Age is one of the most common questions people in Melbourne have about fertility. It can influence your chances of conceiving because both egg number and egg quality change over time. Understanding how these changes happen can give you useful context when thinking about your fertility now or planning for the future.
In this article, we look at how age can affect fertility, how fertility changes over time and what options you may want to consider if future fertility is on your mind. For a broader look at the different factors that can influence your chances of conceiving, see our guide to factors affecting fertility.
Why Age Affects Fertility
Women are born with all the eggs they’ll have, around one to two million at birth, reducing to roughly 300,000 to 400,000 by puberty. Egg numbers continue to decline over time, and egg quality changes too. As eggs age, they’re more likely to have chromosomal (DNA) changes, which can affect fertilisation, increase the chance of miscarriage and reduce the likelihood of an ongoing healthy pregnancy.
Male fertility also changes with age, although this tends to happen later and more gradually. Sperm is produced continuously, so there isn’t the same decline in a fixed reserve. From around the mid-forties, changes in sperm quality, including movement and DNA integrity, can become more common and may influence fertility.
Fertility Decline by Age: The Timeline
Fertility changes gradually with age, and the rate of change isn’t the same throughout your reproductive years. For many women, the decline becomes more noticeable from the mid-thirties and continues as you get older.
- Late teens to late 20s: Fertility is generally at its highest, for both egg quantity and quality.
- Early 30s: Decline begins, but gradually. Many women in their early thirties conceive without difficulty.
- Mid-30s (around 35): Changes in egg number and quality become more noticeable with age. Chromosomal changes in eggs also become more common.
- Late 30s (37 to 39): Fertility continues to change with age. It may take longer to conceive and the chance of miscarriage increases as egg quality changes over time.
- 40 and beyond: Chances of conceiving naturally continue to decrease with age. Pregnancy after 40 is still possible, although it may take longer to conceive and some people may benefit from fertility assessment or treatment.
- Men, from the mid-40s: Sperm quality begins a more gradual decline, with measurable effects on time to conception.
These are population trends, not individual guarantees. Some women in their twenties have lower-than-expected egg reserve, and some in their late thirties conceive easily. The only way to know where you personally stand is through testing.
What This Means in Practice
- Time to conception can increase, as changes in egg quality mean the chance of conception in each cycle gradually decreases.
- Miscarriage becomes more common with age, partly because chromosomal changes in eggs are more likely.
- Your response to fertility treatment can also change. Ovarian reserve influences how the ovaries respond to stimulation and the number of eggs that may be collected.
- Your options may change over time as egg number and quality continue to decline. Understanding where your fertility stands can help you make decisions with more information and in your own time.
Knowing Where You Stand
Age-based averages can give you useful context, although they can’t tell you exactly what your fertility looks like. A fertility health check can provide a more individual picture, which may include an AMH blood test and pelvic ultrasound for women and a semen analysis for men.
You may consider testing if you’re trying to conceive, thinking about your future fertility or want more information before making decisions about timing. If you have irregular cycles or a family history of early menopause, you may also find it helpful to understand when to see a fertility specialist.
Fertility Preservation: Protecting Your Options
Understanding how fertility changes with age can lead to another question: can you preserve your fertility for later? Fertility preservation in Melbourne most commonly involves egg freezing, which some people consider when their plans for pregnancy don’t align with their current circumstances, including career, relationships or medical treatment.
The process involves ovarian stimulation to develop multiple eggs, followed by egg collection and freezing. Age at the time of freezing is an important factor in future success because egg quality changes over time. Eggs frozen at 30 generally have a higher chance of resulting in a future pregnancy than eggs frozen at 38. Understanding this earlier can give you more information about your options, even if you’re unsure whether egg freezing is right for you.
Sperm freezing is the equivalent fertility preservation option for men and may also be considered before medical treatments, such as chemotherapy, that could affect future fertility.
When to Seek Advice
- You’re over 35 and have been trying for six months without success (twelve months if under 35).
- You want children eventually but aren’t ready yet and want to understand your preservation options.
- You have a family history of early menopause or a condition that may affect ovarian reserve.
- You’re facing medical treatment that could affect fertility.
- You simply want clarity before making decisions about timing.
None of these require you to have already decided on a next step. A conversation with a specialist is about getting accurate information.
Your Next Step
Age is the strongest predictor of fertility, but it isn’t the only piece of information that matters, and it doesn’t mean your options are fixed by a birthday. At Create Fertility Melbourne, our specialists can assess your individual fertility and talk through options, including preservation, that suit your circumstances. Book a consultation with our team for a clearer picture of where you stand.
Frequently Asked Questions
At what age does female fertility start to decline?
Gradually from the late twenties, more noticeably from around 35, and faster again from 37 to 39.
Does male fertility decline with age too?
Yes, though later and more gradually. Sperm quality typically starts to decline from the mid-forties.
Is 35 really a meaningful cutoff?
It’s not arbitrary, but it’s not a hard line either. Research shows a measurable acceleration in decline around this age, which is why it’s used as a guide for earlier testing. Individual fertility still varies.
How do I know if egg freezing is worth considering?
It depends on your age, timeline, and personal circumstances. Testing your ovarian reserve gives a clearer picture, and a consultation can help you weigh it up.
Can fertility testing tell me exactly how many years I have left to conceive?
No. Tests like AMH and antral follicle count show current ovarian reserve relative to age, which guides treatment decisions, but they can’t forecast an exact personal timeline.
