Male belly fat reduces a man’s chance of becoming a father by almost half, according to a new study.
The research, which was presented at the The European Society of Human Reproduction and Embryology (ESHRE) conference last month, found that every 5cm increase in a man’s middle section, reduced his partner’s chances of having a baby by 9 per cent at each IVF attempt.
As part of the study, researchers tracked 179 couples undergoing IVF during January 2019 at Massachusetts General Hospital Fertility Center. Men’s and women’s height, weight and waist circumference were all measured.
“These results suggest that central obesity may be an independent risk factor for male factor infertility,” the researchers, led by Harvard Public Health concluded.
According to the team, belly fat produces a chemical that turns testosterone into the female sex hormone oestrogen.
Having a ‘pot belly’ was especially problematic, with researchers claiming it can reduce a man’s chances of producing offspring by 46 per cent.
Dr Fleur Cattrall, fertility specialist at Melbourne IVF, tells Essential Baby that while we already knew a man’s weight could negatively affect sperm quality, “This study is important as it shows that the higher the man’s waist circumference, the lower the chance of their partner becoming pregnant with IVF.”
According to Dr Cattrall, often the focus is on the female partner’s pre-pregnancy health. In reality, however, “conception is a team effort”.
“This study shows the importance of men optimising their health, particularly their weight prior to commencing IVF treatment to increase the chances of success,” Dr Cattrall says.
“Sperm production actually takes about three months, so I like to remind men that the sperm they are producing today was actually made six weeks ago.”
Dr Cattrall notes that this encourages men to plan ahead, “to limit their alcohol intake, boost their diet with fresh fruit and vegetables and to aim for optimal weight range as this can help develop healthy sperm.”
“Many couples are working from home, spending more time indoors so the potential to overeat is high,” Dr Cattrall says.
Another study shows that men who reduce their abdominal Fat us associated with an improvement of sperm quality and pregnancy. The impact of being overweight amongst men of reproductive-age may affect fertility. Belly fat, more than body mass index, is an indicator of higher metabolic risk, which seems to be involved in decreasing sperm quality.
The study aims to assess the relationship between abdominal fat and sperm DNA fragmentation and the effect of abdominal fat loss, among 6 men in subfertile couples.
Sperm DNA fragmentation, abdominal fat and metabolic and hormonal profiles were measured in the 6 men before and after dietary advices. Seminal oxidative stress and antioxidant markers were determined.
After several months of a lifestyle program, all 6 men lost abdominal fat (patient 1: loss of 3 points of abdominal fat, patient 2: loss of 3 points, patient 3: loss of 2 points, patient 4: loss of 1 point, patient 5: loss of 4 points and patient 6: loss of 13 points).
At the same time, their rate of sperm DNA fragmentation decreased: 9.5% vs 31%, 24% vs 43%, 18% vs 47%, 26.3% vs 66%, 25.4% vs 35% and 1.7% vs 25%. Also, an improvement in both metabolic (significant decrease in triglycerides and total cholesterol; p = 0.0139) and hormonal (significant increase in testosterone/oestradiol ratio; p = 0.0139) blood profiles was observed after following the lifestyle program. In seminal plasma, the amount of SOD2 has significantly increased (p = 0.0139) while in parallel carbonylated proteins have decreased.
Furthermore, all spouses got pregnant. All pregnancies were brought to term.