Identifying genetic determinants of fertility

Professor Melinda Mills co-authored ground-breaking research published in Nature Human Behaviour, the largest study to date which identifies genetic determinants. The findings demonstrate that fertility is affected by diverse biological mechanisms, which contribute to variations in fertility, and directly affect puberty timing, sex hormone levels (such as testosterone), endometriosis and age at menopause. There were also links to behaviours such as risk taking. The study team also identified that the human genome has been influenced by natural selection for thousands of years and continues to affect fertility today.

The research team used data from 785,604 individuals of European ancestry, including individuals in the UK Biobank study, to identify 43 regions of the genome containing genetic variants associated with reproductive success, defined as the number of children ever born to an individual.

The findings contribute to understanding changes in human reproduction over longer periods of time, reproductive biology and potential links to infertility. The study has also highlighted new biology that could help identify novel therapeutic targets for reproductive diseases, and help to better understand the biological mechanisms that link reproductive health to broader health outcomes in men and women.

Professor Mills also co-authored research which has revealed a significant association between 74 earlylife diseases and the likelihood of remaining childless throughout one’s life, with 33 of these diseases prevalent in both women and men.

Published in Nature Human Behaviour, the study examined the link between 414 early-life diseases and lifetime childlessness in over 2.5 million individuals born in Finland and Sweden. In many Western European and East Asian countries, up to 15-20% of individuals born around 1970 are now childless. Although multiple social, economic and individual preferences have been studied, there has been limited research examining the contribution of different diseases to being childless over a lifetime, particularly those diseases with onset prior to the peak reproductive age.

This study contributes to a better understanding of how disease contributes to involuntary childlessness and the need for improved public health interventions which address early-life diseases among both men and women.

Further reading

Genome-wide analysis identifies genetic effects on reproductive success and ongoing natural selection at the FADS locus (Nature Human Behaviour)

New study on human fertility (LCDS news)

Video on new study on human fertility (LCDS)

Evidence from Finland and Sweden on the relationship between early-life diseases and lifetime childlessness in men and women (Nature Human Behaviour)

The relationship between early-life diseases and lifetime childlessness in Finland and Sweden (LCDS news)

Evidence from Finland and Sweden on the relationship between early-life diseases and lifetime childlessness in men and women (Interactive online dashboard)