Researchers have conducted a review into how genetic variations can explain differences in when we have children, the timing of menopause, and how long we live.
The review looked male and female genetic discoveries, identifying 159 genetic studies and 37 key genes that are linked to reproductive traits such as age at first childbirth, menopause timing, and hormones such as follicle-stimulating hormone (FSH) and testosterone.
According to the researchers from Oxford Population Health and the University of Iceland, these findings suggest that genetic factors play a significant role in fertility and health, revealing further connections between reproductive genes and rare genetic disorders.
Senior lead author Professor Melinda Mills, said: “As more people delay parenthood to later ages, it is important to understand the genetic factors underpinning an individual’s reproductive health and fertility window.
“Our study brings together research on the genetics of reproduction to reveal common genes across traits and insights beyond fertility that are inherently linked to health, body mass index (BMI) and obesity, hormone sensitive cancers, and even psychiatric and behavioural traits.”
First author Dr Stefanía Benónísdóttir, said “By consolidating this research, we offer a clearer picture of how genetic factors shape reproductive health. This is essential for advancing healthcare, especially when it comes to infertility and reproductive ageing.”
The further found that reproductive genes such as ESR1 are linked to reproductive traits as well as cancer risk. For example, starting puberty earlier or experiencing later menopause may increase the risk of hormone-sensitive cancers like breast cancer, but these same traits are associated with a longer lifespan.
The FTO (fat mass and obesity associated) gene – previously found to have strong associations with BMI, obesity risk and type 2 diabetes – was also linked to multiple different reproductive traits. Understanding these genetic links is critical as more people choose to delay having children, making reproductive health and ageing even more intertwined.
For men, the review found that genes such as DNAH2 play a role in testosterone levels and sperm function.
Co-author Vincent Straub, said: “Male reproductive health is critical to overall fertility but often under-researched. By exploring the genetics of male infertility, we can uncover new insights and potential treatments for those struggling with reproductive challenges.”