Preeclampsia in twins: How different from singletons

Hypertensive disorders of pregnancy contribute significantly to maternal and perinatal mortality and morbidity. Twin pregnancies which already carry an increased risk to mothers and fetuses, are affected in more significant numbers, earlier gestations and more severely by preeclampsia. This narrative review assesses the current state of research on maternal haemodynamics in twin pregnancy and the specific changes in those affected by preeclampsia. We assessed current literature focusing on maternal haemodynamics, angiogenic markers and screening models in twin versus singleton pregnancies. Relevant literature was identified through a search of electronic databases using keywords such as "twin pregnancy", "preeclampsia" and "maternal haemodynamics". Studies were included based on their relevance to cardiovascular adaptation and clinical outcomes in twin pregnancy. We highlight the unique challenges of diagnosing and managing preeclampsia in twin pregnancies compared to singleton pregnancies.