13 questions about lifestyle and fertility answered by a professor

Wawa talked to professor at Aalborg University and Aalborg University Hospital, Ulrik Schiøler Kesmodel about lifestyle and fertility and asked him 13 questions from our community. Read the answers here.

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wawa fertility

04. oktober - 2022

1) How much caffeine can/should you consume during fertility treatment? Is there a difference between males/females?

The Danish Fertility Society recommends that men and women drink about 400 mg of caffeine daily, equivalent to 4 cups of coffee, while trying to achieve pregnancy. This is a prudent limit. Most studies show that you can drink 5-6 cups a day without affecting fertility, no matter what method you use to get pregnant. The problem for women arises once they are pregnant. That's when even one cup a day increases the risk of miscarriage. So once pregnant, cut back drastically to less than 1 cup of coffee daily.

2) Is there a benefit to cutting out coffee altogether?

No - not if you like coffee. Denmark is one of the countries where we drink the most coffee per capita; consuming up to 4 cups a day does not affect fertility, regardless of how you get pregnant. So don't be a total abstainer if you enjoy coffee. Instead, cut back to less than 1 cup a day once you are pregnant. Even a single cup a day appears to increase the risk of miscarriage.

3) Why are there so many different recommendations about coffee intake?

This is a really good question. Science indicates that as a woman, you should drastically cut down to less than 1 cup of coffee a day once pregnant. The Danish Fertility Society recommends that men and women drink about 400 mg of caffeine daily, equivalent to 4 cups of coffee (8 cups of tea), while trying to get pregnant. Pregnant women should cut back drastically to less than 1 cup of coffee daily because caffeine increases the risk of miscarriage. This was the finding in a pooled analysis of all the studies on the subject.

Nonetheless, the Health Authority guidelines state pregnant women should drink no more than 2 cups of coffee daily. It is unclear why they would not apply this principle to coffee (and other caffeinated drinks) when they use it in different contexts. It reflects attitudes and is a political decision.

4) How does caffeine in energy drinks affect sperm quality?

To the extent that caffeine affects sperm quality, it does not matter where the caffeine comes from. So it doesn't matter if you drink coffee, tea or energy drinks or eat dark chocolate. It's the amount of caffeine that matters. The Danish Fertility Society recommends that men consume no more than 400 mg of caffeine daily, equivalent to 4 cups of coffee. What that equates to in energy drinks depends on which energy drink you use. Look at the label.

5) Should my boyfriend cut down on Pepsi max to boost his sperm quality? And does Pepsi max affect my eggs before ovulation?

On average, regular coke contains about 150 mg of caffeine per litre, equivalent to 1,5 cups of coffee. The Danish Fertility Society recommends that men and women drink about 400 mg of caffeine daily, equivalent to 4 cups of coffee. This is equivalent to more than 2 litres of average coke beverages. BUT: Pepsi Max contains more caffeine than regular coke, so 2 litres would be too much.

6) Should men stay away from alcohol during fertility treatment like women need to?

No, men do not need to be completely abstinent during fertility treatment, as modest social consumption does not appear to affect either sperm quality or a female partner's chance of getting pregnant. The Danish Fertility Society recommends that men drink less than 14 alcoholic drinks per week. However, the Danish Health Authority has adjusted its recommendation for men to a maximum of 10 drinks per week. It is probably best (for reasons other than fertility) to stick to that recommendation.

7) What are the effects of alcohol and cigarettes on fertility? Is it possible to quit early enough to get pregnant?

Tobacco reduces the chance of pregnancy regardless of how you get pregnant, and it doesn't seem to depend on what kind of tobacco you use. Smoking reduces your chance of getting pregnant via test tube fertility treatments! Smoking also reduces sperm quality. So the message is clear: Stop! As for alcohol, the Danish Fertility Society recommends that women drink less than seven drinks per week and men consume less than 14 drinks per week. The Danish Health Authority has adjusted its recommendation for men to 10 drinks per week for both sexes. You should probably (for reasons in addition to fertility) follow that recommendation.

8) How much exercise is good during treatment, and how high should your heart rate be?

This is a really good question and difficult to answer. Moderate physical activity does not seem to affect the probability of spontaneous pregnancy. Exercise may have a small positive effect for people that are overweight, regardless of the intensity. We know next to nothing about the impact of exercise during fertility treatment. However, it has been shown that the risk of miscarriage early in pregnancy increases 2-4-fold if you do certain types of exercise or if you put more strain on your body than usual. Jogging, ball games, workouts/fitness, and kettle sports increase the risk. Swimming and sedentary physical activity, such as cycling and walking, are fine to continue. Men's exercise does not seem to affect the chances of getting pregnant.

9) Is there a specific diet that impacts fertility?

Yes. Low levels of vitamin D reduce the chances of pregnancy. One of the ways we get vitamin D is through sunlight, so in northern Europe, you need to be particularly careful if you spend a lot of time indoors, or are covered up (even in summer), etc. So if you have low vitamin D levels, you should take a supplement. If necessary, ask your doctor about the dosage. A daily folic acid supplement (0.4 mg per day) reduces the risk of several severe birth defects, and you should start taking it while planning your pregnancy. There is an incredible lack of knowledge about diet and fertility. Many opinions but very little scientific knowledge.

10) Does organic food play a positive role in fertility?

This is a very good question. Most of us would probably like to think that the answer is yes, but the honest answer is that it has not been seriously studied and is, therefore, unknown. Hopefully, future studies can shed light on this matter.

11) Can being slightly overweight (5-8 Kg) cause you to not get pregnant?

Yes, it can. Being overweight reduces your chances of getting pregnant, regardless of the methods used. The main reason is that being overweight increases women's risk of not ovulating. No ovulation, no pregnancy. Unfortunately, being overweight can also affect a wide range of hormones, and this can also affect your chances of getting pregnant.

Similarly, male obesity increases the risk of having too few sperm, reducing pregnancy chances (at least without treatment intervention).

12) What can be done to reduce an elevated DFI?

This is a very good question. First, most public fertility clinics do not measure DFI (DNA Fragmentation Index) in semen samples. Simply because they don't know what's normal and what's not, and so aren't sure what DFI means for pregnancy impact, and because they don't have any helpful treatment anyway. Some suggest reducing alcohol and coffee consumption and stopping smoking, and some recommend using antioxidants. Maybe it works, maybe not, and even if it affects DFI (a little), no one knows if it increases pregnancy chances.

13) Why a BMI limit of 30? Many women with higher BMI have uncomplicated pregnancies and births.

A maximum BMI limit of 30 applies nationally to fertility treatment for women under 35, except for instances where there is low or poor egg reserve. The reasonableness of such a restriction is debatable, as is the specific BMI number the limit is set at. Being overweight reduces the chance of pregnancy by just over 10%. However, the main justification for having BMI limits in fertility treatment is the significantly increased risk of pregnancy and birth complications, including the risk of miscarriage, gestational diabetes, birth defects, pre-eclampsia, stillbirth, blood clots and many others. This balancing act between the desire to create life and the risk of carrying a pregnancy to term.

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