Using Mendelian Randomization to investigate possible causal effects of maternal environmental exposures during pregnancy on offspring short and long-term outcomes

Randomized controlled trials – the golden standard for studying cause and effect – if often difficult to perform during pregnancy, due to ethical considerations. Studying the effect of environmental exposures during pregnancy on offspring outcomes is therefore often left to observational studies, which could be confounded by social, environmental and behavioral factors. Mendelian randomization, which uses genetic variants related to an exposure of interest as instruments for that exposure is less prone to these biases. However, investigating the effect of maternal environmental exposures on offspring outcomes, such as for example birthweight, is more complicated, because we have both maternal and offspring genetics (which are correlated, r ≈ 0.5) influencing the outcome of interest. In this talk I will discuss methods developed to perform maternal Mendelian randomization analysis on offspring outcomes properly accounting for offspring genetics, and  how we can use these methods to answer questions related to the causal effect of environmental exposures during pregnancy on offspring outcomes.

Dr Gunn-Helen Moen was awarded her PhD on the "Genetic and environmental etiology of glucose metabolism and cardiometabolic traits during pregnancy and in later life" in 2019 from the Faculty of Medicine at the University of Oslo. After finishing her PhD, she was awarded a Mobility/Marie Sklodowska-Curie Fellowship from the Research Council of Norway and as part of that fellowship spent two years as a visiting academic at the University of Queensland. She is currently an ARC DECRA fellow at IMB. Her research focus is on using Mendelian randomization to investigate the possible causal effects of maternal environmental exposures during pregnancy on offspring outcomes.