classification of pre-eclampsia into early and late pre-eclampsia
Last reviewed 01/2018
The terms early versus late pregnancy is becoming widely accepted as a better indicator of disease significance than the classic terms "mild" or "severe" pre-eclamsia (1).
There is evidence that early onset (before 34 weeks of gestation) is associated with severe pre-eclamsia.
- early onset pre-eclamsia is thought to be due to involvement of the placenta
- abnormal uterine artery Doppler flow
- fetal growth restriction
- adverse maternal and fetal outcomes
- late onset pre-eclampsia (after 34 weeks of gestation) appears to be due to maternal "constitutional" factors, such as body mass index (BMI) and is considered to be associated with a more favorable outcome
Other than the aetiology of the disease, maternal haemodynamics appear to vary according to the time of presentation. A study conducted with 1345 nulliparous patients identified as normotensive with bilateral uterine notching at 20-22 weeks' gestation found out that
- women with early disease had higher total vascular resistance and lower cardiac output
- while late onset women had higher pre-pregnancy BMI, higher cardiac output, and lower total vascular resistance when compared with the early onset and control patients (1)