What Causes Infertility
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Disclaimer: This information is for educational purposes only and should not be interpreted as medical advice.
1 in 6 couples experience infertility.
1 in 4 pregnancies end in miscarriage.
If you fall into those numbers, please know you are not alone.
And if you haven’t experienced infertility or miscarriage yourself, someone close to you almost certainly has.Yet many women and couples struggling with infertility or pregnancy loss suffer in silence. It’s a deeply personal experience that often carries grief, confusion, frustration, and sometimes even shame.
Having experienced infertility and miscarriage personally (and having worked with women and couples navigating it), I understand why. Conversations around fertility are often oversimplified or overly medicalized, leaving many people feeling like something is “wrong” with them.
But fertility is far more complex than that. Your body is not broken.
In many cases, infertility is the result of underlying imbalances in the body that can be identified and supported.
Understanding what may be contributing to fertility struggles is often the first step toward restoring it.
What Causes Infertility
Infertility has many potential underlying causes.
Some are structural or genetic. Others are hormonal or metabolic. Many are related to lifestyle or environmental stressors that affect the body’s ability to support reproduction.
In most cases, fertility challenges are not caused by just one issue, but rather a combination of factors.
Some of the most common causes include:
Ovulatory Disorders (Not Ovulating Regularly)
Ovulation is the cornerstone of fertility. Without ovulation, pregnancy cannot occur.
Conditions that can interfere with ovulation include:
Polycystic Ovary Syndrome (PCOS)
Thyroid disorders
Chronic stress
Insulin resistance
Nutrient deficiencies
Hypothalamic dysfunction from excessive stress, exercise, or under-eating
Some women do not ovulate regularly, while others may ovulate but produce eggs that are not optimal in quality.
Ovulation problems account for roughly 25–30% of infertility cases.
Interestingly, some women are ovulating consistently but still struggling to conceive. If that’s you, there are several possible reasons, which I explain in detail in Why You Might Be Ovulating But Not Getting Pregnant.
Low Progesterone
Progesterone is the hormone that stabilizes the uterine lining and supports early pregnancy.
After ovulation, the body should produce adequate progesterone for approximately 10–14 days. If progesterone is too low, or the luteal phase is too short, implantation may not occur or early miscarriage can result.
Low progesterone is more common than many people realize and can be influenced by:
Poor ovulation quality
Chronic stress
Blood sugar imbalances
Thyroid dysfunction
Nutrient deficiencies
Inflammation
We’ll dive deeper into this in a separate blog post on what causes low progesterone.
PCOS (Polycystic Ovary Syndrome)
PCOS is one of the most common hormonal conditions affecting women of reproductive age.
It is often associated with:
Irregular cycles
Lack of ovulation
Elevated androgens
Insulin resistance
But PCOS does not just impact ovulation, it is an endocrine condition that impacts ovarian and hormone function which can impact the whole body.
With the right nutrition, lifestyle support, and metabolic regulation, many women with PCOS can restore ovulation and improve fertility outcomes.
Endometriosis
Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus.
This can cause:
Pelvic inflammation
Painful cycles
Adhesions
Disrupted implantation
Endometriosis affects an estimated 1 in 10 women, and a significant percentage of women with infertility have undiagnosed endometriosis.
How to Know If you have endometriosis:
The only true way to diagnose endometriosis is through laparoscopic surgery. It’s important that you seek out a knowledgeable surgeon for proper treatment. However, there are numerous nutrition and lifestyle supports that can help manage symptoms and improve overall hormonal function.
Thyroid Disorders
Your thyroid gland plays a major role in regulating hormones, metabolism, and reproductive function.
Both hypothyroidism and hyperthyroidism can interfere with fertility by affecting:
Ovulation
Egg quality
Implantation
Progesterone production
Even mild thyroid dysfunction can impact reproductive health, which is why a full thyroid evaluation is often important when investigating fertility concerns.
Male Factor Infertility
Fertility is not just a women’s issue. Male factor infertility contributes to approximately 40–50% of infertility cases.
Common contributors include:
Low sperm count
Poor sperm motility
Abnormal sperm morphology
Hormonal imbalances
Environmental toxin exposure
Poor metabolic health
The good news is that sperm regenerates approximately every 72–90 days, meaning lifestyle and nutritional changes can often improve sperm health within a few months.
Supporting fertility should always involve both partners.
Other Factors Overlooked When It Comes to Infertility
While medical diagnoses like PCOS or thyroid disorders receive attention, many underlying contributors to fertility challenges are often overlooked.
Fertility is not just about the reproductive organs. It is a reflection of whole-body health.
Chronic Stress
Your body is designed to prioritize survival before reproduction.
When the body perceives ongoing stress, (whether physical, emotional, or environmental) reproductive hormones often take a back seat.
Sources of stress can include:
Overwork
Poor sleep
Emotional strain
Excessive exercise
Blood sugar instability
Chronic inflammation
Even though stress alone is rarely the sole cause of infertility, it can significantly influence hormone balance and ovulation quality.
Nutrient Deficiencies
Your body requires an enormous amount of nutrients to support conception and pregnancy.
Key nutrients for fertility include:
Iron
Zinc
Magnesium
Selenium
B vitamins
Vitamin D
Omega-3 fatty acids
Modern diets, soil depletion, digestive issues, and chronic stress can all contribute to nutrient depletion.
If the body does not have the resources it needs to sustain pregnancy, it may delay reproduction until those needs are met.
Digestive Health
Gut health plays a surprisingly important role in fertility.
Your digestive system affects:
Nutrient absorption
Hormone metabolism
Inflammation levels
Immune function
Issues such as:
Gut dysbiosis
Leaky gut
Chronic constipation
Food sensitivities
Can indirectly affect fertility by increasing inflammation and disrupting hormone balance.
Liver Function and Hormone Detoxification
Your liver is responsible for processing and eliminating excess hormones, including estrogen.
When liver detoxification pathways are sluggish (often due to toxin exposure, poor nutrition, or digestive dysfunction) hormones may recirculate instead of being eliminated.
This can contribute to:
Estrogen dominance
PMS
Heavy cycles
Hormonal imbalances that affect fertility
Supporting liver health through nutrition, hydration, and lifestyle can play an important role in restoring hormonal balance.
Environmental Toxin Exposure
Modern life exposes us to a wide range of endocrine-disrupting chemicals.
These can include:
Plastics (BPA, phthalates)
Pesticides
Heavy metals
Personal care product chemicals
Air pollution
These compounds can interfere with hormone signaling, egg quality, and sperm health.
Reducing toxic load where possible can make a meaningful difference over time.
Infertility Is Multifaceted
One of the biggest misconceptions about infertility is the idea that there is always one clear cause.
In reality, fertility challenges are often the result of multiple factors overlapping.
For example, a woman may have:
Mild thyroid dysfunction
Suboptimal progesterone
High stress levels
Nutrient depletion
Poor sleep
Individually, none of these might seem severe. But together, they can significantly impact fertility.
This is why taking a whole-body, root-cause approach is so important.
Instead of chasing one lab value or diagnosis, the goal is to support the body’s overall ability to regulate hormones, ovulate consistently, and sustain pregnancy.
When to See a Medical Provider
Most conventional doctors will recommend waiting one full year of unprotected intercourse before performing a fertility work-up.
For women over 35, that timeline is often shortened to six months.
For recurrent miscarriage, many women are told testing will not occur until after 2-3 pregnancy losses.
For couples experiencing infertility or miscarriage, that waiting period can feel incredibly frustrating.
However, there are other approaches.
Providers trained in Restorative Reproductive Medicine (RRM) or NaPro Technology often take a more investigative approach earlier in the process.
Rather than simply diagnosing infertility, they work to identify and treat underlying hormonal or reproductive issues.
Many of these providers consider infertility after six months of well-timed intercourse.
You Don’t Have to Wait to Support Your Fertility
Regardless of when medical testing begins, there is something important to understand:
You do not have to wait a year to begin supporting your fertility.
In fact, the months before conception are some of the most important months for preparing the body.
Eggs take approximately 90 days to mature before ovulation, and sperm development takes a similar amount of time.
This means the choices you make today (nutritionally, metabolically, and hormonally) influence fertility several months from now.
For this reason, I recommend 3–6 months of preconception support for both partners when possible.
This can include:
Supporting nutrient stores
Stabilizing blood sugar
Improving ovulation quality
Optimizing sperm health
Reducing toxin exposure
Addressing underlying hormonal imbalances
Of course, many couples begin this process after they have already been trying to conceive.
And that’s okay too.
It’s never too late to begin supporting your body.
The Next Steps in Understanding Your Fertility
In upcoming articles, we’ll explore two common — and often misunderstood — fertility challenges:
Why you might be ovulating but still not getting pregnant
and
How low progesterone impacts cycles and fertility.
Both are far more common than many women realize.
Understanding them can provide important insight into what your body may be trying to communicate.
If you are navigating infertility or recurrent miscarriage, please know this:
Your body is not working against you. It may simply need the right support.
And you do not have to walk through that process alone.
If you’re wondering, “How can I increase fertility naturally?”
→ Take the next step by booking your Cycle + Hormone Assessment today
Frequently Asked Questions About Infertility
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Ovulation disorders are one of the most common causes, accounting for roughly 25–30% of infertility cases. Male factor infertility also contributes to nearly half of all cases.
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Yes. Fertility is influenced by many factors including hormone balance, nutrient status, stress levels, and metabolic health. Even small imbalances can affect conception.
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Many conventional doctors recommend trying for one year before testing, but some fertility-focused providers begin evaluating after six months of well-timed intercourse.
It’s never too early to start on nutrition changes. I recommend making changes 3-6 months before trying to conceive.
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In many cases, yes. Nutrition, stress management, toxin reduction, and hormone support can all play a role in improving fertility outcomes.