Table of contents

What is infertility?

Infertility is a condition in which pregnancy does not occur within one year despite regular, unprotected sexual intercourse [1]. For women over the age of 35, this timeframe is reduced to six months, as female fertility naturally declines with age [1]. Infertility affects both sexes: fertility problems occur at nearly the same rate in men and women.

Infertility is affecting an increasing number of couples worldwide. According to WHO estimates, one in six couples – approximately 17.5% of the adult population – now faces fertility challenges. This issue is not confined to any one continent or socioeconomic group: fertility problems occur at similar rates in both high- and low-income countries, highlighting infertility as a genuine global health concern. Since the causes of infertility are often complex and may involve either or both partners, it is essential to examine male and female fertility problems together and in relation to one another. This joint approach helps to better understand the systemic, biological, and environmental factors contributing to infertility, as well as the interactions at the couple level.

The ability to conceive is an extremely delicate biological process involving multiple organ systems. The ovaries must ensure that follicles mature at the appropriate time, after which a hormonal signal from the pituitary gland triggers ovulation—the rupture of the follicle. At the same time, the sperm must be viable and reach the fallopian tube at the right moment for fertilisation. The fertilised egg must then travel to the uterus and successfully implant. Any disruption in these steps—whether hormonal, anatomical, immunological, or cellular—can independently result in infertility.

In about half of all cases, male factors also contribute, such as low sperm count, reduced sperm motility or morphological abnormalities, and genetic issues that prevent fertilisation. Both partners may also have some form of biological barrier, which can sometimes go undetected. It is not uncommon for no clear abnormalities to be found during medical examinations—in such cases, the condition is termed idiopathic infertility, or infertility of unknown origin. [2]

The term ‘subfertility’ is also important to mention. It refers to a state of reduced fertility where conception is difficult and delayed, but not impossible. Subfertility often goes unnoticed, even though timely diagnosis and appropriate treatment could prevent the progression to full infertility. [3]

Infertility is not only a medical issue but also a social and psychological one. Affected couples often bear a heavy emotional burden, while societal pressure, stigma, and delayed diagnosis can worsen the situation. Therefore, open communication and early access to information and appropriate care are crucial.

What are the symptoms and types of infertility?

In many cases, infertility remains hidden, as the main—and often only—symptom is the failure to conceive within the previously mentioned timeframe [4]. However, in some cases, physical signs may indicate underlying issues.

In women, hormonal imbalances are often accompanied by irregular menstrual cycles: cycles that are too short (less than 21 days), too long (more than 35 days), irregular, or entirely absent may suggest ovulation problems [4]. Painful menstruation, pelvic discomfort, or lower back pain may point to endometriosis or other inflammatory gynecological conditions. Additional warning signs may include excessive body hair growth, acne, hair loss, or obesity—particularly in cases of PCOS or thyroid disorders. [1]

In men, the signs of infertility are often less obvious but may include testicular pain, swelling, lumps, or changes in testicle size [5]. Decreased libido, erectile dysfunction, or difficulty ejaculating can also be red flags. Hormonal imbalances may lead to body hair loss or a feminized physique. [6]

However, it is not uncommon for neither partner to exhibit any specific symptoms. In cases of idiopathic infertility, the issue often comes to light only after extended unsuccessful attempts to conceive or during unrelated medical evaluations.

Infertility can be classified according to several criteria [5]:

• Primary infertility: when the individual (male or female) has never achieved a confirmed conception—i.e., the couple has no children and no prior confirmed pregnancy.
• Secondary infertility: when there has been at least one prior confirmed pregnancy–regardless of its outcome (live birth or miscarriage)–but no subsequent pregnancy has occurred.
• Idiopathic infertility: when medical tests reveal no clear or identifiable cause of the fertility problem. [7]

Figure 1. Types of infertility

How is infertility diagnosed? – testing options for women and men

Infertility testing is a complex, multi-step process tailored to each individual’s circumstances, medical history, and symptoms. The goal is to determine at which stage of the reproductive process the problem arises—follicular development, ovulation, sperm motility, fertilisation, or embryo implantation. Since infertility can stem from either partner, both are typically assessed in parallel. [1]

Investigation of female infertility

The functioning of the female reproductive system is influenced by numerous factors, including hormonal balance, ovarian activity, fallopian tube patency, and the condition of the uterus and endometrium—all essential for successful conception. Accordingly, female infertility investigations may involve several tests:

• Medical history and gynaecological examination: The first step includes a detailed medical history, menstrual cycle assessment, and physical examination of both external genitalia and internal reproductive anatomy.
• Hormone tests: Blood samples are analysed for hormone levels (FSH, LH, prolactin, TSH, AMH, estrogen, progesterone) to assess ovarian function, ovulation, and overall endocrine health.
• Thyroid function tests: Thyroid hormones are closely linked to menstrual cycles and ovulation.
• Transvaginal ultrasound: Used to evaluate the structure of the ovaries, uterus, and endometrium; can detect cysts, fibroids, PCOS, or developmental abnormalities.
• Hysterosalpingography (HSG): A contrast-enhanced X-ray to assess the patency of fallopian tubes and identify abnormalities in the shape of the uterine cavity.
• Saline sonohysterogram (SIS): An ultrasound using saline solution for more sensitive detection of uterine cavity abnormalities.
• Hysteroscopy: A procedure that allows direct visual examination of the uterine cavity and, if necessary, targeted surgical intervention.
• Laparoscopy: A minimally invasive surgical method used to directly examine endometriosis, pelvic adhesions, fallopian tubes, and ovaries.
• MRI: Rarely used but valuable in select cases, such as examining the pituitary gland or hypothalamus for hormonal abnormalities. [8]

It’s important to note that not all tests are required for every patient. The diagnostic path is based on the individual’s clinical presentation and medical history.

Investigation of male infertility

Male infertility testing focuses primarily on sperm production, semen quality, and hormonal health. In many cases, a few key assessments provide a comprehensive picture of a man’s fertility status:

• Physical andrological examination: Evaluation of the testicles, epididymis, and penis for structural abnormalities and varicocele (enlarged testicular veins).
• Semen analysis (spermiogram): A microscopic examination of ejaculate to assess sperm count, motility, shape (morphology), sample volume, and pH. Typically performed twice to rule out temporary fluctuations.
• Hormone tests: Blood tests measuring testosterone, LH, FSH, prolactin, and SHBG levels.
• Genetic testing: Recommended in suspected cases of Y chromosome microdeletions, Klinefelter syndrome, or CFTR mutations.
• Scrotal ultrasound: To evaluate testicular volume and detect conditions like varicocele or inflammation.
• Sperm DNA fragmentation test: Assesses the genetic integrity of sperm, especially in cases of miscarriage or repeated failed implantations.
• MRI: Rarely used, but in justified cases, it may be employed to examine the pituitary gland or hypothalamus—for example, to detect hormonal imbalances. [8]

The importance of examining male fertility is often underestimated, even though male factors contribute to about half of all infertility cases. Semen analysis, as a first-line test, is quick, painless, and highly informative.

The role and importance of testing

The goal of infertility diagnostics is not only to identify the underlying causes but also to determine the most effective treatment approach. These tests help guide decisions about whether medication, lifestyle changes, surgery, or assisted reproductive technologies (such as insemination or IVF) are appropriate.

It’s essential to emphasise that diagnostic testing is a process requiring close cooperation between the patient and the medical team. With the availability of modern diagnostic tools, personalised and targeted treatment strategies can be developed, increasing the likelihood of successful outcomes.

What are the risk factors and specific causes of infertility? – from a traditional and functional medicine perspective

A wide variety of factors can contribute to infertility, acting individually or in combination to prevent conception. While conventional medicine focuses on identifying hormonal, anatomical, and infectious causes, functional medicine complements this by examining the fine coordination of the body’s regulatory systems—such as hormonal axes, immune responses, gut microbiome, and cellular energy metabolism.

General risk factors

Certain lifestyle and environmental factors can significantly impair fertility in both men and women:

• Age: Female fertility declines sharply after age 35 due to reduced egg quantity and quality. In men, sperm production slows and the risk of genetic abnormalities increases after age 40.
• Smoking, alcohol, and drugs: Nicotine, ethanol, and cannabinoids negatively affect hormone regulation, reduce sperm count, and raise the risk of miscarriage. [9]
• Body weight: Excess weight increases the risk of insulin resistance, PCOS, and oestrogen dominance; undernutrition may lead to anovulation.
• Environmental toxins: Heavy metals, pesticides, and xenoestrogens damage reproductive cells.
• Sedentary lifestyle or excessive physical activity: Both can disrupt hormones, impair ovulation, and negatively affect testicular function. [1]

Figure 2. General risk factors of infertility.

Female and male infertility – specific classical causes

In many cases, infertility can be traced back to clearly defined, organ-specific abnormalities.

• In women: ovulatory dysfunction (e.g., PCOS, thyroid disorders), fallopian tube obstruction, endometriosis, uterine abnormalities, ovarian insufficiency, or recurrent miscarriage.
• In men: impaired sperm production (e.g., due to testicular damage or genetic abnormalities), varicocele, ductal blockages, hormonal deficiencies, infections, or toxic exposures. [1]

Functional medicine approach – systemic factors

From a functional perspective, infertility is frequently a symptom of broader biological imbalance rather than isolated organ failure. Key systemic contributors include:

Cell-level energy regulation – The role of mitochondria in fertility

Mitochondria are the energy-producing centers of cells, generating ATP (adenosine triphosphate), which powers vital life processes. Reproductive cells—egg and sperm—have exceptionally high mitochondrial activity, as processes like conception, cell division, embryo development, and hormonal balance are all energy-intensive. [10]

Egg cells contain more mitochondria than almost any other cell type in the female body. Mitochondria play a critical role in chromosome separation, cell division accuracy, and epigenetic stability. As maternal age increases, mitochondrial function declines, mitochondrial DNA mutations accumulate, ATP production becomes less efficient, and oxidative stress increases. This leads to reduced egg quality, less frequent ovulation, and implantation issues. [11]

In male gametes, mitochondria are primarily concentrated in the neck region of the sperm, where they play a key role in generating the energy required for tail movement. Mitochondrial dysfunction can reduce sperm motility, increase DNA damage, and impair fertilisation capacity. Sperm DNA fragmentation may not only hinder fertilisation but also contribute to miscarriage, developmental disorders, and embryo loss. [12]

Mitochondria also play a central role in steroid hormone synthesis. The conversion of cholesterol into pregnenolone—the precursor of all steroid hormones (e.g., progesterone, oestrogen, testosterone, cortisol)—takes place on the inner mitochondrial membrane. These hormones influence not only fertility but also immune balance, metabolism, and emotional health. Steroid hormone imbalances can result in reproductive problems as well as fatigue, stress sensitivity, mood disturbances, and increased inflammation. [13]

Furthermore, mitochondria regulate apoptosis, or programmed cell death. This function is essential for healthy tissue renewal, immune system regulation, and proper embryo development. Dysregulated apoptosis can cause the accumulation of damaged cells or excessive loss of healthy ones, impairing conception and pregnancy outcomes. [14]

Mitochondrial function can be impaired by oxidative stress, exposure to environmental toxins (e.g., heavy metals, phthalates, BPA), the presence of inflammatory mediators, and deficiencies in micronutrients such as coenzyme Q10, magnesium, B vitamins (B2, B3, B12), and selenium. Lifestyle factors—like physical inactivity, smoking, sleep deprivation, and highly processed diets—also negatively affect cellular energy metabolism [15].

Functional medicine considers mitochondria central to hormonal and immune regulation. Therapeutic strategies include:

• Antioxidants that support mitochondrial health: coenzyme Q10 (ubiquinone), alpha-lipoic acid, vitamins C and E [16]
• Cofactors for energy production: L-carnitine, B2 and B3 vitamins, magnesium
• Cell-protective agents: selenium, glutathione, NAC (N-acetylcysteine)
• Lifestyle changes: adequate sleep, moderate physical activity, stress reduction, and minimising toxic exposure [17]

Mitochondrial optimisation is especially important in idiopathic infertility, where no specific organic cause is found. A deficiency in cellular energy can impair conception, egg/sperm quality, and embryo development—even when conventional diagnostic tools show normal results.

The role of cell membranes in fertility and mitochondrial function

The cell membrane is not merely a passive boundary—it is a dynamic, regulatory structure that plays a fundamental role in cellular communication, function, and responsiveness. In reproductive cells such as egg and sperm cells, the integrity and fluidity of the cell membrane are essential for successful fertilisation.

The membrane is primarily composed of phospholipids, cholesterol, and proteins. Its composition affects:

• The functionality of hormone receptors (e.g., FSH, LH, oestrogen receptors),
• Cell-to-cell signalling (e.g., embryo-chorion communication),
• Internal metabolic processes. [18]

Membrane fluidity—essentially the flexibility of the membrane—significantly influences how cells respond to hormones, growth factors, and immune signals. Membranes enriched with omega-3 fatty acids (DHA, EPA) enhance the effectiveness of hormone receptors and improve signal transmission. In contrast, trans fats, inflammatory lipids, and toxic byproducts of lipid peroxidation impair membrane function, potentially disrupting reproductive processes. [19]

Proper membrane composition is critical for key reproductive events, including sperm-egg fusion and the acrosome reaction (when the sperm releases enzymes to penetrate the egg’s protective layer). A membrane that is too rigid, damaged, or full of inflammatory lipids may impair the intercellular communication and implantation.

The condition of cell membranes and mitochondrial function are closely interconnected. The membrane structure of mitochondria plays a critical role in energy production (ATP synthesis), cellular metabolism, and the regulation of apoptosis. The stability and integrity of the inner mitochondrial membrane directly affect the efficiency of the electron transport chain, thereby determining cellular energy levels—an essential factor influencing fertility. [12]

Coenzyme Q10 (ubiquinone) plays a dual role in this process: it acts both as a key cofactor in ATP synthesis and as an antioxidant and membrane-protective molecule. Q10 supports the structural integrity of both cellular and mitochondrial membranes, reduces lipid peroxidation caused by oxidative stress, and enhances membrane fluidity—making it a cornerstone of functional fertility support. [20]

Functional membrane support may include:

• Lipid profile analysis (e.g., red blood cell membrane analysis): a growing functional diagnostic tool in fertility care [21]
• Nutritional supplements to enhance membrane elasticity and regeneration: phosphatidylcholine (lecithin), omega-3 fatty acids, vitamin E, inositol, coenzyme Q10
• Anti-inflammatory diet and antioxidant therapy: to prevent lipid peroxidation and preserve membrane integrity [22]

The condition of cell membranes directly affects the fertility potential of reproductive cells. It plays an essential role in hormonal responsiveness, fertilisation, and successful implantation—all of which are closely linked to mitochondrial energy levels and membrane dynamics.

Immunological factors behind infertility

Fertility depends not only on hormonal and anatomical balance but also on proper immune system regulation. Since the embryo carries genetic material from the male partner, the female body must tolerate it as a semi-foreign entity. This biological paradox is managed through finely tuned immune modulation, which must begin before conception. Disruptions in this balance can contribute to infertility, recurrent miscarriage, and implantation failure. [23]

Immunological balance in support of fertility

For a pregnancy to be successful, the immune system must maintain the right balance between Th1 and Th2 immune responses. Th1 dominance promotes inflammation and cell destruction, whereas Th2 dominance encourages tolerance and embryo implantation. In a healthy pregnancy, a shift toward Th2 is observed. If this balance is disrupted—due to autoimmune disease, infection, or chronic stress—conception may be inhibited or miscarriage may occur early in pregnancy [23].

NK cells (Natural Killer cells) and cytotoxic responses

NK cells in the endometrium play a key role in helping the trophoblast (the outer layer of the embryo that facilitates implantation) integrate into the uterine lining. However, when these NK cells become overly active, they may trigger a rejection-like response that prevents implantation or causes early miscarriage. This is often observed in cases of unexplained infertility or repeated IVF failure. [24]

Autoimmune processes

Autoimmune diseases—such as Hashimoto’s thyroiditis, lupus erythematosus, or antiphospholipid syndrome—can produce antibodies against ovarian tissue, the endometrium, or hormonal pathways, leading to infertility or pregnancy complications (e.g., miscarriage, intrauterine growth restriction). [25]

Antiphospholipid antibodies are particularly concerning, as they can cause microclot formation in the blood vessels of the uterine lining, impairing blood flow necessary for implantation.

Both female and male immune systems may also develop antibodies against sperm. These anti-sperm antibodies can:

• Inhibit sperm motility
• Prevent sperm from passing through cervical mucus
• Destroy sperm cells altogether

The immune system and infertility: the supportive role of lipid therapy

Lipid therapy, an intravenous fat-based emulsion, is increasingly used to treat infertility linked to immune dysfunction. In some women, the embryo may trigger an overactive immune response, leading to implantation failure or early miscarriage. Lipid therapy helps suppress this overactivity—particularly that of NK cells—and balances inflammatory responses. It may improve implantation rates and support early pregnancy, especially in cases where other treatments have failed. [26]

The role of hormonal axes, stress and cortisol in fertility regulation

The endocrine system is a highly interconnected network that regulates reproduction through several hormonal pathways. Infertility—particularly of functional origin—is often not due to the abnormal level of a single hormone, but rather to imbalances across multiple axes. The three most relevant axes are:

• HPO axis (hypothalamus–pituitary–ovary): regulates the menstrual cycle, ovulation, and sex hormones
• HPT axis (hypothalamus–pituitary–thyroid): influences cellular metabolism, cycle rhythm, and progesterone sensitivity
• HPA axis (hypothalamus–pituitary–adrenal): governs the body’s stress response and cortisol levels

These neuroendocrine axes are deeply interconnected, meaning dysfunction in one can cascade into others. This section provides a more detailed overview of the functioning and disorders of the HPA axis.

Chronic stress and HPA axis dysfunction

Modern life—marked by constant time pressure, lack of sleep, excessive screen use, uncertainty, and internal tension—keeps the HPA axis chronically activated. This leads to prolonged cortisol production, which directly suppresses reproductive function [27]:

• GnRH inhibition: Cortisol inhibits GnRH (gonadotropin-releasing hormone) release from the hypothalamus, lowering LH and FSH levels, which can lead to anovulation or irregular cycles. [28]
• Cortisol-progesterone competition: Under stress, the body diverts resources to make cortisol from progesterone—a process known as “pregnenolone theft.” This may reduce both the length and quality of the luteal phase, potentially lowering implantation success. [29]
• Thyroid disruption: Chronic stress impairs the conversion of thyroid hormones (T4 to T3), contributing to hypothyroidism and secondary menstrual irregularities. [30]

Inflammation: HPA overactivation increases inflammatory cytokines like IL-6 and TNF-α, which can promote chronic inflammation and disrupt immune tolerance in the endometrium.

Cortisol resistance and deficiency

In the long term, sustained cortisol activity can lead to cortisol resistance, where cells no longer respond effectively to the hormone’s anti-inflammatory effects, resulting in a persistent, survival-oriented inflammatory state. At the same time, the adrenal glands may become exhausted, leading to hypocortisolism, which can cause increased fatigue, irritability, and a complete disruption of the hormonal cycle. [28]

This is often caused by obesity, chronic stress or inflammation, and/or a disrupted circadian rhythm, during which cortisol levels remain persistently high and feedback mechanisms become impaired. In such cases, the body is unable to properly regulate the release of stress hormones, leading to increased tissue inflammation, reduced hormonal sensitivity, and, over time, impaired fertility. [30]

It is particularly noteworthy that the sensitivity and expression of cortisol receptors are established early in life, especially during infancy. Skin-to-skin contact, gentle touch, and nurturing care promote the development of glucocorticoid receptors, which play a key role in the long-term regulation of the stress response. In contrast, inadequate caregiving—such as maternal illness, prolonged incubator stays, or a dysfunctional, trauma-exposed family environment—can lead to lifelong vulnerabilities in steroid hormone regulation. These early influences increase the risk of developing cortisol resistance and hormonal dysregulation later in life, potentially affecting fertility, immune function, and mental well-being. [31]

What is the role of micronutrients in infertility?

A healthy hormonal system and intact anatomical function are not sufficient on their own for reproductive health—the delicate balance of cellular metabolism and regulatory processes is at least equally important. Micronutrients—including vitamins, minerals, and trace elements—play a key role in maintaining this balance. Their deficiency often does not cause specific symptoms, yet it can significantly impact conception rates, egg and sperm quality, as well as the success of implantation and pregnancy maintenance.

Folate (5-MTHF) – cornerstone of methylation and fetal development

Folate (naturally occuring vitamin B9) is critical for DNA synthesis, cell division, and the methylation cycle [43]. Adequate levels before and during conception lower the risk of neural tube defects, miscarriage, and implantation issues. Importantly, some individuals carry an MTHFR gene polymorphism, which reduces the body’s ability to convert synthetic folic acid into its active form. These individuals benefit from 5-MTHF (biologically active methylfolate) supplementation, which directly supports cellular function and embryonic development. [44]

Vitamin B12 – DNA protection and luteal phase support

Vitamin B12 (cobalamin) is an essential cofactor in cell division, homocysteine metabolism, blood formation, gene expression, and protein synthesis via DNA synthesis. It also supports detoxification processes through its role in methylation pathways. In women, B12 deficiency is associated with luteal phase deficiency—a disruption of the second half of the menstrual cycle, when progesterone prepares the uterine lining for implantation—as well as implantation disorders and an increased risk of miscarriage. In men, it can lead to reduced sperm count, poor motility, and DNA damage. Vegetarians, vegans, and individuals with malabsorption issues (e.g., inflammatory bowel disease, or use of proton pump inhibitors) should pay particular attention to supplementation, ideally in the form of methylcobalamin or hydroxycobalamin. [43]

Vitamin D – hormonal regulation and immune defence

Vitamin D acts like a steroid hormone, influencing oestrogen-progesterone balance, ovulation, endometrial health, and immune adaptation during pregnancy. Deficiency is common in women with PCOS, endometriosis, or recurrent miscarriage. In men, vitamin D supports testosterone production and sperm motility. Vitamin D receptors are found in the ovaries, uterus, testicles, and placenta—highlighting its wide-reaching influence on reproductive health. [45]

Vitamin A: mucosal protection, immune tolerance and hormonal regulation in the service of fertility

Vitamin A (retinol and its active derivatives, such as retinoic acid) supports fertility and reproductive health on multiple levels. It is essential for maintaining the integrity of mucous membranes, including those of the endometrium and cervical mucus, both of which are critical for implantation and sperm motility. [46]

Vitamin A also plays a vital role in immune system regulation, particularly in fostering mucosal immune tolerance. It promotes the differentiation of T-regulatory cells, which help reduce autoimmune activity—an important factor in cases of immunologically driven infertility.

In addition, vitamin A is closely linked to vitamin D. As a cofactor, it helps activate vitamin D receptors (VDR), thereby enhancing vitamin D’s hormonal and immunomodulatory effects.

Moreover, vitamin A contributes to the regulation of steroid hormones, including the biosynthesis of testosterone—a key factor in male fertility and sperm production. [47]

Magnesium – stress management and hormonal balance

Magnesium is a cofactor in over 300 enzyme systems, including those responsible for sex hormone production and cellular stress response. It supports progesterone balance, eases menstrual cramps, and improves blood flow to the uterine lining. Stress, caffeine, alcohol, and processed foods deplete magnesium levels. Elevated cortisol, often seen in fertility challenges, further increases the need for magnesium. [48]

Zinc – protector of reproductive cells

Zinc is essential for spermatogenesis, ovulation, and cell division. It supports testosterone and progesterone production and provides antioxidant protection for reproductive DNA. Deficiency is associated with reduced fertility and a higher risk of miscarriage. Because zinc levels fluctuate during the menstrual cycle—and thus affect sensitivity to LH and FSH—consistent intake is important throughout all phases. [49]

Selenium – antioxidant and thyroid-supportive micronutrient

Selenium reduces oxidative stress through the action of glutathione peroxidase, supports thyroid hormone production, and protects the integrity of reproductive cells. In women, it may enhance endometrial receptivity, while in men, it can improve sperm motility and vitality. Monitoring selenium status is particularly important in cases of autoimmune thyroid disease. [50]

Iodine – the thyroid–reproduction connection

Even mild iodine deficiency can negatively impact fertility. Iodine is essential for the production of thyroid hormones (T3 and T4), which regulate metabolism, the menstrual cycle, ovulation, and implantation. As these hormonal processes are fundamental to female reproductive function, even a slight deficiency can contribute to luteal phase defects, implantation failure, or recurrent miscarriage. [51]

While the connection between iodine and infertility has been recognised for some time, recent research has shown that iodine’s effects extend beyond thyroid hormone regulation. Glandular tissues—such as those in the breasts, ovaries, and thyroid—store significant amounts of iodine, partly because they are highly susceptible to bacterial and viral infections. Iodine supports these tissues by acting as a natural antimicrobial agent.

Additionally, iodine plays a role in regulating body temperature via the thyroid. A deficiency can lead to lower body temperature, weakening the immune system and increasing susceptibility to infections and inflammatory conditions. Over time, this may contribute to the development of chronic illnesses—often referred to as “long-term patient journey”—with infertility being a common and frequently overlooked manifestation. [52]

Since iodine deficiency is widespread globally, due in part to low iodine content in soil and drinking water, supplementation (e.g., iodised salt or targeted nutritional products) may be a key strategy in the prevention or complementary treatment of infertility.

Omega-3 Fatty Acids – Hormonal Balance and Inflammation Reduction

EPA and DHA promote ovulation, enhance endometrial receptivity, and reduce inflammation. In men, they improve sperm motility, morphology, and DNA integrity [53]. Because the typical Western diet is rich in omega-6 fats, a proper omega-3 balance is essential for counteracting inflammatory excess.

What are the treatment options for infertility? – integrating conventional and functional medicine

Today, infertility can be addressed using a wide range of tools, reflecting the complexity and diversity of its underlying causes. The goal is not only to enable conception but also to support a healthy, full-term pregnancy. Increasingly, successful outcomes are being achieved through a combination of conventional and functional medical approaches.

Conventional medical treatments

Conventional medicine typically focuses on pharmacological stimulation, surgical interventions, and assisted reproductive technologies (ART) to treat infertility. These methods offer effective, targeted solutions when clear hormonal, anatomical, or mechanical issues are present.

Common treatments include:

• Ovulation induction (e.g., clomiphene citrate, letrozole): used in cases of anovulation
• Hormone replacement (e.g., thyroid hormone, progesterone): for endocrine imbalances
• Surgical procedures: to treat endometriosis, fibroids, fallopian tube blockages, or varicocele
• Insemination (IUI) or in vitro fertilisation (IVF, ICSI): recommended when spontaneous conception is unsuccessful after multiple attempts, or when genetic or functional issues are diagnosed. [54]

These techniques are invaluable but may not always resolve the issue—particularly in cases of idiopathic infertility, where no clear cause can be identified through standard testing.

Functional medicine-based approach

Functional medicine seeks to uncover systemic imbalances that contribute to infertility. These often involve hormone regulation, gut microbiome health, immune function, or cellular energy metabolism.

Core areas of support include:

• Balancing hormonal axes (HPO, HPT, HPA): by optimising cortisol, thyroid hormones, and sex hormones
• Gut microbiome regulation: using stool analysis, personalised probiotics and prebiotics, and dietary/lifestyle changes
• Mitochondrial support: via coenzyme Q10, magnesium, B vitamins, selenium, and antioxidants
• Mitochondrial and cell membrane balance, and inflammation reduction: the role of omega-3 fatty acids, phosphatidylcholine, and inositol
• Targeted supplementation of micronutrient deficiencies—including folate (5-MTHF), B12, vitamin D, zinc, selenium, iodine, and iron—based on individual laboratory testing.
• Stress management and nervous system regulation: stabilization of the HPA axis with adaptogens, improved sleep, and relaxation techniques. [55]

This holistic approach is especially effective in complex cases such as idiopathic infertility, recurrent miscarriage, PCOS, endometriosis, luteal phase defects, or male factor infertility.

Figure 3. Treatment options for infertility – conventional and functional approach.

An integrated approach – the way forward

The most promising therapeutic results often come from combining conventional medicine with functional and lifestyle-based interventions. Nutrition, micronutrient therapy, stress reduction, and microbiome optimisation not only improve the chances of conception but also promote fetal development and reduce the risk of pregnancy complications.

Summary

Infertility is a growing and often hidden challenge that places a heavy physical and emotional burden on couples. While conventional medicine is essential for diagnosis and intervention, it may fall short in identifying or addressing the root causes—especially when standard tests reveal no abnormalities or treatments are unsuccessful.

Functional medicine, on the other hand, focuses on root causes and examines the balance of the body’s regulatory systems—such as hormonal axes, the gut microbiome, immune response, and cellular metabolism—while supporting their optimal function. It identifies key factors like micronutrient deficiencies, stress-induced cortisol imbalances, intestinal dysbiosis, mitochondrial dysfunction, and reduced cell membrane elasticity, all of which can impair fertility.

The examination of the gut microbiome is a particularly important tool in the functional approach to infertility, as gut microbiome directly influences hormone balance, immune defense, inflammatory processes, and even the condition of the vaginal and testicular microbiota.

At HealWays, we help uncover the systemic imbalances underlying fertility challenges. To do this, we use modern, science-based functional diagnostic tools—such as microbiome testing, hormone profiling, and nutrient status assessment—to provide personalised guidance. Based on the results, we develop a targeted, individualised treatment plan that may include dietary and lifestyle recommendations, stress management strategies, and tailored micronutrient and probiotic supplementation.

Our aim is not just to treat symptoms, but to restore the body’s natural balance—supporting both conception and a healthy pregnancy.

References

[1] ‘Infertility: Causes & Treatment’, Cleveland Clinic https://my.clevelandclinic.org/health/diseases/16083-infertility

[2] ‘Infertility’, Nov. 19, 2019 https://www.hopkinsmedicine.org/health/conditions-and-diseases/infertility

[3] ‘Infertility’, WikipediaMay 30, 2025, https://en.wikipedia.org/w/index.php?title=Infertility&oldid=1293128266

[4] ‘Female infertility-Female infertility – Symptoms & causes’, Mayo Clinic https://www.mayoclinic.org/diseases-conditions/female-infertility/symptoms-causes/syc-20354308

[5] ‘Infertility – Types, Causes, Symptoms, Treatment and Prevention’, Jan. 22, 2025 https://www.pacehospital.com/infertility-types-causes-symptoms-treatment-prevention

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