Antral Follicle Count

Antral follicles are fluid-filled sacs inside which the eggs produced by ovaries develop and grow before they are released during ovulation. Everyone produces an uncertain number of follicles in any cycle, but this number matters in assisted reproduction treatments. 

Antral Follicle Count

Antral follicle count is central to a person's ability to conceive naturally. Antral follicles typically develop in groups, but only one of them reaches full maturity in a typical menstrual cycle. 

For assisted reproduction treatment to be successful, having more than one egg to work with increases those chances. Therefore the viability of a person’s antral follicles matters. There are some factors that affect the potential number of follicles that will be produced during treatment, as well as their quality. These are:

Age

Because the number of follicles decrease with age, a person’s chances of becoming pregnant also become more slim with each cycle, even as the quality of eggs declines.

Health

A person’s health physically, which includes their lifestyle, Body Mass Index (BMI), tobacco, drugs, or alcohol use, all contribute to the health, quantity and quality of their antral follicles.

Medical History

Disease and medical conditions contribute to the viability of one’s antral follicles.  Hypertension, periodontal disease, chlamydia, PolyCystic Ovary Syndrome (PCOS), and endometriosis have a negative effect. Those who have undergone chemotherapy or radiation treatments can sometimes become infertile altogether.

The Antral Follicle Count (AFC) Test

An AFC test is used to determine an estimate of the quantity of oocytes a person has in their ovarian reserve. This is then used in making a decision about the most suitable assisted reproduction treatment for that person.

A transvaginal ultrasound is used to capture images of the ovaries which are sent to a specialist for interpretation. With this information, professional healthcare practitioners can assess how one’s AFC compares against normal ranges.

Normal Vs. Abnormal AFC

A study showed that  by the time someone is 37 years old, there has been on average a five percent annual decline in the production of antral follicles, which more than doubles thereafter.

Another study found that those people who naturally had a higher number of antral follicles tended to produce a higher number of eggs during ovarian stimulation when undergoing assisted reproduction treatments.

Generally AFC estimates by age are as follows:

Follicles and Menstruation

The follicular phase of a menstrual cycle begins right after the end of menstruation and lasts about two weeks. This is the time that antral follicles begin their development, mature and are released.

The phase where a mature egg is released is called ovulation and usually takes place roughly about two weeks before a period. The egg is typically fertilized during ovulation, leading to pregnancy. 

The time within which antral follicles develop and mature also determines the time a person can get pregnant. Because the exact moment a follicle matures and is released remains a mystery, pregnancy is possible outside of the ovulation window.

Follicles in Fertility Treatments

To increase the chances of positive pregnancy outcomes, fertility treatments tend to retrieve more than one mature egg. Therefore the ovaries are stimulated to develop and bring more follicles to maturity using hormone injections and oral medications. 

Intrauterine Insemination (IUI)

Although IUI treatments usually require one mature follicle, more than one follicle could mature during ovarian stimulation. Therefore another AFC test may be done before treatment begins to be sure.

Multiple pregnancies can happen using IUI, but if there are more than three mature follicles, the procedure is typically cancelled to prevent risks during pregnancy. 

In Vitro Fertilization (IVF)

AFC test results are used to determine how the hormonal phase of IVF treatment will proceed, because about 10 - 15 follicles are usually required per round. Therefore stimulating multiple follicles gives individuals a larger number of eggs for immediate fertilization or freezing for future use.

To Conclude

Pregnancy cannot occur without antral follicles because they determine a person’s fertility. Incidentally, a low AFC does not mean a person cannot become pregnant, rathee, the health of the follicles one has is more crucial. 

Frequently Asked Questions (FAQs)

What is a transvaginal ultrasound?

A transvaginal ultrasound is a medical imaging procedure that uses a wand-shaped ultrasound that is inserted into the vagina, to capture images of the pelvic cavity, uterus, fallopian tubes, and ovaries.

Is IVF better than IUI?

Considering the multifaceted factors that go into such a decision, it is advisable to consult a professional healthcare provider to determine the best treatment plan for you.

Why is my AFC low?

AFC results are influenced by many factors but your healthcare provider is best placed to elaborate on the specific ones that may have contributed to your low AFC. Additionally, they can also advise you on what you can do about it.

Can I increase my AFC?

Not really. You see, the number of follicles your body produces is unique to you. Hormonal treatments used in assisted reproduction do not increase this. What they do is to increase the number that reach full maturity, out of those produced naturally.