A complication of pregnancy (see PREGNANCY AND LABOUR), of unknown cause, which in severe cases may proceed to ECLAMPSIA. It is characterised by HYPERTENSION, renal impairment and OEDEMA, often with PROTEINURIA and disseminated intravascular coagulation. It usually occurs in the second half of pregnancy – mild cases (without proteinuria) occurring in about 10 per cent of pregnancies, severe cases in about 2 per cent. Predisposing factors include a first pregnancy, or pregnancy by a new partner; a family history of pre-eclampsia, hypertension, or other cardiovascular disorders; and pre-existing hypertension or DIABETES MELLITUS. Increased incidence with lower socio-economic class may be linked to diet or to failure to attend for antenatal care. Although less common in smokers, fetal outlook is worse. Multiple pregnancy and HYDATIDIFORM MOLE, together with hydrops fetalis (see HAEMOLYTIC DISEASE OF THE NEWBORN), predispose to early and severe pre-eclampsia.
Severe pre-eclampsia is an emergency, and urgent admission to hospital should be arranged. Treatment should be given to control the hypertension; the fetal heart rate carefully monitored; and in very severe cases urgent CAESAREAN SECTION may be necessary.