The science behind ovarian reserve testing

Reviewed by Health Guide Team, 

Written by Afton + Carly 

Reviewed by Health Guide Team, 

Written by Afton + Carly 

last updated: Mar 21, 2018

7 min read

The science of fertility is complicated–and it’s about time that it gets mainstream attention. At Modern Fertility, we’re dedicating our lives to decoding this science–analyzing peer reviewed studies with reproductive endocrinologists (fertility doctors), OB/GYNs, lab clinicians, and reproductive psychologists while accelerating fertility research of our own. Modern women deserve to know how fertility science is progressing and how to use it to inform decisions.

“Knowledge is power and I fully believe Modern women should be empowered with more knowledge about their fertility status,” Dr. Eric Forman, Medical and Lab Director at Columbia University tells us.

Modern women also deserve to understand the limitations of ovarian reserve testing. Our first step to making the right fertility information more available and personal is to make this testing more accessible for women–much earlier in life. Reproductive Endocrinologist and Fertility activist Dr. Aimee Eyvazzadeh tells us,

“We need to treat fertility like a medical issue, de-stigmatize it, and offer everyone fertility screening. With a little bit of education, women can use science to inform their family planning decisions and do what's extremely personal and right for them.”

Modern Fertility

Fertility hormones shouldn’t be a mystery

What is ovarian reserve testing?

There are simple hormone blood tests–specifically AMH and FSH + E2–that can measure ovarian reserve (or, how many eggs we have left). Kind of cool right?! These hormone levels can give us a better sense of our fertility timeline, egg freezing and In Vitro Fertilization (IVF) outcomes, future red flags, and menopause onset, than just age.

AMH, or Anti Mullerian Hormone, is a hormone produced by cells inside our follicles (the little sacs that hold our eggs) that serves as a proxy for the amount of eggs we have left. The level of AMH our follicles create reflects the number of eggs we have “waiting in the wings.” FSH or Follicle-Stimulating Hormone (which is often tested with E2 or Estradiol), supports maturation of the follicle. If the body needs high levels of FSH to kick-start this maturation, it may be a sign of low ovarian reserve.

These tests have traditionally been used by reproductive endocrinologists to understand potential outcomes for egg freezing and IVF and to determine how much the ovaries need to be stimulated to collect eggs for each procedure. When we have broader access to this testing we have more data for decision-making.

Dr. Aimee tells us, “We need to get ahead of infertility and regular fertility screenings are the simple action step we can all take. Much like we get checked for cervical or breast cancer, the same preventative tests can be done to assess our fertility levels.”

What can ovarian testing tell us?

We Modern women need more information than just “can I get pregnant right now?” When tracked over time, this testing helps us understand our fertility timelines–which are as unique as our metabolisms. Ovarian reserve testing is also valuable in understanding when we’ll reach menopause and in assessing egg freezing and IVF outcomes. Let’s break these down.

Menopause onset

AMH can help us understand the likelihood of reaching menopause earlier than average. Doctors use high levels of FSH over a long period of time (along with the end of a period and other clinical factors) to confirm menopause and AMH levels are highly correlated with menopause timing. Studies also show that AMH is a better predictor of the age we'll hit menopause than the age our mothers hit menopause. If we have a lower ovarian reserve than average we could hit menopause earlier than the average age of 51 in the US. It’s important to note, however, the effects of menopause may start around 35. For many who have a first child before age 35, this isn’t an issue for baby number one. But if we are trying for a second or third baby at 38 or 39, it’s important to know what our menopause windows look like. AMH can help us understand the likelihood of reaching menopause earlier than average and therefore understand that window.


AMH testing can also play a role in detecting other reproductive issues like PCOS–a hormonal disorder that can cause irregular cycles and other symptoms. PCOS is associated with high AMH and can have major implications for fertility if left untreated. This testing can help us detect it earlier.

According to Modern Fertility's Dr. Erin Burke, “PCOS is the most common endocrine disorder in women. It’s been estimated that up to 15% of American women have PCOS. Testing and identifying PCOS can help us make decisions and seek treatment to prevent subfertility and poor pregnancy outcomes.”

IVF and Egg freezing

Egg count is directly correlated with success in egg freezing and IVF (and therefore increasingly important for the Modern woman). Today, with almost 1:6 couples having trouble getting pregnant and women waiting until later in life to have kids, more women than ever are debating whether or not egg freezing is right for them.

“Enabling patients to monitor their ovarian reserve will help patients and providers identify individuals who would benefit the most from fertility preservation, but ideally before their chances of success with IVF diminish significantly,” Reproductive Endocrinologist, Dr. Jonathan Kort tells us.

Outcomes with these procedures are tied directly to the amount and quality of eggs that a doctor can collect on any given cycle of treatment and AMH and FSH can help us understand the expected number of eggs that can be retrieved. Women with higher ovarian reserve are more likely to produce more eggs for collection. Dr. Kort also explains that this testing can, "help women tailor their ovarian stimulation to get the best results possible.”

Tracking and identifying red flags

Although one snapshot of ovarian reserve testing can be helpful, tracking these hormones over time can really help us get a better sense for future fertility than just checking in once. They can also help us screen for red flags that can have serious implications for fertility. Primary Ovarian Insufficiency (POI), the early loss of ovarian function, affects 1 in 100 women. POI occurs when a woman’s reserve of eggs are depleted at an early age (usually before 40) or when her ovaries are dysfunctional. Both these factors could lead to premature menopause and infertility. It's important to note that some women with POI may still ovulate.

FSH and, increasingly, AMH are used to diagnose POI. AMH is a particularly useful marker for POI because it is secreted by developing follicles, and thus levels of AMH correspond proportionally to ovarian reserve. Low AMH is a red flag for POI because it could indicate that one has fewer eggs than average. A simple AMH blood test can help identify if someone is at risk for POI earlier in life. AMH levels can also predict the chances of a live birth for women with POI.

Both POI and DOR, Diminished Ovarian Reserve, can greatly impact the likelihood of a healthy pregnancy, egg freezing and IVF outcomes, and can have implications for bone, heart and sexual health throughout a woman’s lifetime. Early detection is essential for proactive treatment and planning.

What can’t ovarian reserve testing tell us?

It’s also important to understand that these tests do not give us the whole picture. Ovarian reserve testing can’t tell us the chances of getting pregnant right now (or this month) and hormones are one part of fertility. Modern Fertility is focused on helping women understand all of these factors including what ovarian reserve can and cannot help us understand.

That’s partially because ovarian reserve testing does not give us insight into egg quality or how normal and healthy eggs are. The percentage of normal eggs we have is related to age. When we’re under 35, most of our eggs (even if there are fewer of them than average) will likely be healthy. As we get older and eggs become abnormal, there are fewer normal eggs to choose from. In other words, the chance of getting pregnant “right now” is more a factor of whether the egg we are ovulating “right now” is healthy than how many “total” eggs there are. After all, we just need one healthy egg and one healthy sperm.

Making AMH and FSH testing more accessible is a big responsibility because the results need proper interpretation within the context of our general health (after all, fertility is a complex puzzle with many pieces: our eggs–both quality and quantity– our partners, our lifestyle, and our general health). Whether we’re discussing with our friends or our doctors, the results of these tests should never be seen as a “magic 8 ball” for fertility prediction. They can serve as an important data point in thinking about fertility and overall health–a data point that women can choose. With Modern Fertility, information about fertility timelines, menopause onset, and success in egg freezing and IVF is more accessible for women, earlier in life.

The bottom line

We are thrilled to see more research into the utility of ovarian reserve testing but we still have a long way to go. A 2017 paper validates what we've explained above: that a single snapshot of AMH is not a pregnancy predictor–especially under the age of 35. Other physicians have pointed out, however, that this study has shortcomings and that ovarian reserve still may be associated with reduced odds of conception as women get older. The 2017 study does not track outcomes like miscarriage or live birth (only pregnancy), it only included a small number of women over 35 with low AMH, it excludes women with fertility problems that ended participation in the study to pursue fertility treatments, and it measures a snapshot of AMH instead of tracking AMH over time. It’s a great first step, but the bottom line is: we need more research that tracks healthy women throughout their lives in order to understand every nuance of fertility. Hormone testing provides valuable data points that can help us understand how our fertility changes over time.

“Right now in my practice, I see women come in wanting to get pregnant in their 40s,” says Dr. Aimee. “Many of them feeling like they're standing at an ‘egg cliff’ wondering why no one taught them simple tests they could have done to track something that's extremely precious, something that time takes and will never give back.”

Today, we Modern women need more information than just odds of conceiving right now. We need support understanding how we might respond to fertility treatments like egg freezing and IVF. As we wait longer to have our first child, we need support in planning our second...and our third child around menopause onset. We need data to track over time to help us understand our fertility in the context of our overall well-being.

“I hope that by tracking fertility results over time and developing these fertility ‘curves’ that Modern Fertility will help advance our understanding of natural fertility and how it changes over time,” says Dr. Forman.

With a singular focus on guiding women through the science of fertility, Modern Fertility is committed to supporting these very Modern needs so women can make the decisions that are right for them.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

March 21, 2018

Written by

Afton + Carly

Fact checked by

Health Guide Team

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