Rheumatic heart disease (RHD) is the most serious complication of acute rheumatic fever (ARF) and is a significant cause of mortality and morbidity in New Zealand. Rates of ARF in Maori and Pacific Island peoples are among the highest in the world - with Maori 22 times more likely, and Pacific Island peoples 75 times more likely, than NZ Europeans to have RHD. The increased cardiac work in pregnancy means that pregnant women with RHD are at greater risk of developing severe maternal, and therefore fetal, complications. While the rate of ARF is reported in NZ, the rates and outcomes in pregnant women in New Zealand is unknown. This prospective, descriptive study will identify the prevalence, geographic distribution, severity and management of RHD in pregnancy throughout NZ. The evidence-base will be used to identify opportunities for improving clinical care, and maternal and perinatal outcomes for these women.