Pre-eclampsia: Praxis and application

Pre-eclampsia is a pregnancy-specific disorder, characterised by hypertension and multi-organ system involvement, that occurs in approximately 2-8% of pregnancies worldwide. Hypertensive disorders, including pre-eclampsia, remain one of the leading causes of maternal morbidity and a great contributor of maternal and perinatal mortality. Globally, approximately ten million women develop pre-eclampsia each year, and an estimated 76 000 pregnant women die annually from pre-eclampsia and related hypertensive disorders. There is also a high relative risk of fetal death in pregnancies diagnosed with pre-eclampsia. Despite ongoing research, the pathogenesis of pre-eclampsia remains unclear. This article will focus on the diagnosis, risk factors and aetiology of pre-eclampsia, while attempting to outline the collaborative management options for treatment and prevention.

Traditionally, pre-eclampsia is diagnosed as a new onset of hypertension and proteinuria after 20 weeks of gestation (Chaiworapongsa et al, 2014a). Hypertension in pregnancy is classified as a systolic blood pressure greater than or equal to 140 mmHg, and a diastolic blood pressure greater than or equal to 90 mmHg on two separate measurements taken 4–6 hours apart (Tannetta and Sargent, 2013). A diagnosis of proteinuria in pregnancy is when the total weight of protein in urine is greater than or equal to 300 mg in a 24-hour period (Chaiworapongsa et al, 2014b). Although hypertension is an essential element in the diagnosis of pre-eclampsia, the presence of proteinuria is not critical, and as a result, pre-eclampsia can be separated into non-proteinuric or proteinuric pre-eclampsia (Shennan, 2016). Non-proteinuric pre-eclampsia involves new onset of hypertension and the existence of systemic disease, which may include liver involvement, renal insufficiency, neurological and haematological complications, fetal growth restriction and uteroplacental dysfunction (Mol et al, 2016). The rationale for the exclusion of proteinuria in the diagnosis of pre-eclampsia is that pre-eclampsia may be evident before renal involvement has occurred (Chaiworapongsa et al, 2014a).