THE CHANGING PATTERN OF ECLAMPSIA OVER A 60-YEAR PERIOD

Objective To determine changes in the incidence and pattern of eclamps ia within the same geographical area over a 60-year period. Design A r etrospective, descriptive study of 1259 consecutive women classified, at the time, as having had an eclamptic convulsion between the years 1 931 and 1990. Setting A large city centre teaching hospital and the su rrounding catchment area. Main outcome measures The changes in the inc idence and timing of the convulsion and the outcomes for the mother an d baby. Results Over the study period, the incidence of eclampsia fell by more than 90%, from 74.1/10,000 in the 1930s to 7.2/10,000 in the 1980s. Most of the reduction occurred over the first four decades, wit h little change in the last 20 years. Overall, 44% of the cases of ecl ampsia occurred in the antenatal period, 33% intrapartum and 23% postp artum. Since the biggest decreases were seen in the incidence of anten atal and particularly intrapartum eclampsia, there has been a relative increase in the proportion of eclampsia occurring postpartum. Materna l death from eclampsia occurred in 15.1% of cases between 1931 and 194 0, 13.4% between 1941 and 1950, but fell dramatically to less than or equal to 3.9% after 1950. There has been no maternal death since 1964. Apart from the first decade, postpartum eclampsia was associated with significantly less risk of death to the mother throughout the study p eriod. Perinatal death rate has fallen steadily from 432.6/1000 cases of eclampsia between 1931 and 1940 over the first three decades, to 16 8.7/1000 between 1961 and 1970. There has been little change since, al though a lower proportion of neonatal deaths occurred as stillbirths. Conclusions We found a significant reduction in both the incidence of eclampsia and associated morbidity in this population over the last 60 years. This has occurred in association with the introduction of the National Health Service, widespread antenatal care for all and a gener al improvement in health and welfare. Any further reduction in the inc idence in the UK may be difficult to achieve. Since the incidence of e clampsia is now low, efforts should perhaps be directed at minimising the morbidity associated with severe pre-eclampsia rather than prevent ion of convulsions.