Screening tests for female fertility and remaining egg supply - ovarian reserve
Testing women in the general population for egg supply
This page focuses on tests of female fertility potential that might be useful in the general population. This page is not directed at infertility patients. Other pages on this site deal more extensively with specific fertility tests and issues for infertile women, such as:
Background on remaining fertility potential in women
For the most part, women go through life without any knowledge at all about the status of their remaining fertility potential. Many women put off trying to get pregnant until a convenient time in their lives, and by the time the "right time" comes, their fertility potential might be reduced - or already gone forever.
Female age is a variable that is often used by physicians (and others) to counsel women regarding the question of when they should "get going". Age can certainly be helpful in this regard, but chronological age is only one variable. Some women are still fertile at 42 (very few), while others (very few) are in menopause - and completely out of eggs - at age 25.
We have some screening tests that are supposed to help answer these questions, but they aren't perfect.
Antral follicles are small follicles (about 2-8 mm in diameter) that we can see - and measure and count - with ultrasound. Antral follicles are also referred to as resting follicles. Vaginal ultrasound is the best way to accurately assess and count these small structures.
Many fertility specialists believe that the antral follicle counts (in conjunction with female age) are the best tool that we currently have for estimating a woman's remaining fertility potential (or ovarian reserve). Ovarian volume measurements (also done by ultrasound), and day 3 FSH and AMH levels (blood tests) are additional studies that can help.
Presumably, the number of antral follicles visible on ultrasound is indicative of the relative number of microscopic (and sound asleep) primordial follicles remaining in the ovary. Each primordial follicle contains an immature egg that can potentially develop in the future.
In other words, when there are only a few antral follicles visible, there are far less eggs remaining as compared to when there are many more antral follicles visible. As women age, they have less eggs (primordial follicles) remaining - and they have less antral follicles visible on ultrasound.
Normal ovarian volume and "normal" antral follicle counts
Ultrasound image of an ovary at the beginning of a menstrual cycleThe ovary is outlined in blueThere are 9 antral follicles visible - marked with red dots Good antral count, and good ovarian volume
Low ovarian volume and low antral follicle counts
Ultrasound image of an ovary at the beginning of a menstrual cycle The ovary is outlined in blue Only 1 antral follicle is present - red dot Very poor antral count - and very low ovarian volume
How many antral follicles is "good"?
There is not a perfect answer to this excellent question. Unfortunately, we do not live in a perfect world, and some ovaries have not yet read up on antral follicle counts. However, the table below gives some ideas, based on our experience using antral follicle counts on thousands of women for over 10 years.
In my experience, here are some general guidelines:
|Total number of antral follicles||Expected
fertility potential for women
under about 37
For 37 and older we need to be more cautious - low antrals and late 30's or early 40's is significantly worse
|Less than 4||Extremely
High risk of poor fertility potential.
Fertility issues are very possible - either soon, or within several years.
It is possible that some fertility issues are already present.
We are concerned about fertility issues sometime in the future. It appears that the clock is ticking faster than we'd like.
of the average range.
We are not worried yet. However, as antral counts drop over time, fertility issues may develop.
Expect excellent fertility potential. At least for now, the clock seems to be ticking at a normal rate.
How can women get an antral follicle count test done?
It might not be easy, depending on where you live. The test has been in use since about 1998. Currently, antral follicle counts are being performed by some (? most) fertility specialists (including us). Very few gynecologists or radiologists are performing the test.
Eventually, I believe that this test will be taught to physicians in other fields of medicine (OB/GYN, Radiology, etc.) and could become a standard part of the annual exam performed on women - along with her breast exam, Pap smear and general physical exam.
Instead of her OB/GYN telling her, "Don't worry, you're only 33, you have lots of time left to have babies", she could be told, "You have 20 antral follicles, and that combined with your age of 33 predicts that your fertility potential at this time is still looking good.s
Dr. Sherbahn's recommendations for fertility screening in women that have not yet tried to get pregnant
- Have day 3 FSH and estradiol and AMH blood tests done
- If you can get antral follicle counts done - do that too
- If you are 37 or older and "don't have a man" and want to have kids someday - start looking over the guys - there are a few good ones out there
- If you are 37 or older and do have a (willing) man and want to have kids someday - consider getting going soon.