This study aimed to measure the incidence of eclampsia in the United Kingdom, document its associated morbidity and mortality, and identify risk factors. A prospective, descriptive study was conducted in 1992, involving all 279 hospitals with consultant obstetric units. Obstetricians and midwives notified 582 possible cases, of which 383 were confirmed as eclampsia. The national incidence was 4.9 per 10,000 maternities (95% CI 4.5 to 5.4). Most convulsions occurred despite antenatal care and within one week of the last medical visit. Preterm and antenatal eclampsia were particularly severe, with higher rates of maternal complications and neonatal mortality. The maternal case fatality rate was 1.8%, and 35% of women had at least one major complication. The study concluded that eclampsia is a significant complication, affecting nearly one in 2,000 maternities, and is associated with high maternal and perinatal morbidity and mortality. Preterm and antepartum eclampsia were found to be particularly severe. The findings highlight the need for improved screening and management to reduce the impact of eclampsia.This study aimed to measure the incidence of eclampsia in the United Kingdom, document its associated morbidity and mortality, and identify risk factors. A prospective, descriptive study was conducted in 1992, involving all 279 hospitals with consultant obstetric units. Obstetricians and midwives notified 582 possible cases, of which 383 were confirmed as eclampsia. The national incidence was 4.9 per 10,000 maternities (95% CI 4.5 to 5.4). Most convulsions occurred despite antenatal care and within one week of the last medical visit. Preterm and antenatal eclampsia were particularly severe, with higher rates of maternal complications and neonatal mortality. The maternal case fatality rate was 1.8%, and 35% of women had at least one major complication. The study concluded that eclampsia is a significant complication, affecting nearly one in 2,000 maternities, and is associated with high maternal and perinatal morbidity and mortality. Preterm and antepartum eclampsia were found to be particularly severe. The findings highlight the need for improved screening and management to reduce the impact of eclampsia.