About the speaker
Robyn Wootton is a research associate in mental health at the University of Bristol. She was granted the Gro Harlem Brundtland Visiting Scholarship for the Centre for Fertility and Health and has been visiting the Centre since November 2018. She graduated from the University of Warwick in 2014 with a BSc (with First Class Honours) in Psychology. Her PhD at the University of Bristol investigated the genetic aetiology of subjective wellbeing and other positive mental health outcomes including optimism, gratitude and trust. Robyns current research projects apply the method of Mendelian Randomisation to understanding the associations between health behaviours and mental health. She is exploring the role of BMI, diet and smoking with relation to each other and to subjective wellbeing.
Many health behaviours, including substance use and obesity, are associated with reduced fertility. However, evolutionary theory would suggest that risky health behaviours represent a fast life history strategy, and should therefore be associated with having a greater number of children. We used Mendelian randomisation to investigate causal effects of health behaviours (smoking, alcohol, caffeine and obesity) on: 1) fertility (e.g. length of time to conceive), and 2) reproductive success (e.g. number of children) in the Norwegian Mother and Child Cohort Study (MoBa). We found strong observational evidence for an association between BMI and reduced fertility. However, this was not supported by the MR results suggesting that the association might be due to residual confounding from lifestyle factors. Furthermore, we found evidence to suggest that liability for smoking initiation predicts a younger age at first birth and a greater number of children.