How Pre-Pregnancy Lifestyle and Diet Influence Success Rates of Fertility Treatments like IVF

Updated: Mar 31

People often wonder whether they can try to improve fertility. While some medical issues are beyond control, the science is clear that lifestyle choices have an effect, too. Here's how individuals can promote and protect fertility - and how that can lead to improved pregnancy rates.

About this special series


This month marks the launch of ELANZA Wellness’s Whole Patient Care Initiative, in which we are drawing together a combination of clinician commitments to build patient-centric experiences with patients’ personal stories that shed light on some of the big questions about how to improve fertility care.


As part of this initiative, ELANZA is looking at five key topics that relate to the strengths and weaknesses of existing fertility services, the state of access and inclusion, patient’s expectations of care and the potential of technology to change things for the better in future. This special series of articles includes:


1. Mental and emotional health

2. Diversity, equity & inclusion

3. Lifestyle factors

4. Patient-centric operations

5. How clinics can improve patient care


This initiative and the reports we will produce are intended to inform the global conversation about the past, present and future of fertility care.

Pre-Pregnancy Lifestyle, Diet and Fertility

Lifestyle changes in the preconception period are all focused on making our bodies healthier and our emotional state happier. There are three scientifically identified factors that influence the ability of your ovaries to produce quality eggs as you age. These are: oxidative stress, hormonal balance and energy production. All of these three factors can be influenced by the foods we eat, what we put in, on and around our bodies and our mental and emotional wellbeing.


Let's take a look at these key factors for fertility in more detail:


Oxidative stress

Oxidative stress in your cells is caused by the overabundance of molecules called free

radicals, which can cause damage to the cells in your ovaries. It can impact fertility by dis-regulating hormones, causing damage to energy-producing centers in cells (mitochondria) and by causing DNA and cell damage.


Hormone balance

Reproduction as a whole is a finely tuned process run by a sophisticated balance of

interacting hormones. These hormones work like a symphony orchestra, each playing a subtle

role in concert with the others - so if one hormone plays out of tune, it can disrupt the entire

performance. In other words, if the signals hormones send are disrupted, left unsent, or are

unable to be received at any point while your eggs are growing, your ovaries won’t receive the message to carry on with the key phases of chromosomal processing. Meaning: they may not become quality eggs.


And, achieving the right balance of hormones needed to send the right signals is harder than

you think, especially as you get older. As you age, your ovaries become less responsive to

hormone messages from the brain, leaving more opportunities for disruption.


Energy production

Your growing eggs need an incredible amount of energy to get safely through all the stages

of chromosomal processing. They get this energy from mitochondria, which are the tiny “power

plants” in your cells. As you age, your mitochondria decline both in quantity and in power supply. When there isn’t enough energy to fuel egg maturation and chromosomal processing it can result in low quality eggs. Scientists think certain lifestyle habits may protect mitochondria from or expose them to damage.


“As a clinician, I've seen plenty of women who have had undesirable results from their first egg retrieval, and then take three months to focus on specific health and lifestyle modifications before going back for another cycle. Almost every single time, the woman gets more egg retrieved and the embryos are better quality." - Dr. Jenn Shulman, Jennifer Shulman Acupuncture, New York and Los Angeles


1. Is the Mediterranean diet really linked to fertility?

Diet can have a profound effect on the maturation, development and quality of eggs. In fact, what you eat is so instrumental that some scientists believe that nearly half of all cases of infertility are due to improper nutrition.


Hundreds of studies show that specific dietary patterns translate to better fertility treatment outcomes, such as higher quality eggs, higher number of eggs retrieved increased pregnancy rates and lower risks of miscarriage - and that certain lifestyle patterns can affect the menstrual cycle and reproduction. A Harvard study reported that women can decrease infertility risk due to ovulation disorders by 80% with healthy dietary changes).


There is resounding evidence that the right foods help:


Maintain hormonal balance

Reproductive hormones are synthesized in the body by

proteins and fats from food.


Limit oxidative stress

A poor diet with lots of fried and processed foods can cause

oxidative stress around your eggs and ovaries, while some foods have antioxidants that

can help protect against it.


● Supply essential nutrients

Key proteins oversee DNA processing during egg maturation, many of which can only come from dietary sources.


Regulate sleep patterns

Dietary patterns may help regulate sleep and improve sleep quality, which can affect your hormones and ovulation.


Boost cell energy:

Compounds in certain foods fuel your mitochondria.


Help you maintain optimal weight

A balanced, nutrient-rich diet with healthy fats can help maintain fertility-friendly bodyweight (BMI of 20-25)


● Stabilize blood sugar levels

Elevated blood sugar levels caused by foods with a high glycemic load (GL) can cause ovulatory dysfunction.


● Regulate stress

Diets low in sugar and junk food are linked to better moods. And the relationship goes the other way, too. The stress hormone cortisol triggers blood sugar and insulin levels to rise in order to give you the energy to “fight or flight” from a stressful situation. When you are chronically stressed, this can lead to insulin resistance, which disrupts the balance of hormones needed to properly mature your eggs.

So what should we eat?

The Fertility Diet created by Jorge Chavarro and Walter Willett from Harvard School of Public health is designed to boost ovulation and improve fertility. This is essentially a Mediterranean diet, focusing on vegetables, fruit, healthy fats, lean protein, nuts, seeds and whole grains, while avoiding sugars (including artificial sweeteners), simple carbohydrates, fast food, and packaged food. Try to fill half your plate with vegetables and some fruits, and avoid “empty” calories.


How to eat the Mediterranean way:


● Eat foods closest to their natural form.

● Try to get more of your protein from vegetables and fish, rather than red meat.

● Pick foods with a low glycemic load (GL).

● Mix up your meals your meals to make them richer in vitamins, minerals and

antioxidants for egg health.

● Consider taking a probiotic (namely lactobacillus acidophilus). New research is focusing on the role that vaginal bacteria could play in pregnancy and fertility treatment outcomes, too. So, it's worth making sure your diet is rich in pre and probiotic foods.



2. The "Goldilocks" body composition zone for fertility

While culturally, artistically and romantically, there’s no right or wrong amount of body fat, medically-speaking we’re on different territory. Scientists have pinpointed an optimal "Goldilocks" zone for fertility, and that's a body mass index (BMI) of 20-25.


High body fat percentage

30% of infertility has been associated with weight extremes, and infertility rates are 3 times higher in women with obesity.


The amount of body fat we have can impact reproductive systems because fat cells produce

and store estrogen, in addition to the estrogen already being produced in our ovaries. As such, the more fat cells the more excess estrogen. This can have a domino effect on other hormones, throwing them out of balance and leading to reproductive issues such as irregular ovulation. Being overweight also influences other factors that are problematic for reproduction, including stress, lack of sleep, oxidative stress and insulin resistance. Insulin resistance causes the body to release more insulin which can halt ovulation.


Research suggests that overweight and obese women are

much more likely to experience:


  • Anovulation

  • Menstrual disorders

  • Infertility

  • Lower IVF and egg freezing success rates

  • Higher rates of miscarriage

  • Pregnancy complications

Most studies show that obese women going through IVF tend to have fewer eggs retrieved, fewer mature eggs, and poorer egg quality compared to women who are not overweight or obese. The same is true for men: body fat can influence testosterone and other hormone levels that can affect sperm count and sperm mobility.


Low body fat percentage

Underweight women can often suffer with ovulation problems as well. The data suggests that having a BMI of 20 or less also comes with a higher risk of infertility and pregnancy complications.


Women with a BMI under 20 are more likely to have:


  • Ovulatory disorders

  • Higher risk of miscarriage

  • Ovarian dysfunction

  • Pregnancy complications such as preterm birth


This happens partly for the exact same reason as for high body fat percentage: key sex hormones like estrogen are produced and stored in fat cells. So, just as heavier women produce excess estrogen, women who have less of what’s been coined “sex fat” (tissue where sex hormones are stored) can experience lower-than-optimal estrogen levels.


Being very slim can also inhibit the production of other key fertility hormones such as

leptin, which is thought to give ovaries the green light to function. This is most likely because leptin plays a role in the regulation of energy balance (how many calories you eat, burn and store as fat) and is produced and stored in fat cells. So, when fat cells are in short supply, leptin signals to your body that the conditions are inadequate for reproduction.


Gradual changes are best

The good news is that even a 5% reduction in weight has been shown to improve fertility.. But It’s important not to try to make drastic lifestyle changes overnight, as this can put your body under a great deal of stress. For example, if you are severely overweight or underweight, a 20% rapid gain or loss in the opposite direction could cause menstrual irregularities and cause a hormonal imbalance. Taking your time to make healthy and steady lifestyle changes that are sustainable over time is by far your best strategy.


BMI

There are plenty of free online BMI measurement tools that can help see if you fall into a fertility-friendly bodyweight.


BMI is a notoriously tricky thing, of course, which is why sometimes it's more practical to talk about body fat percentage. You can discuss this with your own doctor, or you may wish to talk to a qualified nutritionist, dietician or naturopath.


"Having structure with meal planning will help you if you are struggling with weight gain and weight loss. This will be a great way to create a foundation for if and when you do seek to get pregnant. I also encourage women who struggle with eating too much and too little to adopt a few techniques that stem from the practice of mindful eating on listening to hunger cues (feeling full or hungry), eating slowly without distractions, and appreciating your food.” - Elizabeth Stanway-Mayers, Clinical Dietitian, Stanford University Medical Center


3. Smoking, Drugs, Caffeine & Alcohol

Alcohol


When it comes to the impact that alcohol can have on IVF success rates, most studies

indicate that alcohol is fine to a point. However, the point at which negative repercussions appear varies from study to study: one study indicates that up to 12 grams of alcohol per day is fine (the standard American drink is 14 grams!) and others say that fewer than four drinks per week is ok. Another concluded that women who drank more than seven drinks per week were just two percent less likely to have a live birth per cycle than non-drinkers, so the difference may not be big enough to be significant.


Smoking

One of the most colossal changes you can make for your short and long-term fertility is to

quit smoking. It can reduce fertility by 60%. It’s linked to:


  • Irregular periods

  • Diminished ovarian reserve

  • Earlier menopause (one to four years earlier)

  • Every year of smoking has been shown to increase the risk of unsuccessful IVF by up to 9%

  • Risk of miscarriage increases by 1% per cigarette smoked per day.

  • Lower egg quality in IVF

  • Lower implantation rates

  • More cycles with failed fertilization compared to non-smokers. This is also supported by research showing that women who smoke are more likely to conceive a chromosomally unhealthy pregnancy (such as a pregnancy affected by Down syndrome) than non-smoking mothers.


One culprit is a group of chemicals called polycyclic aromatic hydrocarbons (PAHs) found in

cigarette smoke are known to accelerate the destruction of your eggs by causing DNA damage to the ovarian follicles, where the eggs normally develop to maturity.

It’s unclear how much of the damage is reversible but one large study showed that when

women stopped smoking, the risk of earlier menopause decreased. What is clear is that the sooner you quit, the better it is for your fertility.


The same goes - to a lesser degree - for secondhand smoke, vaping and e-cigarettes.

DOCTOR INSIGHT: “Smoking is one of the worst things for egg quality. Stop sucking on the egg killers is what I tell my patients. Describing how nicotine levels can literally be measured in a smoking woman's ovaries is a quick way to get someone to quit.” - Dr. Aimee Eyvazzadeh, Private Practice Physician, San Ramon

Caffeine

It used to be thought that caffeine had a purely harmful effect on fertility, but as more data

from large studies has emerged, conflicting results have made the link less clear - with some

showing no negative impact at all.


The key might lie in the amount of caffeine consumed. The present thinking is that while

low to moderate caffeine consumption has not been shown to have a negative effect on fertility

treatments, moderate to high intake could be harmful to your eggs. Support for this comes from studies in which women who consume large amounts of caffeine have been shown to experience:


  • Longer time to get pregnant

  • Increased rates of miscarriage

  • Higher rate of spontaneous abortion

  • Higher rate of fetal death and stillbirth

  • Decrease in quality embryos.



The rates seem to rise the more we drink - over four cups being problematic.

The exact biomechanics of caffeine’s impact on fertility are still unknown; however, there

are a few passageways that can offer us clues. First, caffeine magnifies your body’s stress

response, raising blood pressure and noradrenaline even at rest, which could have a knock on

effect to reproductive hormones. Second, when you drink caffeine close to mealtime, it can interfere with your body’s ability to absorb key minerals like zinc and iron from your food. It’s also theorized that high amounts of caffeine could restrict blood flow to the ovaries and womb, though this could also be due to some other substance present in coffee but not in other caffeine sources such as green tea.


Cutting it out completely is not considered necessary. Instead, doctors commonly advise to limit caffeine consumption to one to two cups per day - around 200mg of caffeine.


Overall:


  • Quitting smoking will likely have benefits for fertility outcomes

  • There's evidence to suggest limiting caffeine consumption, try naturally caffeine free teas.

  • There's also evidence to suggest limiting alcohol consumption - if you do drink, opt for red wine with a low GL meal.


4. Toxins



Many scientists now believe that the vast and growing use of noxious substances in the typical modern home and workplace could be partly to blame for the widespread decline in fertility for both women and men. These so caled "endocrine disrupting chemicals" (EDCs) have the ability to disrupt reproductive

hormones and to damage maturing eggs.


Hazardous chemicals to your fertility can be found in your cleaning products, kitchen

tools and beauty products. There are also strong links made between pesticides, preservatives and other chemicals in our daily environment.



Some of the most well known chemicals to cause reproductive damage are:

○ BPA - found in plastics, canned food containers, feminine hygiene products

○ Phthalates - found in plastics, medication coatings, cosmetics with fragrance

○ Parabens - found in cosmetics, toothpaste, processed food, face and hair care

products

○ Pesticides - found in drinking water, “dirty” foods, air supply near agricultural

areas

○ Heavy metals - Found in cigarettes, pollution, high mercury fish, household dust



BPA

One example is BPA - most famously known as the “gender-bending” chemical due to its effects on male breast growth (or, as you might know them, “man boobs”) and reduced penis size in newborn male infants. But more on the subject of you, BPA exposure is consistently linked to negative reproductive outcomes such as fewer eggs retrieved, fewer mature eggs and fewer fertilized eggs for women undergoing IVF. In fact, 139 different research studies indicate that BPA disrupts the egg maturation process and reduces egg quality.



Here are some simple changes to make to start reducing exposure:



● Get a water filter


● Throw out old and scratched plastic items


● Replace plastic Tupperware with glass


● Don’t heat up plastic


● Don’t consume foods from cans - BPA is often found in the lining of cans.


● Say no to printed receipts - Thermal paper is often coated with BPA.


Avoid products with fragrance or perfum - look for labels that say “phthalate-free”

or “no synthetic fragrance” instead.


● Ditch fast food


● Reduce consumption of foods packaged and stored in plastic - and swap out plastic containers for glass or stainle