Fig. 4.
Four credible ways in which maternal genetic variants can be related to an offspring exposure (XO) and offspring outcome (YO). Gm is a set of maternal genetic variants GO is a set of offspring genetic variants. Blue crosses indicate the act of conditioning on maternal or offspring genotype, blocking the association between maternal and offspring variables. Dotted paths show paths in which the maternal genotype can be related to offspring phenotype that are not to do with the intrauterine environment (adapted from Evans et al. [29] Moen et al. [95] and Warrington et al. [14])