The first step in treating infertility is to identify the lifestyle and harmful factors that contribute to infertility. A person’s fertility can be altered by factors such as marijuana, antidepressants, weight, dietary habits, intense exercise, stress, sexual activity directed at the day of ovulation, and psychological stress. Diagnosis and early treatment of these harmful factors and lifestyles can lead to increased natural fertility and reduce the need for assisted reproductive medicine.
Impact of lifestyle on fertility
1. Smoking
Tobacco: In women, a meta-analysis by Augood et al. showed that smoking delayed female fertility by more than one year. This is dose- and time-dependent on exposure. There is a dual risk of infertility and reduced ovarian reserve and can lead to a reduction in anti-mullerian hormone (AMH) levels. Women in the smoking group often experience shortened irregular periods, greater ovarian insufficiency and dysmenorrhea.
In men, maternal smoking increases the risk of bilateral cryptorchidism in infants, and male infants born to women who smoke more than 10 cigarettes per day have a 20% reduction in total sperm count and reduced testicular volume in adulthood. Smoking in adults affects erectile function and causes chromosomal aberrations in sperm, leading to an increased number of miscarriages. Although the direct effects of tobacco are not well understood, quitting for 3 months does improve sperm quality.
Smoking in both men and women reduces the chance of successful assisted reproductive technology (ART) by more than 40%, and intracytoplasmic sperm injection (ICSI) failure rates are three times higher in smokers than in nonsmokers. In addition, women who have smoked for more than 5 years at the time of IVF/ICSI have a four-fold higher risk of not conceiving. Quitting smoking is necessary, at least when planning a pregnancy, to stop the adverse effects on ovarian function and to increase the chances of a natural pregnancy.
Marijuana: In men, smoking marijuana several times a week for up to 5 years can cause a reduction in sperm volume and count, altered sperm morphology and viability, as well as overactive sperm and reduced fertilization capacity. Compared to tobacco, marijuana is removed more slowly and the harmful effects are more pronounced. Marijuana decreases testosterone (T) production, and more than one-third of men who smoke marijuana develop oligospermia. Marijuana causes decreased libido, male breast development and erectile dysfunction.
Marijuana use can lead to menstrual cycle disruption in women, a reduction in the number of oocytes harvested in in vitro fertilization, and a higher risk of preterm birth. Although cohort studies are required, current research indicates that marijuana has adverse effects on fertility.
2. Alcohol
Available information on the potential effects of alcohol is less clear, particularly because of the diversity of alcohol and the difficulty of determining frequency thresholds for alcohol consumption. The risk threshold for alcohol to affect male infertility appears to be 30 g/day. Excessive alcohol consumption is considered to be a risk factor for male infertility.
It has been shown that ethanol has an effect on the hypothalamus, blocking the secretion of GnRH (gonadotropin-releasing hormone) and the binding of GnRH precursors, which activate gonadotropin-releasing hormone. This process leads to a decrease in LH and FSH and subsequent impairment of spermatogenesis.
Recently, Jensen et al. found that the amount of free testosterone in the serum of couples in the week prior to IVF increased significantly with the number of alcohol drinks. This study suggests that even habitual alcohol consumption of more than 5 units per week can have a detrimental effect on semen quality. The most significant effects were seen primarily in men who drank more than 25 units of alcohol per week.
For women, moderate wine consumption (more than two glasses per day) can shorten the waiting time for conception. Research on the ART cycle is quite scarce. Wdowiak et al. showed that alcohol consumption may cause embryonic dysplasia. More grade B embryos were derived from the oocytes of women who drank alcohol than from grade A embryos. In this study, 42.59% of the women drank alcohol. Women of childbearing age should avoid alcohol to protect their fertility.
3. Medication
Many medications are associated with changes in fertility. Amory and Swerdloff recently cited dutasteride and finasteride for hair loss as factors affecting male infertility. The generalized literature on the effects of drugs and fertility remains inadequate.
4. Caffeine
The mechanism of action of caffeine to affect fertility is unclear. In men who drank coffee, semen volume was slightly higher, but the concentration was lower. The findings show that sperm motility, morphology, DNA fragmentation and chromatin depolymerization are not related to caffeine.
Live birth rates were lower in babies born to IVF patients who consumed coffee. Caffeine is a phosphodiesterase inhibitor. This phosphodiesterase inhibitor (ORG9935) inhibits the maturation of oocytes in gonadotropin-stimulated macaques, and Pauli et al. speculated that reducing caffeine intake prior to IVF would reduce the number of immature oocytes recovered. Many lifestyle habits have been associated with infertility. Clear evidence of caffeine intake alone in male and female patients has not been found.
5. Cell phone use
The literature suggests that cell phone use can alter sperm parameters, particularly motility and morphology, and increase oxidative stress. Furthermore, these abnormalities seem to be directly linked to the duration of cell phone use. However, conducting a prospective randomized controlled study seems difficult considering the widespread use of computers and cell phones. The use of new technologies should be evaluated over the next 20 years.
Role of environment, occupational pollutants and oxidative stress
1. Environmental exposure
A review of the literature suggests that occupational exposure to lead and cadmium, as well as exposure to pesticides and solvents, may have some effect on infertility. In contrast, further confirmation is needed as to whether solvent and pesticide exposure affects fertility. A meta-analysis showed that an increase in hypospadias was associated with parents being farmers.
Although more in-depth studies are needed, Garlantezec and Multigner’s report highlights that certain occupations (farmers, foundry workers, horticulture, armed forces, hairdressers, workers in shoe factories and food processing plants, cleaners, nurses) or pesticide and solvent exposure are associated with fertility problems in some couples. It should be noted that exposure to hazards is often accompanied by high levels of stress, which also increases the harmful nature of the workplace. Cohort studies of biomarker testing will help to raise awareness of occupational exposures.
2. Stress
The effects of stress on infertility remain controversial. This is mainly because, despite advances in medicine, the high incidence of infertility remains unexplained.
Lynch et al. showed an association between salivary stress biomarkers and the timing of pregnancy in infertility. Stress can be measured by an increase in salivary α-amylase, which is associated with lower fertility in women.
However, smoking is one of the most common environmental exposures that cause oxidative stress. In this study, smoking the day before oocyte collection was shown to have no effect on alpha-amylase levels. It seems wise to consider stress as a potential factor for infertility, and it provides further evidence for adverse effects due to stress.
Discussion
The search for lifestyle and deleterious factors of infertility is the first step in the treatment of infertility. There is a significant difference in the accumulation of factors in men and women. hassan and Killick showed that the accumulation of deleterious factors leads to a longer time to conception. Infertility stress is present in one in two (53%) women; in men, it is not as pronounced.
Prospective studies have shown that many factors are detrimental to fertility in both men and women. But these cumulative factors apply not only to individuals, but also to couples. In fact, the study’s analysis suggests that female factors such as smoking, marijuana, alcohol, sleep disorders, family stress, and stress associated with infertility are likely to be present with men who live with the same factors.
Conclusion
Along with the diagnosis of the etiology of infertility, the treatment of infertile couples requires screening for factors that influence the environment and lifestyle of fertility. Such an approach is necessary for couples with fertility difficulties but without infertility disorders. This study highlights the need to screen and correct harmful factors and unfavorable lifestyles in infertility patients prior to any medically assisted fertility treatment. Comprehensive treatment regarding the determinants of infertility should be offered to the patient during early screening.
Treatment of infertility is based on weight loss, reduction of harmful factors, stress management, and coping with harmful factors at work. Harmful factors (especially smoking) should be reduced 3-6 months before the patient starts with any assisted reproduction techniques. Detection and correction of poor lifestyle and harmful factors are fundamental to improve spontaneous fertility and ART outcomes. Also, information exchange and collaboration between health care authorities, infertile couples, doctors and nurses is necessary to improve fertility of couples.