Guide to Antral Follicle Count

When a woman is born, she is born with all her eggs inside her ovaries. Follicles are found in ovaries and are small fluid-filled sacs that help eggs mature. During an ovulation cycle, the follicle sack bursts, and the mature egg is released. 

Follicles go through various stages and the higher the antral follicle count, the better the eggs. As you can see, follicles are important in the IVF process. 

Key Takeaways

• Follicles develop in groups during the menstrual cycle, but ultimately only one reaches full maturity and releases an egg during each cycle.
• Antral follicles are small, fluid-filled sacs with eggs inside them that grow on the outside of ovaries, eventually rupturing and releasing an egg during ovulation.
• Age is a major determinant of how many follicles grow and become viable in each cycle, but certain medications can stimulate follicles and increase the number reaching maturity at once.

What Is an Antral Follicle Count?

An antral follicle count focuses on an individual’s antral follicles. These antral follicles are small, fluid-filled sacs found outside the ovaries. They contain immature eggs also known as oocytes or immature eggs. 

During your monthly cycle, several follicles, start to mature. However, only one egg matures completely and this egg is successfully released during ovulation.  The number of antral follicles that mature differs among women. 

The antral follicle count is a great fertility indicator for ovarian reserves and studies have proved this. For those hoping to conceive, understanding this count is the first step in knowing when you should start your pregnancy journey. This is also coupled with the fact that one’s AFC reduces with age and the older one grows the fewer the follicles produced and the lesser the chances of becoming pregnant.  

The AFC also affects one’s in vitro fertilization (IVF) journey as it can also factor in on how well the treatment takes. Understanding your AFC will also help your healthcare provider curate a fertility treatment for you. 

How To Test The Antral Follicle Count (AFC)

The antral follicle count (AFC) test determines the number of follicles in the ovaries also known as one’s ovarian reserve. The AFC test provides great insight into a woman’s fertility outside of the quality of eggs or physical well-being.  Using the AFC test, fertility centers like  Ivy Fertility can diagnose diseases like polycystic ovary syndrome (PCOS) and provide insight into how successful an assisted reproduction technology treatment will be. 

To perform the test, the fertility specialist will insert an ultrasound into the vagina to get a clear picture of your ovaries, especially the development and number of your antral follicles. This is called a transvaginal ultrasound that’s done during the third day of your menstrual cycle and it’s a relatively painless procedure. 

What Is A Normal Antral Follicle Count?

A healthcare professional should be able to determine whether your AFC is normal or not. The total AFC is the sum of the antral follicles in both ovaries. For most women, 12 to 24 follicles are considered normal and a “normal” AFC ranges between 3 and 30 follicles. However, several factors affect this count, age being one of them. 

It’s normal for the count to vary between ovaries. This uneven distribution is no cause for concern as long as the total count is within the normal range. Though you can’t naturally increase your AFC count, lifestyle changes can improve the overall health of your eggs. 

Normal Antral Follicle Count By Age:

As already mentioned, age is essential when looking at the AFC. AFC has been shown to decrease with age, with an accelerated decline in the late 30s. A study conducted on women aged 25-46 years found an average AFC decline of around 5 percent for individuals under the age of 37, with that decline increasing to almost 12 percent in the following years.

• 20-24 years: 12-30 follicles
• 25-34 years: 13-25 follicles
• 35-40 years: 10-15 follicles
• 41-45 years: 3-10 follicles
• 46+ years: 0-3 follicles

While age is important, it is not the sole determinant. An individual’s overall health and genetics also play a role. 

Does Low Antral Follicle Count Result in Infertility?

A low AFC indicates a low ovarian reserve. In fact, women with Polycystic Ovary Syndrome (PCOS), can have a high AFC because PCOS can cause an increase in small antral follicles. However, this doesn't translate to egg viability. However, this doesn’t automatically mean infertility. Women with low AFC can conceive naturally or with the help of treatments like IVF.

What’s The Best AFC For IVF?

In IVF treatment, your follicle count plays a key role. During IVF, one’s follicles are stimulated to reach maturity so that there’s an increase in the likelihood of successful fertilization. One study found individuals with higher AFC numbers were more successful in their IVF cycles overall, but also found AFC data could provide valuable insight for how to proceed with fertility treatments regardless of how many follicles were present during a given menstrual cycle.

This differs from then intrauterine insemination (IUI ) treatments that only need one healthy follicle for a pregnancy to occur. On the other hand, IVF involves retrieving eggs from the ovaries before fertilization. This means the treatment needs a higher number of follicles, aiming for the 10 to 15 range. Although an IVF round requires these numbers, successful treatments are possible with numbers outside this range. This makes multiple pregnancies a high possibility in IVF as opposed to IUIs. Additionally, any extra eggs can be preserved for future use. 

Bottom Line

The Antral Follicle Count or AFC is one of the best ways to assess an individual’s fertility. This count decreases with age. However, a low AFC does not necessarily mean a healthy pregnancy is impossible. Many women have conceived naturally despite tests indicating a declining AFC. 

Even more, fertility treatments like IVF have proven to be very successful for many couples and individuals struggling with fertility difficulties. If you are trying to become pregnant or are planning to in the future, an AFC test could provide valuable insight into your best steps forward toward those goals.