Maternal obesity is a growing epidemic associated with negative outcomes for both the mother and the infant, including pre-eclampsia, gestational diabetes (GDM), and infants born overweight. Emerging evidence also suggests that pre-pregnancy maternal obesity has a detrimental effect on child neurodevelopment, affecting both cognition and behavioural development. This phenomenon is likely a direct result of a suboptimal environment in the womb. However, obesity is also associated with the activation of the immune system, which may further trigger adverse consequences in the developing fetal brain. A second potential pathway through which maternal obesity may act is through changes in the fetal steroid or hormonal environment. Obese women have increased levels of leptin which have been correlated to higher fetal leptin levels. Leptin is believed to have a role in fetal brain development, specifically behavioural regulation. Though studies have begun examining the role of maternal pre-pregnancy obesity on childhood neurodevelopment, only one study has considered the role of inflammation or hormones as potential biological mechanisms of action. Nevertheless, their role remains unclear.