Overweight and obesity and infertility

In women, the most common endocrine disorders associated with overweight and obesity are insulin resistance, ovulation disorders and excess androgens. An association of excessively high body weight with endometriosis and polycystic ovary syndrome (PCOS) has also been shown. An excessively high BMI is associated not only with fertility disorders in women, but also with miscarriages and pregnancy complications. This means that being overweight has a negative impact on getting pregnant.

In men with too high a body weight, there is an excess of oestrogen and a deficiency of testosterone. Too high a BMI has been shown to reduce the secretion of growth hormone, which in turn affects the hormones responsible for the production of gametes: in women, ova, and in men, sperm.

Adipose tissue has secretory functions and excessive amounts are associated with the production of inflammatory factors, which can make it difficult to get pregnant. High concentrations of inflammatory factors hinder embryo implantation in women, while in men it is associated with poorer semen quality. Being overweight before pregnancy can thus hinder efforts and cause problems in getting pregnant.

How to deal with obesity while trying for a baby?

Weight reduction in women and men and a proper diet before pregnancy are associated with improved fertility and therefore often become an important recommendation from the treating physician. If you have received or have been given such a recommendation, consult a dietitian from an infertility clinic. Pre-pregnancy weight loss under the guidance of a specialist will be more effective and safer.

A professional dietician, experienced in consulting couples trying to have a baby, will be able to help you achieve your goal. He or she will discuss good and bad eating habits, make specific recommendations and, if necessary, prepare a menu perfectly tailored to your needs and preferences, with a view to both weight reduction and additional fertility support with the right products.

In addition, overweight and obesity during pregnancy pose a risk not only to the mother, but also to the baby. Among other things, the woman may be at risk of gestational diabetes or pre-eclampsia. In the foetus, there is an increased risk of birth defects or neural tube defects and, in the future, the development of metabolic syndrome. There is also an increased risk of premature birth. Obesity can also make natural childbirth more difficult.

Diet before IVF and pregnancy - take care of yourself

Weight reduction in women improves hormonal balance and helps to restore normal ovulatory cycles, it also helps to avoid complications of pregnancy. Weight and ovulation are therefore linked. Women with a BMI of more than 30 kg/m2 are much more likely to have irregular menstrual cycles or non-ovulatory cycles.

In men, hormonal balance also improves as a result of weight reduction, and erectile dysfunction may also be reversed. However, weight reduction should be carried out with caution. Losing weight too quickly can have a negative impact on health and fertility, and in men, for example, can be associated with a deterioration in semen quality. A diet that is too low in calories before pregnancy can be associated with nutritional deficiencies that impair fertility on many levels.

Changing bad eating habits and a proper diet are also important before embryo transfer. Obesity and overweight will reduce the chance of completing the IVF procedure successfully. Too much weight makes implantation more difficult. With weight, the number of pregnancies diagnosed up to 5-6 weeks and pregnancies diagnosed clinically also decreases.

Healthy weight reduction, or how to lose weight healthily

A pre-pregnancy reduction diet should firstly be appropriately calorific. Certainly the caloric content of a reduction diet should not be lowered below the basal metabolic rate (PPM). Setting the calorific value below PPM will be associated with nutritional deficiencies, but also with a slowing down of the metabolism, as too low a calorific value can consequently reduce muscle tissue mass.

How do you calculate PPM, or basal metabolism?

PPM can be calculated using a formula. There are several formulas for PPM, but one of the most reliable is the Harris-Benedict formula, substituting body weight, height and age.

The PPM should be multiplied by the physical activity factor, where, for example, a factor of 1.4 represents a sedentary lifestyle and 2.0 represents hard physical work. This gives us the total metabolism (CPM), which gives a true picture of our daily energy requirements. If you want to reduce body weight, you need to subtract a certain amount of calories from the CPM. It is important to remember that many popular weight-loss diets have calories lower than the PPM, so it is best to entrust the determination of calories and a specific menu to a dietician.

Reducing diets and fertility and trying for a baby?

What's good to eat before getting pregnant? Diet during efforts to have a baby should first and foremost be based on healthy eating principles in order to effectively promote fertility. Such a diet has a high nutrient density and does not involve the consumption of high-calorie products with little nutritional value, i.e. lacking in vitamins, minerals, fibre or antioxidants. Such products provide our bodies with nothing but energy in pure form. Products containing large amounts of simple sugars can even deplete the body of B vitamins, which are needed to metabolise them.

Choose whole grain breads

A good example of low and high nutrient density foods are cereal products. Those prepared from low-value refined flour have a low nutrient density. In contrast, products made from whole-wheat flour provide the body with a range of minerals, including zinc and selenium, fibre and B vitamins.

The diet for those trying to have a baby should include wholemeal products, i.e. wholemeal bread, brown and wild rice, oatmeal, buckwheat groats or pasta made from wholemeal flour. A diet based on such products has a low glycaemic index. This means that energy is released from them t slowly, without causing large fluctuations in blood glucose and insulin levels. One of the positive effects of changing eating habits will be an improvement in hormonal balance.

Exclude highly processed foods

Highly processed foods, which have little nutritional value and may contain unfavourable ingredients such as hydrogenated vegetable fats, preservatives, colourings or large amounts of simple sugars, should be excluded from a reduction diet.

Highly processed foods include, but are not limited to, convenience foods, fast-foods, sweets, confectionery, salty snacks and sugary drinks. Most light products tempting people to lose weight should also be considered as highly processed foods.

Eat vegetables and fruit

Also, fruit juices, especially those reconstituted from concentrate, have little nutritional value, providing large amounts of sugars at one time with a reduced amount of fibre. Many people are still stuck in the belief that such juices are health itself.

A reduction diet to support fertility should include larger amounts of fresh whole fruit and vegetables than fruit juices. In this way, you will provide yourself with far more nutrients and fibre. Products that particularly support fertility are: kale, spinach, broccoli, lentils, peppers, berries, goji berries, currants.

Fruit and vegetables can also be introduced in the form of smoothies in which they are used whole, but this should not be overdone either. Blended meals give a feeling of satiety for much less time.

Choose healthy fats - what to eat for fertility

Other products that definitely need to be limited are those containing trans-fatty acids, i.e. products with hydrogenated oils. These include hard cube margarines, ready-made cakes, sweets, crisps, fast-food and convenience foods. Trans-fatty acids have a pro-inflammatory effect in our body, so they should not be eaten before pregnancy.

Products containing healthy fats such as olive oil, rapeseed oil, flaxseed oil, nuts and seeds, avocados, oily sea fish should be included in the diet. These fats are a source of vitamin E (a powerful antioxidant) and unsaturated fatty acids. Particularly important are omega-3 fatty acids, which have anti-inflammatory properties and are found, for example, in oily sea fish, flaxseed and walnuts.

Drink water

What is often forgotten is the right amount of fluids throughout the day. The water requirement is about 1.5-2.5l per day. It is best to drink plain water, unsweetened fruit teas, rooibos or herbal teas. Black, green or white tea is also allowed, but in small quantities and should not be sipped with meals, as it can interfere with the absorption of minerals. Drinking alcohol is also inadvisable. Alcohol abstinence is required even before a semen test is performed.

Don't snack

A very bad habit that hinders weight loss is snacking between meals. We often do not realise how many unnecessary calories we are able to take in between meals.

During follow-up appointments, when I ask about deviations from the diet I often hear that it was just one chocolate bar, one piece of cake, a handful of crisps, and once there was a kebab... And in the end it turns out that there was 'something' a few times a week and not much left of the energy deficit.

I then recommend counting calories yourself from one or more days for the realisation that sometimes even small amounts of sweets or other snacks disrupt the whole process.

By maintaining a good meal regularity, using high-fibre products and eating plenty of vegetables, we should not feel hungry between meals. In between meals, we should drink water and unsweetened beverages.

Give up frying

As far as cooking techniques are concerned, only high-fat frying is eliminated in healthy individuals. Other cooking techniques are allowed. Frying causes a significant increase in the calorie content and digestibility of the dish.

In summary, in order to safely reduce body weight and improve fertility at the same time, you should:

beware of starvation,
do not eat highly processed foods of low nutritional value,
do not eat products containing hydrogenated vegetable fats,
hydrate yourself,
eat regularly and keep breaks between meals.

BMI and the in vitro procedure

Body height influences success in vitro procedures and interferes with getting pregnant. Not only obesity, but already being overweight, i.e. a BMI above 25 lowers the chance of getting pregnant. It was shown that with a BMI below 25, the pregnancy rate per cycle was 45.5%, and with a BMI above 25, the pregnancy rate was already 38.3%. Higher BMI is associated with poorer follicle growth during stimulation and fewer implantations (Metwally M., Li T.C., Ledger W.L. (2007) The impact of obesity on female reproductive function. Obes. Rev. 8 (6): 515-23).

Lowering body weight reduces the amount of drugs used in the IVF procedure, facilitates ultrasound, and allows more oocytes to be obtained during the LP. It is also important to bear in mind the impact of too high a body weight on pregnancy complications such as gestational diabetes or hypertension.

According to the WHO, a normal BMI of 18.5-24.9 is best for fertility, including that treated by assisted reproduction methods (insemination and IVF).

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MA Adrianna Barczyńska

This article was prepared by Adrianna Barczyńska, a dietician at the InviMed clinic in Katowice, Poland. On a daily basis, she helps patients of the InviMed clinic to choose a diet that may be helpful in infertility treatment. Graduate of the Silesian Medical University in Katowice, majoring in dietetics. Continuously extends her knowledge by participating in many scientific conferences and trainings in the field of dietetics.