Prevention and Treatment of Hypertension in Pregnancy

Hypertension

Systolic blood pressure (sBP) greater than or equal to 140 mmHg and/or Diastolic blood pressure (dBP) greater than or equal to 90 mmHg of at least two measurements.

Non-severe (mild to moderate) hypertension

Systolic blood pressure of 140 mm Hg or more or diastolic blood pressure of 90 mm Hg.

Severe hypertension

Systolic blood pressure of 160 mm Hg or more or diastolic blood pressure of 110 mm Hg or more.

Chronic hypertension in pregnancy

Hypertension confirmed preconception or prior to 20 weeks; (including pregnant women entering pregnancy on antihypertensive therapy with well controlled BP levels), and does not resolve within 3 months postpartum.

Women may also be diagnosed with chronic hypertension retrospectively, e.g. where a woman with hypertension in pregnancy remains hypertensive 3 months following the birth.

Gestational hypertension

Hypertension developing after 20 weeks of gestation, without proteinuria and without features of organ dysfunction, with blood pressure levels returning to normal within 3 months postpartum.

At first presentation, this diagnosis might include some women (up to 25%) who are developing preeclampsia but have not yet developed organ manifestations.

Preeclampsia

Diagnosis:

Occurrence of new-onset hypertension, after 20 weeks of pregnancy and the coexistence of 1 or more of the following new-onset conditions:

1.    new-onset proteinuria or

2.    new-onset significant organ dysfunction

and resolves within 3 months postpartum.

Proteinuria

-  Protein/creatinine ratio ≥ 30 mg/mmol (= 0.3 mg%)

- Proteinuria ≥ 300 mg/dL of protein or more in a 24-hour urine collection

-  Dipstick proteinuria greater than or equal to 2+ proteinuria

Significant organ dysfunction

-  Blood: Platelet count <100,000/microL

-  Kidney: Serum creatinine >1.1 mg/dL or doubling of the creatinine concentration in the absence of other renal disease

-  Liver: transaminases at twice the upper limit of the normal.

-  Lung: Pulmonary edema

-  Brain: altered mental status, blindness, stroke, clonus, severe headaches or persistent visual scotomata

Non-severe pre-eclampsia

-  Pre-eclampsia with no features of severity or concern.

Severe pre-eclampsia

Pre-eclampsia with any of the following features of severity:

·  Severe Hypertension: Systolic blood pressure of 160 mm Hg or more, or diastolic blood pressure of 110 mm Hg or more on two occasions at least 4 hours apart (unless antihypertensive therapy is initiated before this time)

·  Thrombocytopenia: Platelet count less than 100,000 /mm³.

·  Impaired liver function that is not accounted for by alternative diagnoses and as indicated by abnormally elevated blood concentrations of liver enzymes (ALT, AST) to more than twice the upper normal limit,

· Renal insufficiency Serum creatinine concentrations greater than 1.1 mg/dL or a doubling of the serum creatinine concentration in the absence of other renal disease or oliguria.

· Persistent right upper quadrant or epigastric pain unresponsive to medications.

· New-onset recurring headaches; unresponsive to medication, not accounted for by any alternative diagnoses.

· Visual symptoms (photopsia, scotomata, cortical blindness, retinal vasospasm).

·  Pulmonary edema.

·  Failure of fetal growth or abnormal doppler findings

Superimposed Preeclampsia

-  Where a woman with pre-existing hypertension develops systemic features of preeclampsia after 20 weeks gestation:

▪️  New-onset proteinuria

▪️   New-onset feature of severe pre-eclampsia

Imminent eclampsia

-  Defined as at least two of the following signs and/or symptoms

1.  Ongoing or recurring severe headaches

2.  Visual disturbance

3.  Altered level of consciousness

4.  Hyperreflexia and/or sustained clonus

Eclampsia

-  Defined by new-onset tonic/clonic, focal, or multi-focal seizures; in the absence of other causative conditions such as epilepsy, cerebral arterial ischemia and/or infarction, intracranial hemorrhage, or drug use.

HELLP syndrome

-   (Hemolysis, Elevated Liver enzymes, Low Platelets) probably represents a severe form of preeclampsia, use the following criteria to make the diagnosis:

▪️   Lactate dehydrogenase (LDH) elevated to 600 IU/L or more, and

▪️   Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) elevated more than twice the upper limit of normal, and

▪️   Platelets count less than 100,000 /mm³.

Expectant

management

Refers to safe prolongation of the pregnancy, with maternal and fetal monitoring guiding clinically indicated treatment, instead of immediate birth.

Multidisciplinary

team

May include (as relevant to the clinical circumstances) obstetrician, midwife, obstetric physician, anaesthetist, neonatologist/paediatrician experienced in the care of women with hypertension in pregnancy.

Mean arterial

pressure (MAP)

MAP is calculated by using a validated blood pressure machine or by:

▪️ The sum of sBP plus twice the dBP = (𝑠BP + 2 x 𝑑BP) divided by 3

Definitive Intervention

Refers to delivery of fetus and placenta by initiation of labor or by Cesarean Section.