Fertility and High Blood Sugar: What’s the Connection?

Author: Lana Hindi, BASc in Applied Human Nutrition (candidate)

Reviewed by: Dahlia Abou El Hassan, MScFN, RD

For many people, fertility can feel like a mystery, shaped by so many factors we might not be able to pinpoint. However, there are known factors that may contribute to fertility challenges, including high blood sugar.

Whether you have diabetes, PCOS, or other chronic conditions that result in high blood sugar, challenges with fertility might arise. However, it is possible to support both your blood sugar and hormones through diet and lifestyle changes.

But firstly, let’s understand how high blood sugar affects your hormones.

Effects on Women

Firstly, high blood sugar may lead to hormonal imbalances, which can impact ovulation. High blood sugar often leads to insulin resistance, and too much insulin can produce more androgens than the female body needs, such as testosterone, which may interfere with ovulation. This is why PCOS is one of the leading causes of infertility. Egg quality may also be affected. High blood sugar can lead to oxidative stress, which may damage DNA in eggs (also known as oocytes). Interestingly, elevated insulin can cause reduced endometrial receptivity in the uterine lining (the inner part of the uterus), which may interfere with implantation.

Effects on Men 

High blood sugar and insulin can negatively impact sperm quality, including motility, concentration, and DNA integrity. If these are affected, there may be a lower chance of conception. Similar to impacts on egg quality, high blood sugar in males also increases oxidative stress in sperm, damaging them further and impacting fertility. Men with chronic high blood sugar, specifically with diabetes, may face challenges such as lowered testosterone and erectile dysfunction, both of which may also contribute to infertility. 

Now you might be wondering if these mechanisms might impact those undergoing in vitro fertilization (IVF)? It can. So whether you are trying to conceive (TTC) without medical intervention or undergoing IUI and IVF treatment, it’s helpful to understand what’s happening in our bodies and how we can support ourselves as best we can.

Supporting fertility while managing high blood sugar: 

1. Healthy Diet

   • Consume a diet mainly from whole foods and minimize processed foods. For instance, choosing whole-grain pasta over white pasta. 

   • Prioritize lean protein sources such as trimmed beef, poultry, legumes and seafood.

   • Incorporate fibre to support satiety and gut health. Rich sources include fruits, vegetables, legumes and whole grains. 

   • Say yes to fats! Incorporate healthy fats such as olive oil, avocados, nuts, and more. 

   • Enjoy low-glycemic index foods and limit high-glycemic index foods such as refined grains and refined sugars (see graphic for some examples) 

   • Work with a dietitian for personalized guidance.

2. Manage Stress 

   • High cortisol may interfere with both male and female fertility. It can also make managing high blood sugar more challenging.  

   • Practice mindfulness or meditation. 

   • Adequate sleep: Discuss with your healthcare provider about your individual sleep requirements. 

   • Seek social support from friends and family 

   • Spend time outdoors daily. Go for a walk, hike, or do winter activities on snowy days. 

   • Seek professional support, such as a counsellor or therapist, to help you navigate. 

3. Regularly check in with your healthcare provider for blood sugar monitoring and adjust your management as needed

• Before starting any fertility treatment, ensure FBG (fasting blood glucose) and A1C are checked.

4. Engage in regular physical activity 

   • Focus on consistency, not intensity. 

   • It can be as simple as a daily 20-minute walk.

   • Make movement enjoyable: Plan a weekly volleyball, tennis, or other fun activity with friends to stay active, such as yoga and dance.