In this article, we explore how and why ageing affects fertility, offering insights into hormonal shifts, alterations in egg quality and quantity, and your reproductive health overall.

Quick facts:

• Ovarian reserve, cycling hormones and reproductive environment are all vital factors in female fertility. 
• Female fertility declines with age as our ovarian reserve diminishes. 
• Your 20s is when you’re most fertile until post 35 when fertility starts to decline more significantly
• The end of your reproductive years is marked by menopause.
• If you’re looking to conceive post 35, you may want to explore fertility treatments. 

Does age impact fertility?

Age is one of the biggest factors affecting female fertility. Although ageing is inevitable, how it affects your fertility is complex, and varies between individuals.

As women and those assigned female-at-birth (AFAB) age, their reproductive health undergoes various changes that impact conception, pregnancy, and childbirth. But how and why does fertility decrease with age, and what can we do about it?

Some of the most common questions we get at Hertility are, ‘What is the best age to have a baby?’, ‘What age does a woman stop being fertile?’ and ‘What are the chances of getting pregnant over 35 naturally?’

We’ll cover everything you need to know about fertility in your 20s, 30s, 40s, 50s and beyond, so you’re equipped to make informed family planning decisions as you navigate ageing and fertility.

Understanding female fertility and age

To understand how ageing affects female fertility we need to understand the basics of female fertility. 

Three factors—the quality and quantity of your eggs, your hormones, and your reproductive environment (uterus and fallopian tubes)—are what is needed to be in tip-top shape for a healthy pregnancy to occur. 

If one or more are out of sync, conception and pregnancy become more difficult. Let’s take a look at each.

Ovarian reserve

Women and AFAB people’s fertility is closely tied to the menstrual cycle. The average menstrual cycle lasts about 28 days, but it can vary. The menstrual cycle involves the release of an egg (ovulation) and the build-up of the uterine wall lining in preparation for a potential pregnancy.

We are born with all the eggs we’ll ever have. Our eggs are stored in our ovaries and this pool of immature eggs is known as your ovarian reserve. 

Each month, a couple of eggs from this pool start to mature, but only one egg is eventually released during ovulation. But here’s the thing: as you age, the quantity and quality of your eggs decline—they age too!

Cycle hormones

Hormones, particularly oestrogen and progesterone, play a crucial role in regulating the menstrual cycle.

Hormonal balance is therefore essential for the proper functioning of your reproductive system, but hormonal imbalances affect lots of people trying to conceive for reasons in and out of their control.

You can support your hormones with lifestyle adjustments like eating a well-balanced diet, regular exercise, managing sleep and stress, and limiting alcohol and smoking.

Reproductive environment

Your uterus provides a safe space for a fertilised egg to implant and develop into a foetus. The fallopian tubes transport the egg from the ovary to the uterus where fertilisation can occur (the first step of pregnancy). 

For a natural pregnancy to occur, your reproductive environment (like your uterus and fallopian tubes) must be in good condition too.

How age affects fertility in women

Our bodies are incredible, but unfortunately, as we age, there’s a time limit on our fertility. Wondering how fertility decreases with age?

For most, in your 20s and 30s, your reproductive health is in full swing and your eggs are super healthy. As you age, your eggs do too, which means there’s less available, and the ones there aren’t necessarily the best quality.

Your ovarian reserve can be estimated with an Anti-Müllerian Hormone (AMH) test, but it won’t tell you the quality of your eggs, only the number you have left.

Good-quality eggs are associated with better rates of fertilisation, improved embryo quality, and a higher chance of successful implantation (when the fertilised egg attaches to the womb lining to develop into a foetus, then a baby). Infertility issues, frequent miscarriages and in rare cases, genetic disorders like Down syndrome, can be down to poor egg quality.

As we age, our hormones change too. Your fertility hormone heroes, oestrogen and progesterone, can fluctuate and gradually decline over time, with the most significant dip at menopause.

Reproductive health conditions like polycystic ovary syndrome (PCOS) which can make your periods and ovulation unpredictable, thereby making getting pregnant difficult, is also the result of a hormone imbalance, especially androgens like testosterone.

Plus, as you age, you might experience health issues. Medical diagnoses, chronic health conditions, and autoimmune disorders can crop up as you get older. These can all prevent your hormones and the reproductive environment from working as they should.

At what age does fertility decline?

Female fertility typically peaks during the 20s and early 30s. During this time, the likelihood of conception is higher and the risk of miscarriage is relatively low.

One study by the Norwegian Institute of Public Health found that miscarriage was lowest among women aged 25-29 at 10%. This rose rapidly after age 30, reaching 53% for women aged 45 and over.

Female fertility starts to decline in the late 20s and more significantly after the age of 35. The quantity and quality of eggs diminish more rapidly, making it more challenging to conceive.

As we age, especially from our mid-30s, the decline in the ovarian reserve both in terms of quality and quantity happens very rapidly and the odds for conception and pregnancy become harder.

Menopause marks the end of your reproductive years, usually occurring between ages 45-55. During menopause—an inevitable part of ageing—your ovaries stop working, your hormones gradually decline, your menstrual cycle ends and you can no longer get pregnant naturally.

Females stop being fertile at menopause (not having a period for 12 months), however, fertility declines gradually with age, and after age 35, it becomes much more difficult to conceive and have a healthy pregnancy. However, it is important to note that this decline is unique to each person.

Fertility milestones by age group

You are most fertile in your 20s. Fertility gradually declines in the 30s, particularly after age 35. The chances of getting pregnant each month during your 30s are about 20%. 

That means that for every 100 fertile 30-year-old women trying to get pregnant in 1 cycle, 20 will be successful and the other 80 will have to try again. 

By age 40, the chance is less than 5% per cycle, so fewer than 5 out of every 100 women are expected to be successful each month.

Let’s break down fertility expectations and considerations across different age groups. Consider this your female fertility age chart.

Fertility in your 20s

In your 20s, you have the highest chance of conception and a healthy pregnancy. You have higher quality eggs and a higher quantity of eggs, making conception more likely. The risk of miscarriage and birth defects is also at the lowest it will ever be.

Prioritising overall health and well-being puts the wheels in motion for a healthy reproductive journey. Regular check-ups, a balanced lifestyle and contraception options (if you don’t want to become pregnant yet) are fertility considerations in your 20s.

The earlier you can start thinking about family planning, the better. Freezing your eggs early puts you in good stead if you know you want to have a baby in the future but aren’t quite ready for it right now. The younger you are when you freeze your eggs, the better chance of conceiving through IVF later down the line.

Fertility in your 30s

Your fertility chances are still high in your early 30s, but from your mid-30s onwards, there is a noticeable dip in fertility. 

Your ovarian reserve begins to decline, affecting both egg quality and quantity. While conception remains likely, complications like miscarriage and genetic disorders increase.

Want to increase your fertility in your 30s and 40s? Regular health check-ups, maintaining a healthy lifestyle and speaking with healthcare providers to discuss family planning options will be useful if you know you want to start a family.

The average age of a woman becoming a mother for the first time in the UK is 31. Most women and those assigned female-at-birth (AFAB) freeze their eggs and start in-vitro fertilisation (IVF) cycles in their 30s. 

A hormone and fertility test can give you an indication of your fertility so you can make informed decisions.

Fertility in your 40s

In your 40s, your fertility takes more of a decline and the risk of complications increases. Conception might take longer and the risk of miscarriage and chromosomal abnormalities like Down syndrome rises.

Speaking to healthcare professionals and consulting with fertility advisors is important during this period. You might have to explore alternative family planning options and fertility treatments like IVF, donor eggs or embryos.

Some fertility clinics have age limits to their services, but many work on a case-by-case basis to consider your health and medical history.
You might start to notice signs and symptoms of perimenopause in your late 40s and seek menopause treatment like hormone replacement therapy (HRT) to manage them.

Fertility in your 50s and beyond

Post 50, fertility significantly diminishes and conception may not be possible. 

Menopause marks the end of your reproductive years. Oestrogen and progesterone take a nosedive, and your ability to get pregnant reduces significantly over time until your periods stop altogether. The average age of menopause in the UK is 51.

There’s a much higher risk of infertility, miscarriage, and complications during pregnancy in your 40s, 50s and beyond. If you are still menstruating you might be recommended to consider options like donor eggs.

Planning for a family: age and fertility strategies

When it comes to family planning, the earlier you can explore your options, the better. Here are some strategies you may want to consider before you begin your conception journey.

Get regular health check-ups

Getting regular health check-ups is important if you want to start a family. The Hertility hormone and fertility test can give you insights into what’s going on with your reproductive health, along with a doctor-written report from a fertility specialist. Experts recommend getting one annually to stay on top of your reproductive health journey.

Consult with healthcare professionals

You don’t need to wait until you’ve been trying for a year without luck to consider a fertility evaluation or consult with a healthcare professional. The earlier you know, the better. 

Consider a hormone and fertility test and speak with a fertility advisor, especially if you’re over 35. Having open and honest conversations with healthcare professionals about your family planning goals can go a long way. They can provide personalised advice, discuss fertility options and guide you through the process.

Explore fertility treatments

If you haven’t been able to conceive naturally, or are in a same-sex relationship or exploring solo parenthood, you can utilise fertility treatments.

You might be recommended options like in-vitro fertilisation (IVF)—when an egg is removed to be fertilised outside the womb—or intrauterine insemination (IUI)—when sperm is placed directly into the uterus.

Consider egg freezing

If you’re not ready for parenthood but want to preserve your fertility, freezing your eggs, especially in your 20s and 30s, can be a proactive step to maintain the quality of your eggs for future use.

Maintain a healthy lifestyle

You can optimise your fertility naturally by eating well, exercising regularly and managing stress. Lifestyle factors can significantly impact fertility by affecting your hormones. Adopt healthy habits early on to contribute to your reproductive health and well-being.

Consider partner involvement

Fertility issues can affect anyone. One-third of infertility issues are because of male fertility, one-third to female, and one-third are unexplained or a mixture of both. Male fertility can also be influenced by age and health.

If you have a partner and are trying to conceive encourage open communication, ensure they get tested too and are working on keeping their health tip top. 

Fertility and age FAQs

How can I assess my fertility health as I age?

A hormone and fertility test, which involves a detailed health assessment that considers family and medical history, blood test, and a comprehensive doctor-written report can help you assess your fertility as you age. 

Regular health check-ups and a hormone and fertility test every year can ensure you’re on top of your reproductive health.

Are there lifestyle factors that can influence fertility with age?

Lifestyle factors that can influence fertility as you age include eating well, getting regular exercise, managing stress, and getting enough sleep. Stopping or reducing alcohol and smoking can make a big difference too. Healthy lifestyle habits support your egg quality, hormone balance, and reproductive environment for better fertility outcomes.

What fertility treatments are available for older women?

For older women, IVF offers the best chance of success in fertility treatments. In-vitro fertilisation (IVF) is when the egg and sperm are fertilised in a laboratory outside the body, and then placed back into the womb to develop into a baby. You might also be recommended to use donor eggs or embryos.

For same-sex couples wanting to become parents, intrauterine insemination (IUI), when sperm is placed directly into the womb, is available too. IUI is often the best option for people who can’t have vaginal sex, for example, because of a physical disability or psychosexual problem.

The most optimum time to consider egg freezing is usually late 20s to mid 30s, because the quality and quantity of eggs is better and can result in better outcomes, however, wanting to freeze your eggs in your late 30s or even 40s is not impossible, but you might need more cycles and outcomes may not be as good. Individual fertility clinics may also have varying age limits on offering fertility treatments.

How does menopause affect fertility

Menopause is a natural part of ageing and marks the end of your reproductive years. Gradually, your ovaries stop producing eggs and egg quality reduces (making it difficult to conceive), your menstrual cycle and periods stop and you can no longer become pregnant, but it’s not an overnight change.

Your fertility declines gradually as we age with a significant dip in hormones, oestrogen and progesterone, usually in your late 40s and early 50s. You might start to experience perimenopausal symptoms like hot flashes, irregular periods and mood swings, which are a result of the hormone shift happening inside. 

Menopause is confirmed when a woman hasn’t experienced a period for 12 consecutive months. At this point, fertility is essentially non-existent as ovulation ceases and the ovaries are no longer releasing eggs.

Advanced maternal age is linked to an increased risk of chromosomal abnormalities in eggs. This raises the likelihood of miscarriage and birth defects in pregnancy too.