Research to Reader: fertility science
1. Exercise Can Help Improve Overall Fertility
Being underweight may impair hormones that influence ovulation, just as being overweight and not engaging in sufficient activity is also associated with disturbances of the menstrual cycle, and therefore increasing the risk of infertility. The good news is that the right exercise prescription can restore balance to the menstrual cycle.
Many studies have been conducted that support how exercise can improve overall fertility. In one, a six-month exercise intervention in overweight women with a prolonged history of anovulation (with and without polycystic ovary syndrome) restored ovulation in 89% of women and 77% became pregnant. Because exercise had restored regular ovulation, 27% of these pregnancies happened spontaneously without fertility treatment.
Studies have also shown that women with a high body mass index (30+) that undertake regular exercise before in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) have a 3 fold higher chance of getting pregnant and having a baby than those who do not. A 300% increase - that is absolutely huge! This increase in the chance of becoming pregnant is realized even without a significant reduction in body weight. For women experiencing infertility with a high body mass index (BMI), exercise should always be considered as your very first option, not a last resort!
2. Exercise Can Impact Sperm Quality
Male factor infertility accounts for ~20% of IVF/ICSI cycles undertaken. While there are many reasons for male infertility, there is a 50% greater chance of reductions in fertility in overweight males. Male factor infertility is associated with increased levels of inflammation and oxidative stress that can damage sperm, causing DNA fragmentation. Male factors, such as increased oxidative stress, are also implicated in recurrent pregnancy loss (RPL).
Exercise has been shown to improve sperm quality and DNA damage by reducing markers of inflammation and oxidative stress. Research also shows that exercise can combat the negative effects of a bad diet for sperm, improving sperm quality by 68%. Importantly, moderate intensity exercise is superior to high-intensity interval training for improving sperm health so you need to get the exercise prescription right. For highly trained athletes, regular, high-intensity exercise with minimal recovery between sessions may actually reduce sperm quality.
If you are male and your preferred mode of exercise is cycling there is also evidence to suggest that you may need to back off time spent on the bike and swap this for another aerobic activity. Cycling for more than five hours a week is associated with a 92% chance of low sperm concentration.
If you are a gym junkie then keep training at moderate levels and avoid the use of supplements which may be contaminated with steroid-like substances. It goes without saying, avoid the use of anabolic steroids too. After two years of anabolic steroid use, 80% of bodybuilders (average age 27 years) had testicular atrophy, 24% reduction in sperm volume, 32% reduction in sperm motility, and a 62% reduction in sperm fertility index – not great for baby making.
Even if male factor fertility issues are not the primary reason you are undergoing IVF, ensuring your sperm are in tip-top shape will help you to maximize your chances. If you have not exercised regularly before and are planning to undergo IVF, exercise will benefit your sperm health.
3. Have PCOS? Exercise Should be Your First Line of Treatment
If you have polycystic ovary syndrome (PCOS) and as a result suffer from irregular ovulation or the total absence of menstrual periods, exercise should be your first line of treatment. Evidence shows that differences in the expression of progesterone receptors in the endometrium of women with PCOS could impact upon embryo implantation. The right exercise prescription can restore balance to the menstrual cycle, and in particular women with PCOS can realize benefits of improved blood glucose control and insulin resistance, even without weight loss. Exercise can also restore progesterone receptors in the endometrium, which can benefit embryo implantation. It’s no wonder that Medical Research Guidelines state that exercise should be first line therapy for all women with PCOS.
4. Ban the Bed Rest After Embryo Transfer
Women seem to be frequently told that they should be on complete bed rest for two days after their embryo transfer as part of their in vitro fertilization (IVF) cycle. While it is not the time to run a marathon, everything we know about the negative effects of bed rest for physiology and your mental state suggests that this would be detrimental.
A systematic review (scientific analysis of all of the literature on the topic) exploring the effects of bed rest after embryo transfer and the outcome of IVF/ICSI suggests that bed rest is not good. The review included studies involving autologous transfers (women’s own eggs) and varied fertility issues such as oligomenorrhea (infrequent menstrual periods), endometriosis and male factor infertility. In one study included in the review, the patients were even catheterized so they didn’t have to get up and go to the toilet! Who has two days to hang around in bed? Prolonged bed rest (24 hours) was found to be associated with lower rates of clinical pregnancy. Women who rested in bed were 40% less likely to have a Big Fat Positive (BFP). So while it is not the time to run a marathon, light to moderate aerobic exercise and certain strength training exercise are suitable for the post-transfer period and during the two week wait (2WW).
5. Infertility is Tough, so Move to Improve Your Mood
The stress that comes with infertility and undergoing assisted reproductive treatment (ART) can be equivalent to that of someone dealing with cancer or heart disease. Depression, anxiety, and stress are very common in those undergoing treatment. There are many reasons for this stress and these can relate to a sense of a loss of hope, the stress of constant appointments and invasive procedures such as the injections required and egg retrieval procedures, and the stress that follows an embryo transfer and waiting for a pregnancy test. Oh, and let’s not forget to mention the financial stress, relationship stress, the side effects from all the drugs, the stress of treatment outcome - you get the picture. Ironically, while the fertility treatment you are undergoing to get pregnant increases stress, stress is not conducive to a positive outcome for assisted reproductive treatment. Women with prolonged elevated levels of the stress hormone cortisol (measured from hair samples which provide a picture of exposure to stress over time) prior to treatment were 27% less likely to get pregnant.
The right exercise prescription can increase your resilience, reduce depression and anxiety, help manage your mood and help you sleep instead of worrying about all the things that could keep you up at night. All of these benefits are great for you – but also for your assisted reproductive treatment. Exercise has been shown to increase your ability to bounce back from a stressful situation and to limit how much stress you experience. This is essential for riding the roller coaster of fertility treatments. Exercise is one 'tool' in your resilience coping tool box to handle the stresses of all the poking and prodding and waiting.
6. Prepare Your Body for IVF and Beyond
Prepare your body, not just for conception but for pregnancy and beyond. Your lifestyle choices now will not only influence the quality of your eggs or sperm, but they can leave a legacy influencing the health of your offspring. At a minimum, a three-month investment in making positive lifestyle changes that include exercising right could save you treatment cycles (which translates to saving your emotional sanity and money).
If you conceive, this is just the start of a very long journey where your health has a direct influence on not only the health of your pregnancy but your child’s health. Exercise during pregnancy reduces gestational diabetes, low back pain assists with gestational weight control and reduces the need for a caesarean section (C-section). Exercise during pregnancy also boosts newborn brain development so start planning not just for the timing of your trigger shots but for a healthy pregnancy and beyond.
7. How Much Exercise is Too Much During IVF?
The blanket advice offered to women undergoing IVF is often to ‘reduce exercise’ during treatment cycles but without knowing how much someone is doing and if the exercise intensity and frequency are appropriate, this blanket advice could actually reduce the chance of IVF success for some couples.
For women that have a low body mass index (<20) and low body fat levels, it is important to get the balance of moderate and vigorous exercise right and ensure you are getting enough nutrients for the amount of activity you are doing. For women and men that have never exercised regularly, a gradual progression in your exercise prescription is most beneficial. It is imperative that your body composition and current activity is considered to prescribe the right amount and intensity of exercise to optimize your fertility treatment.
8. Timing is Everything with Exercise and IVF
Different stages of an IVF treatment cycle require different exercise prescriptions. For men, the exercise you do in preparation for providing a sperm sample may be different to the exercise you do in the post-collection period. For women, your exercise prescription will differ between pre-treatment, stimulation, the period between egg collection and transfer day, and the seemingly forever two week wait. There will also be differences in your exercise prescription for frozen treatment cycles.
9. Get Strong and Build Muscle to Improve Fertility
Body composition (the balance between muscle mass and body fat) influences the chance of spontaneous conception and the outcome of IVF/ICSI so maintaining optimal body composition is a great way to improve your reproductive health. Strength training is the best way to maintain muscle mass, boost your metabolism, and reduce body fat. And you can do this all without having to set foot in a gym! Strength training will not only improve sleep but is a natural antidepressant that reduces inflammation – one of the hallmarks of conditions such as PCOS, endometriosis, and male infertility.
10. How Do You Know What Exercise is Safe During IVF?
Just as you want a specialist extracting your eggs or handling your sperm sample, make sure you see an expert for exercise guidance. An Exercise Physiologist can help to create the right program to improve your chance of success needs to be based on your current health and activity levels, the cause of infertility and in particular your stage of fertility treatment. The scientific evidence is clear that the correct exercise prescription can improve your chance of success. Your program from The IVF Project will provide you with the right prescription!