conceive after 35 does not automatically mean you will need fertility treatments. It simply means there may be value in evaluating potential barriers sooner rather than continuing to try for another six months without additional information. Miscarriage risk is already over 20% for women aged 35, although many still conceive without treatment.
You may also benefit from earlier evaluation at any age if you have irregular or absent periods, known or suspected endometriosis, previous ovarian surgery, a history of chemotherapy or radiation, concerns about sperm health, or another condition that may affect fertility.
Can You Still Get Pregnant After 40?
Yes. Pregnancy after 40 is possible, but natural fertility is lower than it was earlier in the reproductive years, and age becomes an increasingly important consideration when choosing how long to try before seeking help; by ages 40 to 41, the chance of getting pregnant after 12 months is about 54%.
ASRM guidance indicates that more immediate fertility evaluation and treatment may be appropriate for women over 40 rather than waiting six or 12 months. Women ages 40 to 44 also face an increased risk of miscarriage of about one in three, rising to nearly 55% by age 42.
A consultation does not commit you to IVF. It gives you the opportunity to evaluate ovarian reserve, ovulation, reproductive anatomy, sperm health when applicable, and other factors that may affect conception, including higher risks for chromosomal disorders, birth defects, and pregnancy complications such as gestational diabetes and preeclampsia in older mothers.
For someone considering fertility after 40, getting this information earlier can help make the available options clearer.
When Should You Consider Fertility Testing?
The general guidelines are:
- Under 35: Consider evaluation after 12 months of regular, unprotected intercourse without pregnancy.
- Age 35 to 40: Consider evaluation after six months.
- Over 40: Talk with a fertility specialist about whether evaluation should begin right away.
- At any age: Seek help sooner when you have known reproductive concerns, irregular cycles, previous reproductive surgery, endometriosis, recurrent pregnancy loss, male-factor concerns, or other medical factors that may affect fertility.
You can also request fertility testing before you begin trying if you want more information to guide future family planning.
What Fertility Tests May Be Recommended?
A fertility evaluation looks at more than age alone. Age significantly influences reproductive capacity for both sexes, not only women’s fertility. Your reproductive endocrinologist may review your menstrual cycles, pregnancy history, medical history, medications, previous surgeries, and how long you have been trying to conceive.
Testing may include:
- AMH testing and other hormone bloodwork
- Antral follicle count through ultrasound
- Evaluation of ovulation
- Imaging of the uterus and ovaries
- Testing to determine whether the fallopian tubes are open
- Semen analysis when applicable
Although men produce sperm throughout life, sperm quality declines with men’s age, and sperm count and motility also tend to fall, especially after 40 to 45. The age of the male partner can combine with the other partner’s age to affect conception chances and reproductive outcomes.
What Does AMH Testing Measure?
AMH testing helps estimate ovarian reserve, or egg quantity. It does not directly measure egg quality or predict whether you will become pregnant naturally.
Your fertility specialist interprets AMH alongside your age, ultrasound findings, reproductive history, and other test results rather than using one number to determine your fertility potential.
If you want a closer look at how an evaluation works, FEA also explains what to expect during a first fertility visit.
When Should You Consider IVF?
IVF may become part of the conversation when testing identifies factors that make other approaches less effective, when previous fertility treatment has not resulted in pregnancy, or when age and ovarian reserve make time an important part of treatment planning. Assisted reproductive technologies can help mitigate age-related fertility declines, and common options for women over 35 include intrauterine insemination and IVF.
During in vitro fertilization (IVF), eggs are retrieved from the ovaries and fertilized with sperm in a laboratory. An embryo may then be transferred to the uterus. IVF success declines with age, especially after 35. For women ages 35 to 37, 40.6% of egg retrievals led to live births, while after three IVF cycles, 25% of women ages 40 to 41 had a baby.
IVF after 35 or IVF after 40 is not automatically recommended based on age alone. Your reproductive endocrinologist will consider your ovarian reserve, sperm health, reproductive anatomy, diagnosis, previous pregnancies or treatments, and personal goals.
IVF also cannot reverse the natural effects of age on egg quality. This is why individual testing is more useful than assuming IVF will or will not be necessary based only on your age.
Should You Think About Egg Freezing?
Egg freezing may be worth discussing if you know you want children in the future but are not ready to try to conceive now, and it can help some people achieve future family-building goals.
The process involves stimulating the ovaries, retrieving mature eggs, and freezing them for possible future use. Importantly, egg freezing preserves eggs at the age they are retrieved. It does not stop your body from continuing to age, and it cannot guarantee a future pregnancy.
Age at the time of freezing plays an important role in future outcomes because egg quality changes over time. If you are considering delaying pregnancy, learning about fertility preservation and egg freezing earlier can help you decide whether it fits your plans, since freezing eggs at a younger age generally preserves better egg quality than waiting longer.
When Is the Right Time to Schedule a Fertility Consultation With Fertility Specialists?
You do not have to reach a certain age or receive an infertility diagnosis before asking questions about your fertility.
A consultation may make sense if you have been trying according to the timelines above, are considering pregnancy after 35 or 40, want to understand your ovarian reserve, are thinking about egg freezing, or simply want more information before making decisions about your future family. A fertility clinic can also explain how a male partner’s age affects conception, including a 28% failure rate to conceive with a 40-year-old partner and a 50% higher miscarriage rate after about 45 as sperm quality declines and DNA fragmentation in sperm becomes more common.
Early fall can be a particularly practical time to begin planning. If starting or growing your family, pursuing fertility testing, or exploring egg freezing is one of your goals for next year, scheduling an evaluation in September or during the fall gives you time to gather information without feeling like you need to make an immediate treatment decision.
For patients looking for a fertility specialist in Louisville, KY, Fertility & Endocrine Associates provides fertility evaluation, fertility preservation, IUI, IVF, donor eggs when age makes pregnancy with your own eggs less likely, and other reproductive care that supports women’s health for patients throughout Louisville and surrounding Kentucky communities.
Your age provides important context, but it is only one part of your fertility picture. Testing can help you understand what is happening now and have a more informed conversation about what comes next.
If you are ready to learn more about your fertility or discuss your family-building goals with a reproductive endocrinologist in Louisville, request an appointment with Fertility & Endocrine Associates for informed planning and care aimed at the best chance of a healthy baby.
