Factors That Affect Fertility For Men And Women

January 29, 2023 29 mins to read

So you are thinking about conceiving or maybe you have been struggling to conceive and are searching for some answers. Either way this article, will help you to lay down the most fertile nutritional soil possible to ensure a healthy pregnancy. There are tons of books, magazines, articles and social media posts from numerous experts (and unqualified individuals) giving all sorts of advice on what can and cant affect fertility, so it can get pretty confusing and it’s easy to get overwhelmed. This advice isn’t meant to replace your physician, oncologist or nutritionist, but is a document that can give you some possible causes, if you are struggling to conceive and some ways to improve your fertility and chances of conceiving.

It’s important to point out that in these lists even if you have one or more factors it doesn’t necessarily mean you won’t be able to conceive, all it means is that your fertility may be less than optimal. Also body fat plays a vital role in pregnancy because estrogen, which is essential for pregnancy is partly stored in body fat (adipose tissue). Therefore you’ll see allot of points around keeping a healthy weight and ensuring a healthy diet with adequate nutrition. Below are factors which have been studied and proven to be related to altered fertility in both women and men along with ways to improve fertility in each area.

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Factors that affect fertility: Men and Women

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Factors that affect fertility: Women

Below are the factors that affect fertility in women specifically (men excluded – see next section below). I put this in an accordion to make the info look less intimidating; left click any of the titles/headers or the arrows to expand each section you want to read.

This one is pretty obvious, but it may take a few weeks to several months for a woman’s fertility to return to normal after stopping use of contraceptives. This shouldn’t be used to assume pregnancy isn’t possible immediately after stopping contraceptives, as they do not provide immediate protection against pregnancy.

Generally just give it time after stopping contraceptives, and if you aren’t conceiving shortly after it might simply not have been long enough. Contact your physician if it has been several months of trying to conceive after stopping contraceptive use.

  1. Anorexia Nervosa is characterized by restrictive eating and excessive weight loss.
    • Can disrupt hormonal balance required for ovulation and menstruation.
    • Even If ovulation does occur, associated low body weight and nutrient deficiencies can negatively impact the quality of eggs and increase risk of miscarriage.
  2. Bulimia nervosa is characterized by binge eating followed by purging/vomiting.
    • Can also disrupt menstrual cycle and lead to amenorrhea (absence of menstrual periods).
    • Frequently vomiting long-term can damage reproductive organs and make it difficult for a woman to conceive.

My advice is if you have either of these health conditions to book an appointment with a psychiatrist, psychologist or eating disorder specialist who can work with you on your condition.

A vegan diet lacks: adequate nutrition, complete proteins (that have all 9 essential amino acids), and omega 3 essential fatty acids, both of which are found primarily in meat, dairy or fish products.

My advice is if you are fixed on a vegan diet while conceiving, hire a nutritionist with experience in a vegan diet (which I have) who can work closely with you to to ensure your daily meals meet adequate nutritional intake. Also have a doctor keep an eye on your blood work to seek out any deficiencies or potential issues which may arise (more info below).

  1. Nutrient deficiencies: such as iron, zinc, vitamin B12 and omega-3 fatty acids which are vital to fertility and deficiency can cause irregular menstrual cycles, and make it more difficult to conceive.
  2. Low calorie intake: it’s easy for someone consuming meat and dairy to load up on calories, but not so much for vegans because generally veggies have lower amounts of calories. When you consume more calories than you burn the excess energy is stored as fat, which if not to excessive is actually good for pregnancy.
  3. Lack of complete proteins: There are two classes of proteins: complete and incomplete. There are exceptions, but generally most animal products are complete proteins while plant products are incomplete proteins. For a vegan to get all the essential amino acids ( that their body can’t produce), they have to compliment proteins (mix and match foods). These can also be less bioavailable or less is absorbed, where they can be used by the body.
  4. Low body weight: this isn’t always true as vegans come in all shapes and sizes. But often due to lack of calories and quality proteins, vegans often lose fay and lower body weight. Low body fat plays a role in estrogen production, and being underweight can disrupt hormonal balance and ovulation.
  5. Hormonal Imbalances: As stated in the above point #4 vegan diets can disrupt hormonal balance especially estrogen and progesterone.

I want to mention I was a vegan for 10+ years until my health degraded as a result (also pescatarian, vegetarian, vegan) and have tried every diet under the sun including: keto, low fodmap, elimination diet, high fat diet, meat only diet, etc). I have allot of compassion for animal welfare and encourage people to purchase grass fed, free range and/or from small local farmers or hunt wild game, because I’m strongly against factory farming. Heck I cry when I see a pig squealing for help!

I know how devout vegans are (I argue with them on social media all the time) and I get it. I really do. The issue is I get allot of attitude from vegans who think “I can do veganism better than all the vegans before me because I know better!!!”. Please understand that when trying to conceive and grow a fetus, a vegan diet is extremely dangerous, and I strongly caution against it. Even if you do conceive, there’s a strong chance your infant may not have reached it’s developmental potential, due to simply having lower levels of building blocks essential for growth and brain development.

If however you still insist on a vegan diet, and aren’t absolutely furious at me yet, hire me or another nutritionist with experience in vegan diets as well book a physician, who can carefully plan your meals and diet to make sure your growing baby has all the essential nutrition it needs, to reach it’s fullest potential and that there are no complications.

If you aren’t already aware, women have a set number of eggs (unlike men who keep producing millions of sperm daily), and as they age the number and quality of their eggs decrease which lowers fertility and makes it difficult to conceive and raises risk of miscarriage.

The eggs in her ovaries become less likely to fertilize and consequently result in a healthy pregnancy. Also older eggs have a higher risk of chromosomal abnormalities which means higher risk of miscarriage or genetic disorders. There’s also hormonal imbalances to worry about and other health conditions which can affect a woman’s ability to conceive.

Menopause doesn’t occur until around age 45-55 (but sometimes earlier). So yes you can still become pregnant after age 35, it just comes with an increased risk of genetic disorders, miscarriage and other complications.

Again I recommend hiring an experienced nutritionist and doctor or naturopath if you are over 35, where blood tests can be done, hormonal levels checked, and diet / supplementation to be custom tailored to resolve any deficiencies or imbalances.

This encompasses a group of risk factors which increase risk of heart disease, diabetes and stroke including: abdominal obesity (waist fat), high blood pressure (130+ systolic – 85+ diastolic), high blood sugar (fasting 100+ mg/dL), high triglycerides (150+ mg/dL) or low levels of good cholesterol (HDL <40 mg/dL for men & 50 mg/dL for women) it can affect a woman’s fertility and ability to conceive in multiple ways.

  • Hormonal imbalances: Metabolic syndrome can disrupt hormones that are important for ovulation, such as insulin and estrogen.
  • Polycystic ovary syndrome (PCOS): Women with metabolic syndrome often have PCOS, which can cause infrequent or irregular ovulation, making it difficult to predict when a woman will ovulate and become pregnant.
  • Insulin resistance: Metabolic syndrome can cause insulin resistance which can make it difficult to ovulate.
  • Higher risk of miscarriage: If you haven’t already got the idea that metabolic syndrome in it’s many forms increases risk of miscarriage due to associated underlying health issues.

PID is an infection in female reproductive organs usually caused by bacteria such as chlamydia, gonorrhea or any others that ascend from the vagina and cervix to uterus, fallopian tubes and ovaries. This condition can affect a woman’s ability to conceive in several ways:

  1. Infertility: PID can cause scarring in the fallopian tubes, which can block the tubes and make it difficult for an egg to travel to the uterus.
  2. Ectopic pregnancy: Damaged fallopian tubes means the egg may fertilize in the tube instead of the uterus where it should. Not only are these types of pregnancies not possible, but can be life threatening to a woman.
  3. Chronic Pelvic Pain: can make intercourse uncomfortable or painful, which may lead to reduced sexual activity and therefore success conceiving.
  4. Adhesions: PID caused inflammation can cause adhesions (bands of scar tissue) in pelvic area, which can lead to infertility due to chronic pelvic pain and ectopic pregnancy.

PID often goes undiagnosed as it has virtually no signs or symptoms. Therefore if she does suspect she has PID she should seek a physician immediately. As mentioned above Sexually Transmitted Infections can increase risk of PID, so for those sexually active practicing safe sex and getting regular tests are key to avoiding PID and a variety of other issues that may make it difficult to conceive.

Endometriosis is a condition where the tissue that normally lines the inside of the uterus grows outside of it, which can affect a woman’s fertility by causing pelvic pain, irregular periods, and infertility. Consult your physician for help with this condition.

Polycystic ovary syndrome (PCOS) is a hormonal disorder that can cause irregular periods, high levels of male hormones, and the growth of small cysts on the ovaries, which can affect a woman’s fertility by causing difficulty ovulating and an increased risk of miscarriage.

Low iron stores (aka iron deficiency anemia) plays a key role in production of hormones responsible for ovulation, which can cause irregular menstrual cycles and infertility. Also iron is responsible for RBC and carrying oxygen in the blood. Low oxygen levels due to iron deficiency can damage ovaries and uterus, further diminishing fertility.

Generally women are more at risk of iron deficiency due to loss of blood during menstruation. In addition women on a vegan or vegetarian diet are even more at risk because meat often has higher levels of iron and is more bioavailable (more easily absorbed), than plant based sources of iron.

Diet is the cornerstone of a healthy pregnancy. A high-fiber diet can positively impact fertility in the following ways:

  • Promotes healthy hormonal balance
  • Regulating blood-sugar levels which can reduce insulin resistance (factor in PCOS and irregular ovulation)
  • Promotes regular bowel movements which can lead to inflammation reductions throughout the body (benefits those with endometriosis)
  • Promotes weight-loss and helps maintain a healthy weight which can improve ovulation and increase fertility
  • Helps detox the body of toxins which helps the body in a variety of ways by reducing oxidative damage and inflammation

Adding fiber into your diet is fairly easy, regardless of diet type, and can benefit women trying to conceive in many ways, making it an easy way to increase fertility and chances of conceiving.

This also goes by the name amenorrhea (period) or anovulation (ovulation), and affects fertility by preventing release of egg from ovary and formation of uterus receptive and able to fertilize the egg. It goes without saying that No ovulation = no egg available to be fertilized by sperm, which makes pregnancy impossible.

Not having a period or having irregular periods can also be a warning sign of hormonal imbalances and underlying health conditions such as PCOS, thyroid or eating disorders and other such conditions which can all cause infertility and difficulty conceiving. Lack of period can also cause high levels of male hormones like testosterone and growth of small cysts on the ovaries.

If your period is irregular you should consult a doctor immediately, as catching issues early can increase chances of a positive health outcome and improve fertility if trying to conceive.

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Factors that affect fertility: Men

Below are the factors that affect fertility in men specifically (women excluded – see next section below). I put this in an accordion to make the info look less intimidating; left click any of the titles/headers or the arrows to expand each section you want to read.

Inadequate zinc intake can affect male fertility by decreasing testosterone levels and sperm quality, resulting in poor sperm motility and low sperm count.

The recommended daily intake of zinc is:

  • Men 7-9 mg per day for men
  • Women 7-8 mg per day for women
  • Pregnant and breastfeeding women 11-12 mg per day

You can increase zinc intake by consuming more zinc rich foods or taking a supplement. Just be aware that excessive zinc intake can also have negative health effects. Here are some zinc rich foods:

  • Oysters (74 mg per 100 g)
  • Beef or lamb liver (5-6 mg per 100 g)
  • Pumpkin seeds (5 mg per 100 g)
  • Cashews (4 mg per 100 g)
  • Chicken (3 mg per 100 g)
  • Chickpeas (2 mg per 100 g)
  • Yogurt or kefir (1-2 mg per 100 g)
  • Almonds (1.5 mg per 100 g)
  • Spinach (1.4 mg per 100 g)
  • Dark chocolate (1.2 mg per 100 g)

Heavy metals have a variety of impacts on the body, they can damage DNA, brain cells, organs, and cause a variety of diseases. In male fertility heavy metals can

  • Damage the DNA of sperm, which leads to low sperm quality, amount and motility.
  • Disrupt normal hormonal balance > decrease testosterone levels or dysregulate estrogen balance and generally wreak havoc on hormones.

There are heavy metal tests available through a holistic doctor. If you have heavy metal toxicity, the best and most effective method of detox is chelation therapy – the use of chelating agents such as EDTA and DMSA to bind to and remove heavy metals from the body. This should only be done under the supervision of a doctor.

Although there are many herbal methods, supplements and dietary changes that purport to be effective in removing heavy metals for the body, some of them can do more harm then good, and applying them without proper protocol from an expert, can do more harm than good. I recommend bringing any such suggestions to a holistic doctor, or nutritionist (what i’m in school for) and if he agrees using them in concert with chelating agent as part of a proper detox protocol. If you are on any medications or have any pre-existing health conditions, you should contact your physician first.

Studies have proven that some pesticides can have a wide range of negative health effects including damage to DNA and disruption of hormone balance by mimicking or blocking the actions of hormones like estrogen and testosterone, leading to changes in sperm production & function.

Both halogen and glycol can be found in pesticides, while glycol can also be found in some antifreeze, de-icer and other such products. Halogen pesticides like chlorpyrifos and diazinon, and glycol pesticides like methoxychlor can affect male fertility by:

  • Disrupting the normal functioning of the endocrine system and it’s production of hormones
  • Decreasing sperm count and motility
  • Increasing the number of abnormal sperm
  • Cause an increased risk of testicular cancer, which can also impact fertility

If you are trying to conceive and live on a farm, or in a farming community, or your residence is anywhere near where they spray these toxic pesticides, I highly recommend you move far away. I personally know people who have developed various health conditions as a result of living near areas where they spray pesticides.

Otherwise most people living in urban areas / cities can reduce exposure by trying to purchase organic food, and also wearing proper safety equipment when handling vehicular chemicals (or getting a mechanic to maintenance your vehicle for you while trying to conceive). Some foods are more pesticide laden than others find out which on the Dirty Dozen List (click link).

DDT (dichlorodiphenyltrichloroethane) and PCBs (polychlorinated biphenyls) are types of persistent organic pollutants (POPs) that were widely used in the past as pesticides & industrial chemicals, which are now banned or heavily restricted in many countries due to their toxic effects on human health and the environment. They persist in the environment and can accumulate in soil, produce and water which causes them to pass into the food chain.

DDT and PCB exposure can disrupt endocrine system function; they block or mimic functions of hormones like estrogen, and degrade sperm production (sperm count), function (motility) and increase the amount of abnormal sperm. Studies also link DDTs and PCBs with increase risk of testicular cancer, which affects male fertility.

As I stated before I highly recommend relocating if you live anywhere near where farms spray these toxic chemicals, not only are they extremely toxic, but if you are near where they’re spraying you’re going to be exposed to volume beyond what is considered safe and will almost assuredly run into health issues; if not you then your baby!

Otherwise simply try to purchase organic food to reduce exposure. Some foods are more pesticide laden than others find out which on the Dirty Dozen List (click link). Also avoid a diet high in fatty fish and animal products, as these tend to have higher levels of POPs.

Abnormal chances to the size, shape and motility of sperm, can increase chance they won’t be able to swim to or have the energy to penetrate the outer later of thee egg, which lowers chance of successful conception. Also sperm defects can increase risk of genetic disorders or chromosomal abnormalities if an offspring is conceived.

Generally if considering conceiving: one can test sperm count, quality, and motility to gauge if fertility treatments are required and begin taking proactive action to rectify the issue and increase chances of conceiving a healthy offspring.

There are many things one can do to improve the quality and motility of sperm: adequate nutrient intake, avoiding toxins (external and internal), eating a health diet in organic whole foods, practicing safe sex and testing for STI or STDs, avoiding heavy metals in diet or environment and taking actions to detox them from the body, being aware of pre-existing health conditions, talking with your doctor about health issues or medications you are taking when trying to conceive, and limiting or avoiding exposure to the bad things on this list. Also working with your partner to ensure you are both taking the necessary steps to improve fertility and increase chance of conceiving.

The age old debate of boxers vs briefs. Taking a look at male physiology, the testes are located in the scrotum on the outside of the body in order to maintain a lower temperature (optimal is 2-4C below body temp). When testes are excessively heated (aka testicular hyperthermia) it can disrupt the normal sperm production and development, leading to a decrease in sperm count, motility, and quality. Heating can occur through many activities such as: prolonged sitting, tight clothing (briefs), hot baths or saunas, and certain medical conditions e.g. varicocele. Effects are dose-depending so the more severe and prolonged the heat exposure the more it hurts sperm quality and quantity.

Like most other things that can hurt sperm, excessive heat to the testes also increases risk of genetic disorders and chromosomal abnormalities if offspring are conceived.

Obviously I’m not going to tell you to stop using hot tubs and briefs but like anything else moderation is key. If you are trying to conceive look at your lifestyle and make adjustments…if you notice hot tubs or saunas are something you frequent, reduce frequency. Add if you often wear tight clothing, trying buying some loose pajamas or mix in some briefs to wear on some days. For allot of men this probably won’t be an issue, but if it is then take these steps.

Steroids (aka Anabolic Androgenic Steroids (AAS), are synthetic derivatives of the male sex hormone testosterone and taken in high doses can disrupt the endocrine systems normal function, resulting in a number of negative effects on sperm production and function. Primarily steroids suppresses the hypothalamic-pituitary-testicular axis, responsible for testosterone production which reduces sperm count, motility and number of abnormal sperm. But AAS can also negatively impact male fertility via:

  • testicular shrinkage (aka testicular atrophy) which can also decrease fertility
  • increasing risk of certain cancers such as prostate cancer

The fix for this is pretty simple…don’t consume performance enhancing drugs such as steroids, if trying to conceive a healthy baby. If for whatever reason you can’t stop PEDs like steroids, you should work closely with your doctor and a specialist to monitor hormones, especially if you are having trouble conceiving, and your steroid use may be a factor.

Soybeans and soy-based products, such as tofu, soy milk, and soy protein powders, are rich in phytoestrogens; plant-based compounds which mimic the effects of estrogen in the body. Some studies suggest high intake of soy foods can decrease sperm count and motility, while others have not found any significant effect of soy intake on sperm quality however most of these studies are on animals (not humans) and were observational (means cause-and-effect relationship is not established.)

So generally apply a bit of common sense here and if you’re sperm count is low and/or you are struggling to conceive then consider lowering intake of soy foods. If you just want to increase fertility and ensure the best chance of conceiving a healthy baby, perhaps limit soy exposure as well.

If you work at in an office job you aren’t going to be exposed to toxins as much as say a pesticide worker (well an argument could be made Electro-Magetic Frequencies EMF’s), so this may be more of a concern for some than others. Some of the most common workplace toxins include (but not limited too): pesticides, solvents, heavy metals, and radiation. Besides effects on male fertility exposure to these toxins can also increase risk of certain cancers (e.g.: testicular cancer) which obviously can affect male fertility.

Ten most popular jobs with high levels of toxins or pollutant exposure which can affect male fertility:

  1. Agricultural workers
  2. Construction workers
  3. Pesticide applicators
  4. Painters
  5. Welders
  6. Miners
  7. Manufacturers
  8. Truck drivers
  9. Firefighters
  10. Chemical plant workers

I’m not going to tell you to quit your job, but again apply some common sense here and if you’re struggling to conceive, perhaps take some time off, contact your doctor to see if there are any ways you can detox your body, and ensure you are always wearing the best safety equipment.

If you’re boss fails to provide safety equipment and you work in a country/state where there are safety laws/regulations, you have every right to file a complaint with the authorities (which can sometimes be anonymous – just google “YOUR PROVINCE – file workplace safety complaint” and find the state/provincial website. I’ve seen too many irresponsible companies/businesses put profits before the health of their employees where friends of mine have ended up with serious health and neurological issues that will impact them for the rest of their lives. I’m telling you right now no amount of money is worth your health, and although you can get away with quite a bit short term, chronic long term exposure to toxins at your workplace, is going to cost you dearly. If your boss can’t put your health first, he doesn’t deserve to run a business.

I put this already in the section for both men and women, but I put it here again to drive the point home that both of these toxic addictions can affect male fertility and the health of offspring. Usually effects are dose dependent and the mroe you consume the more damage to your sperm:

  • Smoking – studies have shown tobacco use can decrease sperm count, motility, normal morphology and increase risk of abnormal sperm. Studies have also suggested smoking may increase the risk of genetic damage to sperm, which can lead to an increased risk of miscarriage and birth defects.
  • Alcohol – studies have shown excessive drinking is linked to decreased sperm count, motility, and normal morphology.
    • Testosterone production is also decreased which is vital for normal sperm production and health.
    • Oxidative stress is increased by alcohol, which can damage sperm DNA.

I’m not saying you have to quit smoking and drinking indefinitely, but as a man at least reducing intake or taking a break while conceiving, is all around a good idea, especially if you want to ensure a healthy offspring.

factors that affect fertility - what affects sperm count - what affects fertility in females - what affects male fertility - what affects sperm count - what affects fertility - can stress affect fertility - how does stress affect fertility -  conclusion


It’s clear there are many different factors which affect fertility in both men and women: bad habits like smoking, alcohol and caffeine, pre-existing health conditions, some medications, vitamin deficiency or overdosing on supplements, being too thin or over weight. As well exposure to heavy metals, pesticides or chemicals at home or work can affect fertility. Women over 35 may have to be more diligent about nutrition and hormones when trying to conceive, and men need to stay away from things like steroids. Obviously you can’t avoid everything all the time, but like everything moderation is key. If you are struggling to conceive, this comprehensive list might tip you off to things you are doing that are potentially affecting your fertility, which you can then work to improve. Always contact your physician if you have health conditions or are on medications. Also It’s best to work with a nutritionist, or a naturopath or holistic doctor, before supplementing with concentrated vitamins or different herbs. One who can look at your current diet, supplementation and health to create a customized nutrition plan tailored to your unique circumstances, which will ensure the best possible chance of conceiving a healthy baby.

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