Environmental Toxins and Fertility

November 1, 2019

There’s been more awareness over the years about environmental toxins and their impact on our health. A recent study came out in Fertility and Sterility about their impact on fertility and pregnancy – and I’ve summed up the major points for you. 


When we think about mercury exposure, fish usually comes to mind. This is because mercury is a by-product of industrial processes like coal burning and waste incineration. Fish can absorb mercury from seawater and from the prey they eat. This means that big fish usually have more mercury than little fish (because they eat more little fish). And big fish also live longer, meaning more mercury accumulation. So, if you eat fish high mercury levels, this will put you at risk for mercury exposure. 

Pregnancy Risk 

Mercury can cross the placenta and accumulate in your fetus, leading to higher levels compared to yours. Low levels of mercury in pregnant women are associated with lower IQ scores in their children.  

What to think about

  • How often do you eat fish?
  • Do you use personal care products with mercury?
  • Do you use mercury thermometers?
  • Do you work with mercury?


Don’t be scared about fish because not all fish is bad and fish is great source of protein. That said, it’s important to be mindful about the type of fish you’re eating. 

High mercury fish include:

  • Fresh/frozen tuna
  • Shark
  • Swordfish
  • Marlin
  • Orange roughy
  • Escolar

Health Canada advises that if you’re pregnant, planning on becoming pregnant, or are breastfeeding you should limit consumption of these particular fish to 150g per month.

If you’re pregnant, planning to become pregnant, or are breastfeeding, canned albacore (white) tuna consumption may lead to mercury exposure. This is should be limited to 300g per week. However, this doesn’t apply to canned light tuna, which is relatively low in mercury.

Overall, this doesn’t mean you need to limit the amount of fish that you eat. Health Canada recommends to continue eating at least 150 grams (5 ounces) of cooked fish each week during pregnancy.

Fish that contain lower amounts of mercury are:

  • Salmon
  • Trout
  • Herring
  • Haddock
  • Canned light tuna
  • Pollock (Boston bluefish)
  • Sole
  • Flounder
  • Anchovy
  • Char
  • Hake
  • Mullet
  • Smelt
  • Atlantic mackerel
  • Lake white fish


Many years ago, lead was used in gas, paint, and pipes. If you live in an older home, you’re at risk for lead poisoning – especially if you’re remodelling and renovating your home. Lead can also be found in jewellery, make up products and toys. 

Pregnancy Risk 

If you’re pregnant, high lead levels are associated with pregnancy-related high blood pressure, preterm delivery, low birth weight, miscarriage, birth defects and abnormal placenta formation. It may also affect intellectual development in kids. 

Have you been exposed?

  • Are you living in a home build before 1978?
  • Are you renovating it?
  • Do you use imported pottery when cooking?


It can be hard to reduce exposure, especially if you’re living in a home built before the eighties. Not to mention, recommendations stay not to renovate – which isn’t always feasible!

There are some things you can do to avoid lead exposure though. Avoid using cosmetics made with lead (lipstick can be one of them, so you may want to switch up brands), and don’t cook with lead-glazed pottery.


This is a heavy metal used in rechargeable batteries, paint pigment, and in plastic production. It enters food through soil, and can be found in shellfish, organ meats, rice, wheat, leafy greens, potatoes, and celery root. Smokers and nonsmokers are exposed to cadium through tobacco smoke.

Fertility Risk

Cadium can accumulate in the ovaries and lead to a decline in progesterone and hCG production. Researchers have found that it can also affect IVF outcomes, as it can result in decreased fertilization and implantation. It also acts as an endocrine-disrupting chemical, and can mimic and inhibit estrogen and lead to abnormal hormone levels and irregular cycles.

In men, high cadium levels may affect sperm quality, decreased motility, and decreased testosterone levels.

Pregnancy Risk 

If you’ve been exposed to cadium, it can accumulate in the placenta and is associated with preterm delivery, and can be found in breastmilk. It also competes with essential metals like zinc and copper – which are needed for fetal growth and development.

Have you been exposed?

  • Do you eat organ meats?
  • Are you exposed to tobacco smoke?
  • Do you buy organic produce?


Because smoking can lead to an increased risk, if you haven’t considered quitting, now might be the time – for the benefit of both you and your partner.

If possible, buying organic rice and produce (especially if you eat some of the above quite often), and avoiding organ meats if you’re trying to get pregnant/are pregnant. See my notes about organic produce in the pesticides section.


In the US, over 1 BILLION pounds of pesticides are used yearly, and can persist in the environment for years – eventually contaminating our soil, food, water and air.

Fertility Risk

Studies show that women who ate more fruits and vegetables with high pesticide residues, had a greater risk of pregnancy loss than women who are low-pesticide residue fruits and vegetables.

Pregnancy Risk 

In the preconception period, pesticides may lead to intrauterine growth restriction and low birth weight.

Have you been exposed?

  • Do you use pesticides around your home or on your pets?
  • Do you buy organic produce?


If you can, choose organic when possible. This doesn’t mean that everything in your fridge and pantry need to be organic though.

Every year the Environmental Working Group comes out with a list of the foods that are highly contaminated with pesticides called the Dirty Dozen. Because choosing organic produce can be expensive, if you find yourself frequently eating any of the foods on the Dirty Dozen list, consider their organic counterpart. Grocery stores like Costco commonly sell organic produce for much cheaper than others. I usually pick up all my berries and leafy greens from there.

Also, there are foods that you don’t need to worry about being organic. These are called the Clean Fifteen.

One last note about choosing organic products. Not only is it important that a product says it’s organic, it should have a Canada Organic, EcoCert Canada or USDA Organic seal. If it doesn’t have any of those, it may not be truly organic.

Endocrine Disrupting Chemicals (EDCs)

These are chemicals that can block or mimic your body’s on hormones. The most common EDCs are:

  • Bisphenol A (BPA)
  • Phthalates
  • Polybrominated diethyl ethers (PBDEs)

All 3 have been found in food, personal care products, plastics and dust.

BPA is used in plastics, canned food liners, receipts. It can be found in plastic baby bottles, pacifiers, toys, and reusable food and drink containers. We are all exposed to BPA on a daily basis, and in the US, 93% of people have detectable levels of BPA in their urine.

Phthalates are used as plasticizers in personal, medical, and consumer care products. Urinary levels are higher in people who eat out, compared to cooking at home. Women with endometriosis have been show to have higher phthalate levels.

Polybrominated diethyl ethers are used in flame retardants on upholstered furniture, textiles, carpeting, and some electronics. Exposure can come from dust brought into your home from shoes and outerwear.

Fertility Risk

BPA has been shown to affect oocyte quality, implantation, embryo development and placenta formation. Higher levels were also associated with miscarriage. In women going through IVF, urinary BPA levels were associated with fewer eggs retrieved. In men, BPA was associated with decreased sperm quality.

Women undergoing IVF with higher phthalate levels had a lower number of retrieved eggs, lower pregnancy rates, and higher risk of early pregnancy loss before 20 weeks gestation. In men, phthalates can cause sperm damage, and is associated with abnormal sperm parameters like motility.

High levels of PBDEs are associated with pregnancy loss.

Pregnancy Risk 

In utero exposure to phthalates has been associated with delivery at an earlier gestational age.

Have you been exposed?

  • Have you purchased new curtains, rugs, and furniture with flame retardants?
  • Do you frequently clean the dust in your home?
  • Do you take off your outdoor shoes before walking through your home?


Consider reducing your use of plastic containers (for both food and drink) and reheating them. Switch to glass and stainless steel instead. If possible, consider cooking at home more often rather than eating out.

Avoid canned foods that have the number 7 stamped on the bottom. Choose personal care products that are fragrance free.

One of the recommendations for avoiding PBDEs is avoiding purchasing new furniture – but this is not feasible at times. You may want to open your windows when it’s comfortable to do so and let the air circulate. Don’t walk inside with your outdoor shoes, and wash your hands when you come in from outside.

Air Pollution

Air pollution is pretty hard to avoid considering it’s everywhere, in particular high traffic places.

Fertility Risk

Elevated air pollution during the preconception period was associated with a higher risk of pregnancy loss.

Pregnancy Risk 

Air pollution has been associated with spontaneous pregnancy loss, preterm delivery, low birth weight, and stillbirth.

Have you been exposed?

  • Do you live in a high traffic area?
  • Are there wildfires in your area?


If possible, avoid outdoor activities when the air quality is poor, use a HEPA filter inside your home to reduce chemicals from air pollution.

Next Steps

There’s a lot to unpack with this study, and it seems that no matter what we do, there’s an environmental toxin wherever we turn. From my perspective, it may be best to address what we can address, and try not to worry too much about things we have no control over. For instance, it doesn’t seem feasible to get rid of a 2 year old carpet, but I can make sure to air out my home and vacuum on a regular basis.

At the end of the day, evaluate your daily routine and see which small changes you can make. If your’e drinking out of plastic on a daily basis, buy a glass or stainless steel water bottle if you can. If you’re a strawberry lover, make sure they’re organic. Litter changes still count!


Segal, T., & Giudice, L. (2019). Before the beginning: environmental exposures and reproductive and obstetrical outcomes. Fertility And Sterility112(4), 613-621. doi: 10.1016/j.fertnstert.2019.08.001

Fertility and Hypothyroidism

August 1, 2019
fertility hypothyroidism, fertility hashimotos, conception, ovulation, toronto naturopath, naturopathic doctor toronto

Becoming and staying pregnant can be difficult (and heartbreaking if the latter occurs). Oftentimes we don’t know exactly why miscarriage happens, but we do know about the involvement of the thyroid in some women. Recent studies have looked at the association between fertility and the thyroid gland and found that conditions like hypothyroidism and Hashimoto’s Thyroiditis are contributors to infertility. 

Thyroid disorders may affect your period in the following ways:

Hormones such as thyroid stimulating hormone (TSH) and thyroid hormones (T4 and T3) are important for menstrual regularity, egg development and implantation. 


Hypothyroidism occurs when TSH levels are increased beyond their normal limits, when there is not enough T4 secretion, or when there isn’t enough conversion of T4 to T3. The latter means that you can have NORMAL TSH levels but T4 and T3 could be off.

Hypothyroidism signs and symptoms look like:

  • Low metabolism, which can lead to weight gain
  • Low basal body temperature
  • Low pulse or blood pressure
  • Dry and/or scaly skin
  • Dry hair and/or hair loss
  • Slowed reflexes
  • Intolerance to cold
  • Depression

Hashimoto’s Thyroiditis

Hashimoto’s is essentially an autoimmune version of hypothyroidism. It occurs when the body doesn’t recognize the thyroid gland as its own and attacks it, leading to the production of thyroid antibodies such as anti-TPO and thyroglobulin.

Additionally, there is also a connection between Hashimoto’s and gluten sensitivity/celiac disease. So if you’ve been looking for a reason to limit your gluten intake, here it is!

TSH During Pregnancy

During pregnancy, having ideal levels of TSH and thyroid hormones is important because they are associated with increased gestation (time between conception and birth), hypertension, growth restrictions, premature delivery and fetal hypothyroidism. It’s clear that the thyroid should be monitored throughout pregnancy.

Thyroid Testing

The American Thyroid Association recommends that TSH should be checked in all women experiencing infertility, and some groups indicate that TSH should be equal to or less than 2.5mIU/L to reduce miscarriage risk.

Here’s the thing though, usually only TSH will be tested but this isn’t good enough! It’s important to understand everything that’s going on with the thyroid so ask for a comprehensive workup that looks like:

  • TSH
  • T4
  • T3
  • Anti-TPO
  • Thyroglobulin

Thyroid and IVF

IVF can be a stressor to the thyroid. And although no studies have showed that treating hypothyroidism leads to an increase of live births, one study has shown that hypothyroid women have less of a response to ovarian stimulation and a lower rate of embryo transfer.

Next Steps

With infertility being so common nowadays, it’s important to take a good look at the thyroid – especially if you have a family history of thyroid disorders or experiencing any of the above signs or symptoms.

Treating thyroid conditions does not just require medication, particular nutrients like selenium or Vitamin D can also be helpful, as well as trying out some dietary changes if you happen to have high antibody levels. Speak to your naturopathic doctor to see how they can complement your treatment plan.


Busnelli, A., Somigliana, E., Benaglia, L., Leonardi, M., Ragni, G. and Fedele, L. (2013). In Vitro Fertilization Outcomes in Treated Hypothyroidism. Thyroid, 23(10), pp.1319-1325.

Biondi, B., Cappola, A. and Cooper, D. (2019). Subclinical Hypothyroidism. JAMA, 322(2), p.153.

Maraka, S., Singh Ospina, N., Mastorakos, G. and O’Keeffe, D. (2018). Subclinical Hypothyroidism in Women Planning Conception and During Pregnancy: Who Should Be Treated and How?. Journal of the Endocrine Society, 2(6), pp.533-546.

Green, K., Werner, M., Franasiak, J., Juneau, C., Hong, K. and Scott, R. (2015). Investigating the optimal preconception TSH range for patients undergoing IVF when controlling for embryo quality. Journal of Assisted Reproduction and Genetics, 32(10), pp.1469-1476.

Orouji Jokar, T., Fourman, L., Lee, H., Mentzinger, K. and Fazeli, P. (2017). Higher TSH Levels Within the Normal Range Are Associated With Unexplained Infertility. The Journal of Clinical Endocrinology & Metabolism, 103(2), pp.632-639.

Sex and your Fertile Window

May 4, 2019
sex fertility, conception, ovulation, toronto naturopath, naturopathic doctor toronto

If you want to get pregnant, you might be wondering when the best time to have sex is, and how often you should have it to achieve a pregnancy.

Timing Sex

Your fertile window can be generally thought as a 6 day period, with the last day being ovulation. Pregnancy chances increase when you have increased sex during this period, and it may result in pregnancy when it happens at least 2 days before ovulation.

It’s important for you to know when you ovulate – and you may want to begin to think about finding this specific day before you start trying. First of all, you shouldn’t be relying on your period-tracking app to tell you when you ovulate. Instead, you should be paying attention to signs your body is sending you.

  1. Cervical fluid
  2. Cervical position
  3. Basal body temperature

A study has shown that tracking your cervical fluid changes across your cycle, can predict ovulation as well or better than basal body temperature and LH strips.

What you’re basically looking for is egg white cervical fluid, that will give you a tip that ovulation is set to occur. Cervical mucus will increase 5-6 days before ovulation and will reach its peak 2-3 days before ovulation.

Sperm and Sex

If a man has normal sperm quality, daily sex won’t impact sperm concentration and motility will reman normal. A study also indicated that men with a low sperm count, sperm concentration and motility may be highest with daily ejaculation.

If you were to space out sex, and your partner is ejaculating every other day, this wouldn’t negatively impact his sperm parameters. However, if he’s ejaculating every 5 days, sperm parameters at this point may be affected. By 10 days without ejaculating, sperm parameters begin to deteriorate.

The bottom line is, as long as sperm parameters are normal (and you probably wouldn’t find this out until after getting tested by a fertility clinic), having sex every 2-3 days in your fertile window can be beneficial.

One study showed that having sex daily, led to a higher chance of becoming pregnant in the menstrual cycle. That said, planning sex for fertility purposes may be emotionally taxing, so select an interval that works best for you and your mental health.

Final Thoughts

It’s important to note that even if you’re having sex daily in your fertile window, this may not lead to a pregnancy – and it may have you worrying about infertility. Keep in mind that 84% of couples get pregnant within 1 year of trying, while 92% get pregnant within 2 years of trying.

The 2 week wait time can be incredibly stressful. If you can’t talk to your partner or friends about this, there are certainly people you can talk to about to help you get you through this journey.

Furthermore, support also exists in helping improve your chances at pregnancy.


Optimizing natural fertility: a committee opinion. (2013). Fertility and Sterility, 100(3), pp.631-637.

Thurston, L., Abbara, A., & Dhillo, W. (2019). Investigation and management of subfertility. Journal Of Clinical Pathology72(9), 579-587. doi: 10.1136/jclinpath-2018-205579