Table 1.

Comparison of definitions among different societies

CategoryACOG (89)SOGC (90)RCOG (www.nice.org.uk/guidance/cg107)SOMANZ (91)ISSHP (92)
Chronic HTN/essential HTNsBP≥140 mmHg and/or dBP≥90 mmHg known to predate conception or detected before 20 wk of gestation, with no underlying causesBP≥140 mmHg and/or dBP≥90 mmHg that develops either prepregnancy or at <20+0 wk of gestationHTN that is present at the booking visit or before 20 wk or if the woman is already taking antihypertensive medication when referred to maternity servicessBP≥140 mmHg and/or dBP≥90 mmHg confirmed before pregnancy or before 20 completed wk of gestation without a known causeHigh BP predating the pregnancy
Preexisting HTN with comorbid conditions
Preexisting HTN with superimposed preeclampsia
Gestational HTNNew-onset elevations of BP after 20 wk of gestation, often near term, in the absence of accompanying proteinuriaHTN that develops for the first time at ≥20+0 wk of gestationNew HTN presenting after 20 wk without significant proteinuriaNew onset of HTN after 20 wk of gestation without any maternal or fetal features of preeclampsia followed by return of BP to normal within 3 mo postpartumWhen de novo HTN is present after 20 wk of gestation in the absence of proteinuria and maternal organ/uteroplacental dysfunction
Gestational HTN with comorbid conditions
Gestational HTN with evidence of preeclampsia
Preeclampsia/eclampsiaHTN as defined above, associated with proteinuria (24-h excretion ≥300 mg), diagnosed after 20 wk of uneventful gestation up to 2 wk postpartumIn the absence of proteinuria, new-onset HTN with new onset of any of the followingPlatelet count <100,000/μl, serum creatinine >1.1 mg/dl, or doubling of concentration in absence of other renal diseaseTransaminitis to twice normal concentrationPulmonary edemaCerebral/visual symptomsGestational HTN with one or more of the followingNew proteinuriaOne or more adverse conditionsaOne or more severe complicationsbPreeclampsia is new HTN presenting after 20 wk with significant proteinuriaEclampsia is a convulsive condition associated with preeclampsiaHemolysis, elevated liver enzymes, and low platelet count syndromeSevere preeclampsia: preeclampsia with severe HTN and/or symptoms and/or biochemical and/or hematologic impairmentMultisystem disorder unique to human pregnancy characterized by HTN and involvement of one or more other organ systems and/or the fetusWhen de novo HTN is present after 20 wk of gestation in the presence of proteinuria and maternal organ/uteroplacental dysfunction
Preeclampsia/eclampsia superimposed on chronic HTNHTN diagnosed before or in early gestation and development of associated proteinuriaHTN along with the development of one or more of the following at ≥20 wkNone specifiedWoman with chronic HTN developing one or more of the systemic features of preeclampsia after 20 wk of gestationOne or more of the above features of preeclampsia (i.e., proteinuria and maternal organ/uteroplacental dysfunction) occur in addition to HTN
Resistant HTN
New or worsening proteinuria
One or more adverse conditionsa
One or more severe complicationsb
Other HTN effectsWhite coat HTN: elevated BP primarily in the presence of health care providersWhite coat HTN: BP that is elevated in the office but consistently normal outside of the office (<135/85 mmHg) by ABPM or HBPMNone specifiedWhite coat HTN: raised BP in the presence of a clinical attendant but normal BP otherwise as assessed by ABPM or HBPMWhite coat HTN: normal BP using 24-h ABPM in the first half of pregnancy
Transient hypertensive effect: elevated BP may be caused by environmental stimuli (e.g., the pain of labor)Secondary HTN: raised BP in the presence of an inciting factor such as
Masked hypertensive effect: BP that is consistently normal in the office (sBP<140 mmHg or dBP<90 mmHg) but elevated outside of the office (≥135/85 mmHg) by ABPM or repeated HBPMCKD (e.g., GN, reflux nephropathy, and adult polycystic kidney disease)
Renal artery stenosis
Systemic disease with renal involvement (e.g., diabetes mellitus or SLE)
Endocrine disorders (e.g., pheochromocytoma, Cushing syndrome, and primary hyperaldosteronism)
Coarctation of the aorta
  • ACOG, American College of Obstetrics and Gynecology; SOGC, Society of Obstetricians and Gynecologists of Canada; RCOG, Royal College of Obstetricians and Gynecologists; SOMANZ, Society of Obstetric Medicine of Australia and New Zealand; ISSHP, International Society for the Study of Hypertension in Pregnancy; HTN, hypertension; sBP, systolic BP; dBP, diastolic BP; ABPM:, ambulatory BP monitoring; HBPM, home BP monitoring.

  • a Adverse condition: involvement of organ systems, such as central nervous (headache, visual symptoms, seizure, etc.), cardiorespiratory (chest pain, hypoxia, poorly controlled HTN, etc.), hematologic (low platelet count, elevated international normalized ratio [INR] or partial thromboplastin time [PTT], etc.), renal (elevated creatinine, elevated uric acid, new indication for dialysis, etc.), hepatic (right upper quadrant pain, transaminitis, low plasma albumin, etc.), or fetoplacental system (abnormal fetal heart rate, oligohydramnios, stillbirth, etc.).

  • b Severe complications: complications of central nervous (e.g., eclampsia, posterior reversible encephalopathy syndrome [PRES], cortical blindness, Glasgow coma scale <13, stroke, transient ischemic attack [TIA], or reversible ischemic neurological deficit [RIND]), cardiorespiratory (e.g., uncontrolled severe HTN over 12 hours, despite use of three antihypertensive agents, oxygen saturation <90%, pulmonary edema, positive inotropic support, or myocardial ischemia or infarction), hematologic (platelet count <50×109/L or transfusion of any blood product), renal (AKI or new indication for dialysis), hepatic (INR>2 in the absence of disseminated intravascular coagulopathy [DIC] or warfarin), or fetoplacental system (abruption with evidence of maternal or fetal compromise, reverse ductus venosus A wave, or stillbirth).