An Estonian study: Overweight men are lowering birth rates

A study conducted at the University of Tartu confirmed that central obesity affects fertility parameters negatively and hence, men should pay attention to their lifestyle.

This article is published in collaboration with Research in Estonia

About 15% of couples in fertile age have experienced fertility problems. Men contribute to 50% of the cases when a couple cannot achieve the desired pregnancy. The proportion of overweight men has tripled in parallel with the increase in fertility problems worldwide.

A doctoral thesis conducted at the University of Tartu Institute of Clinical Medicine confirmed that central obesity affects fertility parameters negatively. To alleviate their fertility problems, men should pay attention to their lifestyle, the study says.

Men’s semen quality has dropped

According to Kristel Ehala-Aleksejev, a doctoral student at the Institute of Clinical Medicine and a physician at Tartu University Hospital Men’s Clinic, men’s semen quality has dropped dramatically over the last century. “Possible reasons for the decline of fertility parameters can be the rapidly changed lifestyle, altered physical activity and eating habits along with other factors. A western lifestyle is conducive to weight gain, which is also a problem among Estonian men,” she said.

A father and a child. The image is illustrative (Pexels).

Ehala-Aleksejev noted that there were studies associating obesity with reduced fertility, but there were other studies denying this. Conflicting results also characterise the relationship between central obesity-related metabolic syndrome and sperm quality. There is, however, an almost unanimous agreement that increased weight has a negative correlation with testosterone levels.

“At an andrology appointment, we often see links between weight and fertility. An important factor with men is the accumulation of fat in the waist region,” Ehala-Aleksejev said. “In addition, obesity as a change in the hormonal balance promotes the development of erection problems, which, in turn, reduces fertility.”

Male fertility is mainly assessed based on semen analysis, but one of the easiest methods for determining fertility potential is the measurement of testicular volume.

Mental health and time for loved ones as important as staying fit

In her doctoral thesis, “The Associations Between Body Composition, Obesity and Obesity-Related Health and Lifestyle Conditions with Male Reproductive Function,” Ehala-Aleksejev looked at provenly fertile men and the male partners of infertile couples.

Comparing the groups showed that a significantly higher prevalence of chubbiness and metabolic syndrome was found among the male partners of infertile couples. Central obesity was associated with a decline in fertility parameters in both groups. According to the doctoral student, the analysis importantly revealed that men with smaller testicles were more affected by an increase in body weight and central obesity.

Ehala-Aleksejev, who is also a nutritional therapist, confirmed that men could do a lot for their health. “They should try to keep physically active, move, and if possible, do sports. They should include more fruit and vegetables and whole-grain products in their diet,” she said. “Smoking and excessive alcohol consumption are notable risk factors of infertility. However, mental health or the ability to alleviate stress and finding time for themselves and their loved ones is no less important.”

Cover: A father and a child. The image is illustrative (Pexels).