Polycystic ovary syndrome (PCOS) is one of the most common causes of infertility and affects 6-12% of people in the U.S. who menstruate. Between 50-75% of people with PCOS experience infertility.
However, having PCOS doesn’t necessarily mean you can’t get pregnant. Infertility in PCOS patients isn’t due to a structural or irreversible issue but rather the prevention or delay of ovulation due to particular hormonal imbalances.
Although PCOS has no cure, many women find that addressing those imbalances through diet, lifestyle, or even medication can help to restore fertility. Read on to learn how PCOS influences reproduction and what you can do to improve your chances of conception and healthy pregnancy.
How does PCOS affect fertility?
PCOS is a hormonal disorder, and having too many “male” hormones—called androgens—is a hallmark feature. Excess androgens can interfere with the hormonal interactions necessary for the ovaries to release an egg. Once you restore ovulation, the body can become capable of pregnancy again.
In a healthy menstrual cycle, various hormones interact with each other in a specific order that allows egg cells, or oocytes, to grow inside follicles in the ovary. Here is how this works:
- First, the hypothalamus produces gonadotropin-releasing hormone (GnRH). GnRH catalyzes the release of two other hormones in the pituitary gland: follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
- FSH stimulates the growth of follicles in the ovary that contain immature eggs and the conversion of androgens into estrogen.
- Estrogen increases as one follicle becomes dominant (the reason is somewhat random). An egg matures inside the dominant follicle while the other follicles disintegrate.
- Estrogen then signals the pituitary gland to release LH. LH causes the egg to burst from the follicle in the ovary and travel down the fallopian tube to the uterus, where the sperm can fertilize it. This release of the egg is called ovulation. Without ovulation, pregnancy can’t occur.
People with PCOS often have excess androgen levels, known as hyperandrogenism (too many “male” hormones, like testosterone). Hyperandrogenism throws off the balance of hormones, which can prevent the delicate hormonal process required for an egg to develop, mature, and be released.
In people with PCOS, excess androgens contribute to an increased rate of GnRH secretion, which leads the body to produce more LH and less FSH than normal. Without enough FSH, follicle growth can’t happen. Meanwhile, when there is too much LH compared to FSH, it also halts the process of converting androgens into estrogen. Without enough estrogen, an egg can’t develop or mature. Additionally, the lack of estrogen prevents the surge in LH responsible for the egg ultimately breaking out of the follicle.
In sum, this hormonal domino effect can muddle the entire messenger system required to create and release a healthy egg. Instead, the dysregulation of these hormones can result in the formation of fluid-filled cysts on the ovaries, for which the condition is named.
People with PCOS have symptoms like long cycles, missing periods, or polycystic ovaries because they are not ovulating. When someone isn’t able to get pregnant because they aren’t ovulating, it is called anovulatory infertility. PCOS patients make up 80% of all people affected by anovulatory infertility.
How insulin resistance impacts ovulation
As discussed, PCOS directly impacts reproductive health, and the underpinnings of that impact are closely linked to metabolic health. Insulin resistance, in particular, can have implications for fertility and pregnancy by disturbing the hormonal process required for ovulation.
Here is a quick refresher on insulin resistance:
- Our body uses insulin, a metabolic hormone, to stabilize blood sugar levels.
- When blood sugar levels go up, we produce more insulin to help shuttle it into cells.
- When we make too much insulin (because we have too much blood sugar), our cells can become “numb” to insulin’s effects, a state called insulin resistance.
- When our body enters an insulin-resistant state, it produces even more insulin to compensate, further exacerbating the problem until it can no longer keep up and blood sugar levels remain chronically high, which can eventually lead to prediabetes or Type 2 diabetes.
Excess insulin interferes with how hormones are released from the brain, liver, and ovaries, ultimately leading the body to produce more androgens.
- Brain: If insulin is too high, it can trigger the brain to release GnRH faster, which sets the chain of events in motion that increases androgen production and prevents eggs from developing correctly, as explained above.
- Liver: Extra insulin can also impair the liver’s ability to release a protein called sex hormone binding globulin (SHBG), which helps to control how the body uses androgens. As the name suggests, SHBG binds to testosterone, and with less SHBG, more testosterone circulates in the blood.
- Ovaries: Insulin can directly stimulate theca cells in the ovary to make more androgens.
Insulin resistance is so central to PCOS that in 2012, the NIH even recommended that we call PCOS a metabolic disease. While insulin resistance isn’t always the cause of PCOS, it contributes to 50-90% of all cases. Understanding and managing insulin resistance is a critical strategy for many PCOS patients to regain fertility and have a successful pregnancy.
PCOS and pregnancy
Research suggests that PCOS not only can cause infertility but also can increase the risk of pregnancy complications.
One review of 40 studies that includes data from 141,572 pregnancies found that PCOS is associated with a higher risk of gestational diabetes, preeclampsia, high blood pressure, miscarriage, and preterm birth.
During pregnancy, the body naturally goes into a state of insulin resistance to ensure enough glucose for the fetus. Research suggests that when this increase in insulin resistance from pregnancy combines with preexisting insulin resistance from PCOS, it leads to a higher risk of these metabolically-influenced pregnancy complications.
A pregnant woman with PCOS might not be able to produce enough insulin to adequately process blood sugar, causing blood sugar to remain high and increasing the risk of gestational diabetes. In one study of 72 pregnant people with PCOS, those who developed gestational diabetes came into pregnancy with higher insulin resistance than those who didn’t develop gestational diabetes.
Excess insulin can cause high blood pressure, which increases the risk of both preeclampsia and low birth weight. High androgen levels are also associated with complications like preeclampsia, miscarriage, and preterm birth. One theory is that excess androgens can impair the function of the placenta, which transports blood and nutrients between parent and fetus.
We need more research to understand how PCOS relates to pregnancy complications, specifically how androgens are involved. For example, we know that people with preeclampsia tend to have up 1.5 – 2.4 times the normal amount of testosterone, but we don’t know if or how this hormone plays a causal role. Further insights into the hormonal mechanisms behind these heightened risks can enable better clinical care.
How can I improve my chances of conceiving if I have PCOS?
Even if you’ve been diagnosed with PCOS, conception is possible when you rebalance your hormones to regain the ability to ovulate.
Most treatment options for PCOS aim to reduce androgen or insulin levels so that the hormones needed for a healthy menstrual cycle can resume normal function. If you think you have PCOS, the first step is to determine if you have high androgens, high insulin, or both.
A clinician can check for androgen irregularities through blood work or by assessing androgenic symptoms. Your doctor can measure your metabolic health by checking your levels of insulin and glucose through blood work as well, which can help shed some light on if—and to what degree—insulin may play a role.
It also may help to check cortisol levels to see if the adrenal system—two glands above the kidneys—is being taxed from too much stress. Similar to the role of insulin, cortisol can also contribute to increasing androgens (more on this below).
Lifestyle changes to improve PCOS and restore ovulation
Improving insulin resistance for those with high androgen or insulin levels can help restore a healthy cycle and decrease PCOS symptoms. If insulin resistance isn’t a part of your PCOS journey, but high cortisol is, focusing on lowering stress would be most beneficial.
If none of these hormones are out of range, you may want to work with a clinician to investigate further what may be causing your PCOS symptoms. Confirming that infertility is coming from PCOS rather than a separate issue is essential.
There is extensive evidence that eating to maintain stable blood sugar levels can significantly lower insulin resistance. Foods with a low glycemic index release energy slowly, gradually affecting blood sugar rather than resulting in a spike. Reducing glucose spikes can help reverse insulin resistance.
Based on the mechanisms by which insulin impacts the menstrual cycle, decreasing insulin resistance should help to restore a healthy cycle. Unfortunately, research specifically tying a low-GI diet to fertility outcomes is limited. One older study of 17,544 women who didn’t have PCOS found that those following a low-GI diet had a 66% reduced risk of infertility due to ovulatory disorders. In 2010, another study found that a low-GI diet improved pregnancy outcomes in 46 overweight women, including preterm delivery. But, whether or not they had PCOS was not part of this study.
An analysis of studies that looked at 412 overweight people with PCOS found that a low-GI diet lowered testosterone levels and improved fertility. The authors recommend weight loss via diet change as a fertility treatment. However, the study doesn’t offer specific insights into how fertility improved, such as how many participants successfully became pregnant.
For overweight people, there is strong scientific support for weight loss as a strategy to reverse PCOS. When it comes to fertility, studies have shown that weight loss can help regulate the menstrual cycle, restore ovulation, and even improve the chances of pregnancy. This is likely because reduced insulin resistance from weight loss can lower androgens.
In one study, 60 of 67 subjects started ovulating again after losing about 10 kg (22 pounds). Fifty-two participants went on to get pregnant, and 45 successfully had a child. The miscarriage rate was 18% compared to 75% before the program.
Research suggests that losing 5% of your body weight may help with PCOS symptoms. Fat tissue influences how well our body can respond to insulin, thus lowering body fat can improve insulin resistance.
A caveat here is for those with PCOS who are not overweight. Evidence demonstrates that these people often still have poor glucose and insulin responses compared to healthy peers of the same weight. Focusing on strategies targeting glucose and insulin sensitivity would likely be more effective for this subgroup, as would further investigating whether there is an adrenal component (discussed below!).
Regularly working out can help improve how the body utilizes glucose, which can lower insulin resistance in people with PCOS.
One review of 33 articles found that high-intensity (HIIT) exercise caused the most significant reduction in body weight and insulin resistance in people with PCOS, compared to other forms of exercise. However, moderate-intensity workouts also carried a measurable benefit. Another study looked at the effects of a six-month diet and exercise program on ovulation for people with PCOS. Nine of the 18 participants started ovulating regularly again following the program, and the mean weight loss was 2-5% of their body weight.
But be careful here, as too much HIIT can worsen PCOS in some people, particularly those who are not overweight. When we exercise at a high intensity, our cortisol levels increase, which can cause the adrenal glands to release more androgens.
The adrenal glands can contribute to hyperandrogenism in PCOS. Research suggests that PCOS patients with a lower BMI are significantly more likely to have adrenal androgen excess. So, if people in this camp hit it too hard at the gym, extra cortisol can lead to greater androgen production, exacerbating PCOS and increasing fertility and pregnancy risks rather than decreasing them. This is why HIIT is more likely to be helpful for those with more body weight to lose.
However, evidence shows that resistance (strength) training can help improve glucose absorption, lower insulin resistance, and lower body fat. Our muscles are significant energy consumers, taking up around 70-80% of glucose from the blood.
In one study of 12 overweight women with PCOS, a combination of three sessions of resistance training per week for 12 weeks, alongside nutritional advice, significantly reduced body fat, waist circumference, and insulin levels. Those who just got nutritional advice didn’t lose as much weight but saw similar benefits to their waist and insulin levels.
While research is yet to determine which type of exercise is best for PCOS, simply moving more often can help improve glucose tolerance, improving insulin levels. For example, walking after a meal can stabilize your blood sugar. Focusing on strength training without pushing yourself too hard is also an excellent place to start.
There are also a few medical options to consider. One is metformin, often used to treat Type 2 diabetes. It improves how our body can absorb glucose from the blood and lowers insulin levels. It can also reduce insulin resistance in PCOS, which helps stabilize androgen levels and restore a healthy menstrual cycle so ovulation can occur.
Metformin is generally considered effective. In one review of seven studies involving a total of 702 women, those who took metformin were more than twice as likely to get pregnant than those who didn’t take anything. There’s a caveat: not only can metformin come with side effects like nausea and diarrhea, but because recent studies have shown conflicting results, some researchers have called for more evidence on how it should be prescribed. Check with your doctor if you’re considering using metformin.
There’s also clomiphene, which can instigate the surge in LH that brings on ovulation. It can be helpful for some people but doesn’t have an effect on up to 40% of people with PCOS. Treatment is done in five-day cycles, after which the dose increases until either ovulation occurs or you reach the maximum strength (150mg). Doctors generally recommend around 3-6 cycles, and the conception rate per cycle is 22%.
Cortisol gets a bad rap as the “stress hormone.” Yet we need it to regulate essential bodily functions, like our immune system. Cortisol is part of our body’s response to stress. The brain releases adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce cortisol and androgens.
Cortisol stimulates the liver to produce more glucose, making more energy available for the body. However, the cortisol is “used up” in the process, and to replenish its levels, more ACTH is released, which triggers the production of more androgens.
For people with PCOS, reducing stress can lower both androgen and insulin levels and improve symptoms like fertility. In one study of 84 women with PCOS, a 16-week regimen of low-frequency electroacupuncture (when the needles have a mild electric current) lowered their testosterone levels by 25% and helped to restore their menstrual cycles.
Other treatments for lowering stress and anxiety, including talk therapy and mindfulness, have also been shown to improve the chances of pregnancy. However, we need more research to understand the mechanisms at play better here and how these therapies can specifically help people with PCOS. That said, there isn’t a downside to feeling less stressed. It’s great for your health and doesn’t have side effects, so it’s worth trying strategies like mindfulness or relaxation.
If you have PCOS and want to make changes to support your fertility, making healthy metabolic choices may help. Improving your metabolic fitness can only improve your PCOS and long-term health.