May 10, 2024
8 Minutes

Your Guide To Antral Follicle Count and Egg Freezing

Your Guide To Antral Follicle Count and Egg Freezing
Written by
Navya Muralidhar
MSc Clinical Embryology & Embryologist
Amilis makes fertility digestible, accessible, and affordable to help you take charge of your reproductive health and live on your own timeline.

In an eggshell...

  • Your antral follicle count is a way of measuring how many eggs you might have left in your ovaries.
  • It's a quick, painless transvaginal scan that allows your healthcare specialist to get a view of your ovarian health, as well as number of follicles present.

Our bodies have a way of telling us things 🥸

Especially with our reproductive health, our ovaries have little messengers that let us know the situation at ground zero, or the ovarian reserve. 

And these two messengers happen to be AMH (Anti Mullerian Hormone) and AFC (Antral Follicle count).

AMH is on the hormonal end and lets us know if our egg count is appropriate for our age, via a simple blood test. On the other hand, AFC is an ultrasound test, where we get a visual sneak peek into the number and growth of follicles in the ovary.

Now, why is this important? 

As we age, we go from having millions of follicles in our reserve to a declining trend in number and quality of eggs as we hit our 30s and 40s. 

This is where AFC comes in. Knowing your ovarian reserve can help you understand your reproductive health, plan better, or even preserve your fertility if needed. 

So, let’s dive into understanding AFC better, with this simple guide!

What is Antral Follicle Count?

The Antral Follicle Count (AFC) refers to the number of small fluid-filled sacs (antral follicles) present in your ovaries at a particular time. 

Here’s the backstory: For our menstrual cycle to happen, our ovaries start at the first step by recruiting a group of follicles for the month, in a race to crown the “mature egg of the month” 👑 

These follicles each house an immature egg, and their number indicates your remaining egg supply

They grow in response to hormones such as FSH and LH, nourishing and growing the egg inside as well.

A higher AFC generally suggests a larger pool of eggs, while a lower count might indicate a smaller reserve.

How is AFC measured?

Measuring your AFC is a relatively simple procedure. Compared to an AMH blood test, AFC is measured using a transvaginal ultrasound. 

During the scan, the sonographer uses a specialised probe inserted into the vagina to visualise your ovaries and count the visible antral follicles. 

Why this, you ask?

The probe emits ultrasound waves, which help obtain a clearer image of the ovaries. 

This typically takes less than 15 minutes and can be performed in a doctor's office or an ultrasound clinic.

It’s better to know beforehand that while this procedure may cause mild discomfort, it shouldn’t be painful.

When is AFC usually measured?

The time at which AFC is measured has a lot to do with their size. 

An AFC test can be done at any point in your menstrual cycle, but it's often recommended during days 2-4 of your menstrual cycle.

Around this stage of the menstrual cycle, follicles are usually at a size of 3-10mm. Which, in a way, is at its immature stage 👶. Follicles which are nearing the mature stage, will be around 16-22mm.

As we age, the number of 3-10mm follicles decreases (due to age-related decline in the number of eggs) but the mature ones remain constant.

Hence, measuring your AFC on day 3 of your menstrual cycle (done most often!) or anytime between days 2-4 is a more accurate representation of your AFC.

AFC and egg freezing: What’s the connection? 

Egg freezing, also known as oocyte cryopreservation, is where your eggs are retrieved, frozen, and stored for future use. Along with an AMH test, doing an AFC test prior is crucial as it can help you understand these factors:

  • Response to egg freezing cycle: AFC is a key determinant of how your follicles grow in response to medication given during egg freezing cycles. AFC even correlates with the number of eggs retrieved, making it an informative report for doctors to tailor stimulation protocols and medications accordingly.
  • Choosing the right protocol: Based on your AFC, your doctor can tailor the stimulation protocol for egg retrieval. This ensures you receive the optimal dosage of medications to stimulate your ovaries and maximise the number of mature eggs retrieved.
  • Determining the best timing: AFC can also help you decide the ideal time to freeze your eggs. Ideally, egg freezing should be done when your ovarian reserve is still good, offering a better chance of retrieving a sufficient number of healthy eggs.
  • Risk of OHSS: Taking an AFC test can act as a predictive tool prior to your egg-freezing cycle. Studies have shown how AFC levels of >24 can be a predictor of moderate to severe OHSS. This way, healthcare providers can be more vigilant of your response in the egg-freezing cycle and tailor protocols to reduce the risk of OHSS.

What else does an AFC test tell you?

Besides the context of egg freezing, an AFC test can also provide insights into other aspects of your reproductive health, such as:

  • PCOS (Polycystic Ovary Syndrome): Women with PCOS often have an elevated AFC due to the presence of numerous small follicles. However, these follicles might not necessarily contain mature eggs.
  • Ovarian reserve: A low AFC can be an indicator of diminished ovarian reserve, suggesting a lower potential for spontaneous pregnancy or a lower response to fertility treatments like IVF.

What are normal AFC levels by age?

Here’s the thing: AFC is just one piece of the puzzle. While a general guideline exists, individual variations are way more common. 

For instance, someone in their 20s may have a higher AFC, but if someone in the same age group has a low ovarian reserve due to genetic factors, they may have a lower AFC. Hence, variations based on heredity and overall health is to be factored in.

Here's a simplified chart that lets us know the average AFC ranges by age:

Age Group Average AFC Range
20 - 30 15 - 35 follicles
30 - 35 11 - 25 follicles
35 - 40 6 - 15 follicles
40+ Less than 6 follicles


I have low AFC, can I freeze my eggs? 

Yes, you can still freeze your eggs even with low AFC. However, it's essential to discuss your options with your doctor. They might suggest:

  • Freezing at a younger age: If possible, consider freezing your eggs sooner when your AFC is likely to be higher.
  • Utilising a different stimulation protocol: Your doctor might adjust the medication dosage or use different types of protocols for egg pooling, and so on, to optimise egg retrieval even with a lower AFC.
  • Considering alternative options: Exploring options such as donor eggs might be discussed based on your situation and preferences.

What does a high AFC mean?

Having a high AFC typically indicates a good ovarian reserve, with a higher chance of obtaining eggs and a good ovarian response. However, it's equally important to discuss this with your doctor, as it could also be associated with:

  • Ovarian hyperstimulation syndrome (OHSS): This is a potential side effect of fertility medications, and your doctor might adjust the protocol to reduce exaggerated ovarian response or choose alternate options such as IVM (In Vitro Maturation) + egg freezing to minimise the risk of OHSS.

How much does an AFC test cost?

The cost of an AFC test can vary depending on factors like your location, insurance coverage, and the clinic.

Cost of an AFC Test in the UK and London:

The cost of an AFC test in the UK and London can range from £100 to ££250 depending on the location and services included (consultation, report, etc.). Here is a breakdown:

  1. Location: Costs can differ slightly between different regions in the UK.
  2. Clinic: Costs can vary depending on the clinic offering the test. Additionally, follow-up consultations to understand the results of the AMH test also add on to the costs.
  3. Insurance coverage: If you have private health insurance, it might cover the cost of the AFC test partially or fully. Always check with your insurance provider for specific coverage details.

It's important to remember that these are just estimated ranges, and the actual cost might differ. To get the most accurate information, it's highly recommended to:

  • Contact the specific clinic or hospital you're considering for the test and inquire about their current charges.
  • Check with your GP or healthcare provider for guidance and potential referral options within the NHS system, You can also read our guide to check whether you’re eligible for egg freezing on the NHS.

By exploring these options, you get a clearer picture of the associated costs and this can help you make an informed decision about where to get your AFC test.

Save on your egg-freezing costs, with Amilis 

With all the humdrum around egg freezing, it can often come across as a luxury treatment or a pricey reproductive choice.

But we’re here to tell you that it doesn't have to be. 

At Amilis, we worked to identify the gaps and stages where we could make the procedure cost-effective, while partnering with the best, vetted clinics in the UK that provide egg freezing.

This includes a clinic comparator that helps you choose the best egg-freezing clinic in London, and opt for free consultations, otherwise worth £250. This makes the conversation around AFC and getting a test much more accessible, and affordable. 

Plus, our free platform has all the resources you need, from articles on egg freezing, to a calculator that helps estimate success rates. 

We’re making egg-freezing accessible and affordable, one step at a time! Try our personalised quiz to get started today!

Written by
Navya Muralidhar
MSc Clinical Embryology & Embryologist

An embryologist by degree, and an educator by heart, Navya has completed her Bachelors in Genetics, and her Masters in Embryology and now strives to deconstruct the complex, into educational and informative articles surrounding her field of interest. She's specifically focused on time-lapse technology, IVM, and pre-implantation genetics. When not writing, you can find her at her favourite or newest coffee shop in town, sketching away, or listening to a podcast.