In a study involving 3,239 women in the US, researchers have found that for every additional centimetre gained around a woman's waistline, the risk of infertility increases by 3 per cent.
The research highlights the significance of maintaining a slim waistline to enhance the prospects of conception. It also indicates that regular exercise might offer protective benefits for fertility.
The participants in the study, averaging 31 years of age, underwent waist circumference measurements.
Approximately one in ten reported facing infertility, defined as unsuccessful attempts at natural conception over a year, The Times reported.
The study revealed a direct correlation between waistline size and fertility challenges.
It was found that women with a waist measurement exceeding 43 inches (109cm) were over twice as likely to experience difficulties conceiving compared to those with waistlines measuring 30 inches (77cm) or less.
After accounting for other influential factors like age, the study estimated a 3 per cent increase in the risk of infertility for every 1cm increase in waist circumference.
However, in women with larger waistlines, engaging in significant exercise was discovered to offset the adverse effects of carrying excess fat.
Published in the journal Plos One, these findings contribute to existing evidence demonstrating a strong correlation between obesity and fertility.
The study suggests that waist size might serve as a more effective indicator of fertility risks linked to obesity compared to metrics like body mass index (BMI).
Stomach fat is particularly concerning as it surrounds vital organs, releasing chemicals that could disrupt hormones and cause inflammation associated with various diseases.
The research reveals that surplus fat influences sex hormone levels and menstrual cycles, contributing to insulin resistance which hinders the body's ability to absorb sugar from the blood, exacerbating hormone imbalances and worsening conditions like polycystic ovary syndrome (PCOS) that contribute to infertility.
Researchers from Huizhou University in China emphasised the significant impact of obesity on fertility and reproductive health.
They said their findings underscored the necessity for effective waist circumference management to mitigate the risk of abdominal obesity and enhance reproductive health.
The study highlights the protective role of moderate recreational activities in reducing infertility risks associated with larger waist circumferences, particularly exceeding 113.5 cm (44 inches).
Previous research has consistently shown that moderate to high levels of physical activity substantially decrease the likelihood of infertility.
In the UK, infertility affects over one in ten couples and can impact both men and women.
A separate study conducted by the University of Western Australia found that adopting a Mediterranean diet was a “straightforward approach” for women undergoing IVF.
The study emphasised the importance for women undergoing fertility treatment to embrace a diet rich in nuts, fish, olive oil, whole grains, and vegetables.
Researchers conducted a comprehensive review of previous studies examining the impact of diet and nutritional supplements on the chances of getting pregnant.
Their findings suggested limited evidence supporting the use of supplements, including traditional Chinese herbs, often promoted for enhancing fertility.
Professor Roger Hart, the study's lead author, highlighted the prevalence of self-medication through nutritional supplements, acquired online or over the counter.
While acknowledging the widespread use, he noted the absence of substantial data on their effectiveness, primarily derived from anecdotal evidence present in online IVF discussion forums.
Hart said there is stronger evidence supporting the adoption of a Mediterranean diet due to its overall health benefits, including reduced inflammation and positive effects on the reproductive system.
He explained that these diets offer high levels of B vitamins, antioxidants, omega-3 polyunsaturated fatty acids, and fibre while maintaining low levels of saturated fat, sugar, and sodium.
The study findings were published in Reproductive Biomedicine Online.
