Table 1.

Hypertensive disorders of pregnancy: definitions and associated features

Hypertensive Disorder	Definition of hypertension	Associated Features
Chronic hypertension	Onset before pregnancy or before 20 weeks’ gestation:  −  ≥ 140 mmHg SBP or  −  ≥ 90 mmHg DBP	− Mainly due to essential hypertension  − 24-h ambulatory BP monitoring assists the exclusion of white-coat hypertension  − Risk factor for preeclampsia, maternal CVD and FGR
Gestational hypertension	New onset at or after 20 weeks’ gestation:  −  ≥ 140 mmHg SBP or  −  ≥ 90 mmHg DBP	− May be transient in nature, arising and settling in the 2nd-3rd trimester  − 25% will progress to preeclampsia  − Return to normal BP postpartum with no antenatal proteinuria or maternal end-organ dysfunction  − Increased future risk of maternal CVD
Preeclampsia	New onset at or after 20 weeks’ gestation with end-organ dysfunction:  −  ≥ 140 mm Hg SBP or  −  ≥ 90 mm Hg DBP	New onset of ≥ 1:  − Proteinuria  − Acute Kidney Injury  − Elevated liver transaminases  − Neurological complications  − Thrombocytopenia  − Uteroplacental dysfunction  − FGR  − HELLP syndrome (haemolysis, elevated liver enzymes, thrombocytopaenia)
Eclampsia	New onset of antenatal, intrapartum or postpartum tonic–clonic, focal, or multifocal seizures without other causative conditions	Often preceded by:  − Severe and persistent occipital or frontal headaches  − Blurred vision  − Photophobia  − Altered mental status

Abbreviations: BP Blood pressure, CVD Cardiovascular disease, DBP Diastolic blood pressure, FGR Fetal growth restriction, mmHg millimetres of mercury, SBP Systolic blood pressure