As the obesity pandemic continues in the United States, obesity in pregnancy has become an area of interest. Many studies focus on women with body mass index (BMI) ⩾ 30 kg m(-2). Unfortunately, the prevalence of patients with BMI ⩾ 50 kg m(-2) is rapidly increasing, and there are few studies specifically looking at pregnant women in this extreme category. The purpose of this article is to highlight some of the challenges faced and review the literature available to help guide obstetricians who might encounter such patients.