Obesity is increasing in the population as a whole, and especially in the obstetric population, among whom pregnancy-induced physiological changes impact on those already present due to obesity. In particular, changes in the cardiovascular and respiratory systems during pregnancy further alter the physiological effects and comorbidities of obesity. Obese pregnant women are at increased risk of diabetes, hypertensive disorders of pregnancy, ischaemic heart disease, congenital malformations, operative delivery postpartum infection and thromboembolism. Regional analgesia and anaesthesia is usually preferred but may be challenging. Obese pregnant women appear to have increased morbidity and mortality associated with caesarean delivery and general anaesthesia for caesarean delivery in particular, and more anaesthesia-related complications. This article summarises the physiological and pharmacological implications of obesity and pregnancy and describes the issues surrounding the management of these women for labour and delivery.