HYPERTENSION Gestational Hypertension

Mohammad Ilyas, M.D.

Assistant Clinical Professor

University of Florida / Health Sciences Center

Jacksonville, Florida USA

Outline

1. Definition, Regulation and Pathophysiology

2. Measurement of Blood Pressure, Staging of Hypertension and Ambulatory

Blood Pressure Monitoring

3. Evaluation of Primary Versus Secondary

4. Sequel of Hypertension and Hypertension Emergencies

5. Management of Hypertension (Non-Pharmacology versus Drug Therapy)

6. The Relation Between Hypertension: Obesity, Drugs, Stress and Sleep

Disorders.

7. Hypertension in Renal diseases and Pregnancies

8. Pediatric, Neonatal and Genetic Hypertension

Hypertension in Pregnancy

• Most common medical problem encountered during pregnancy

• 8% of pregnancies

• Third leading cause of maternal mortality, after

thromboembolism and non-obstetric injuries

• Maternal DBP > 110 is associated with ↑ risk of placental

abruption and fetal growth restriction

• Superimposed preeclampsia cause most of the

morbidity

Hypertension in Pregnancy

• 4 categories

1. Chronic Hypertension

2. Pregnancy Induced hypertension

3. Preeclampsia-eclampsia

4. Preeclampsia superimposed on chronic HTN

DEFINITION

Chronic hypertension, if blood pressure

elevation >140/90 before 20 weeks and persists

≥12 weeks postpartum

Gestational hypertension of pregnancy, if blood

pressure returns to normal by 12 weeks

postpartum

Chronic Hypertension

Treatment of mild to moderate chronic hypertension neither benefits the fetus nor prevents preeclampsia.

Excessively lowering blood pressure may result in decreased placental perfusion and adverse perinatal outcomes.

When BP is 150 to 180/100 to 110 mm Hg, pharmacologic treatment is needed to prevent maternal end-organ damage.

Treatment of Chronic Hypertension

Methyldopa , labetalol, and nifedipine most common

oral agents.

AVOID: ACEI and ARBs, atenolol, thiazide diuretics

Women in active labor with uncontrolled severe chronic

hypertension require treatment with intravenous

labetalol or hydralazine.

Pregnancy Induced Hypertension

(Gestational)

• Usually mild and later in pregnancy

• BP ≥140/90 mmHg (severe when ≥160/≥110 mmHg)

• Previously normotensive

• ≥20 weeks of gestation

• No renal or other systemic involvement

• No proteinuria or new signs of end-organ dysfunction

• Resolves 12 weeks postpartum

• May become preeclampsia

Gestational Hypertension to Preeclampsia

The pathophysiology of gestational hypertension is unknown.

Different diseases with a similar phenotype (hypertension)

Primiparity is a strong risk factor for preeclampsia, but not for GH

The recurrence risk for gestational hypertension is ~40% (for PE 5%)

Total blood and plasma volumes are significantly lower in women

with preeclampsia (mean 2660 mL/m2 and 1790 mL/m2,

respectively) than in women with gestational hypertension (3139

mL/m2 and 2132 mL/m2, respectively)

GH versus PE

Features Gestational HTN Preeclampsia

Hypertension + ++

Primiparity + 10%

Recurrence 25-45 % 5%

Total Plasma Volume 2132 mL/m2 (mean) 1790 mL/m2 (mean)

Proteinuria Negative Positive

Gestational age Usually late

(>20weeks)

Usually early

(<20 weeks)

Complications Rarely Increase risk

Post partum Resolve < 12 weeks Resolve < 6 weeks

RISK OF PROGRESSION TO PREECLAMPSIA

Preeclampsia develops in 15 to 25 % of women with initial GH,

Early onset of GH are more likely to progress to preeclampsia

(33 versus 37 weeks)

40 to 50 % of women with GH presenting at ≤30 weeks

developed preeclampsia as compared with about 10 % of

those who developed gestational hypertension at ≥36 weeks

Women who go on to develop preeclampsia have higher total

vascular resistance at presentation than women with

uncomplicated GH

PERINATAL OUTCOME

Pregnancy outcomes of patients with non-severe gestational

hypertension are generally favorable.

The mean birth weight and rates of fetal growth restriction,

preterm birth, abruption, and perinatal death are similar to those

in the general obstetrical population.

Severe gestational hypertension appear to be at increased risk of

maternal and perinatal morbidity

These pregnancies have significantly higher rates of preterm

delivery, small for gestational age infants, and abruptio placentae

MANAGEMENT

Non-severe gestational hypertension, monitoring blood

pressure once or twice weekly and weekly assessment of

proteinuria, platelet count, and liver enzymes

Patient education and counseling

Fetal assessment, monitor fetal movement daily

No antihypertensive therapy — unless hypertension is

severe (≥160 mmHg systolic or ≥110 mmHg diastolic)

No antenatal glucocorticoids

Timing of delivery at 370/7ths to 386/7ths weeks

Intrapartum management

administer magnesium sulfate for seizure prophylaxis

Preeclampsia • New onset HTN

• After 20 weeks of gestation, or

• Early post-partum, previously normotensive

• Resolves within 48 hrs postpartum

• With the following (Renal or other systemic)

• Proteinuria > 300 mg/24hr

• Oliguria or Serum-plasma creatinine ratio > 0.09 mmol/L

• Headaches with hyperreflexia, eclampsia, clonus or visual disturbances

• ↑ LFTs, glutathione-S-Transferase alpha 1-1, alanine aminotransferase or

right abdominal pain

• Thrombocytopenia, ↑ LDH, hemolysis, DIC

• 10% in primigravid

• 20-25% with history of chronic HTN

Diagnostic Criteria for Preeclampsia

1. SBP of 140 mm Hg or more or a DBP of 90 mm Hg or more on two occasions at least six hours apart after 20 weeks of gestation AND

2. Proteinuria – 300 mg in a 24-hour urine specimen or 1+ or greater on urine dipstick testing of two random urine samples collected at least four hours apart.

A random urine protein/creatinine ratio < 0.21 indicates that significant proteinuria is unlikely with a NPV of 83%.

Generalized edema (affecting the face and hands) is often present in patients with preeclampsia but is not a diagnostic criterion.

Mild vs. Severe Preeclampsia

Mild Severe

Systolic arterial pressure 140 mm Hg – 160 mm Hg ≥160 mm Hg

Diastolic arterial pressure 90 mm Hg – 110 mm Hg ≥110 mm Hg

Urinary protein <5 g/24 hr

Dipstick +or 2 +

≥5 g/24 hr

Dipstick 3+or 4+

Urine output >500 mL/24 hr ≤500 mL/24 hr

Headache No Yes

Visual disturbances No Yes

Epigastric pain No Yes

Maternal Risk Factors

• First pregnancy

• Age younger than 18 or older than 35

• Prior h/o preeclampsia

• Black race

• Medical risk factors for preeclampsia - chronic HTN,

renal disease, diabetes, anti-phospholipid syndrome

• Twins

• Family history

Etiology

Exact mechanism not known

• Immunologic

• Genetic

• Placental ischemia

• Endothelial cell dysfunction

• Vasospasm

• Hyper-responsive response to vasoactive hormones (e.g.

angiotensin II & epinephrine)

Risk Factors

FACTOR RISK RATIO

Renal disease 20:1

Chronic hypertension 10:1

Antiphospholipid syndrome 10:1

Family history of PIH 5:1

Twin gestation 4:1

Nulliparity 3:1

Age > 40 3:1

Diabetes mellitus 2:1

African American 1.5:1

Symptoms of preeclampsia

• Visual disturbances

• Headache

• Epigastric pain

• Rapidly increasing or nondependent edema - may

be a signal of developing preeclampsia

• Rapid weight gain - result of edema due to

capillary leak as well as renal Na and fluid retention

Pathophysiology

Organ involvement

• Airway edema

• Cardiac

• Renal

• Hepatic

• Uterine

Upper airway edema

• Upper airway edema

• Laryngeal edema

• Airway obstruction

• Potential for airway compromise or difficulty in intubation

Cardiac/Pulmonary

• Increased CO & SVR

• CVP normal or slightly increased

• Plasma volume reduced

• Pulmonary edema

• Decrease oncotic/colloid pressure

• Capillary/endothelial damage leak

• Vasoconstriction

• increase PWP and CVP

• Occurs 3 % of preeclamptic patients

Hepatic

• Usually mild

• Severe PIH or preeclampsia complicated by HELLP

periportal hemorrhages

ischemic lesion

generalized swelling

hepatic swelling

epigastric pain

Renal

• Adversely affected proteinuria

• GFR and CrCl decrease

• BUN increase, may correlate w/ severity

• RBF compromised

• ARF w/ oliguria – PIH, esp. w/ abruption, DIC, HELLP

*Oliguria + renal failure may occur in the absence of hypovolemia. Be careful w/ hydration pulmonary edema*

Uterine

• Activity increased

• Hyperactive/hypersensitive to oxytocin

• Preterm labor – frequent

• Uterine/placental blood flow – decreased by 50-70%

• Abruption – incidence increased

Morbidity / Mortality

Maternal complications:

• Leading cause of maternal death in PIH is intracranial hemorrhage

• Seizures

• Pulmonary edema

• ARF

• Proteinuria

• Hepatic swelling with or without liver dysfunction

• DIC (usually associated with placental abruption and is uncommon

as a primary manifestation of preeclampsia)

Morbidity / Mortality

Fetal complications:

• Abruptio placentae

• IUGR

• Premature delivery

• Intrauterine fetal death

HELLP Syndrome

• Hemolysis

• Elevated Liver enzymes

• Low Platelets

• < 36 wks

• Malaise (90%), epigastric pain (90%), N/V (50%)

• Self-limiting

• Multi-system failure

Diagnosis Criteria for HELLP

HTN SPB is ≥160 mmHg or DPB is ≥110 mmHg

Proteinuria ≥0.3 grams in a 24-hour urine specimen or

protein (mg/dL)/creatinine (mg/dL) ratio ≥0.3

Platelet count <100,000/microliter

Serum creatinine >1.1 mg/dL or doubling of serum

creatinine in the absence of other renal disease

Liver transaminases at least twice the normal

concentrations

Pulmonary edema

Cerebral or visual symptoms

HELLP Syndrome

• Hemostasis is not problematic unless PLT < 40,000

• Rate of fall in PLT count is important

• Regional anesthesia - contraindicated fall is sudden

• PLT count normal within 72 hrs of delivery

• Thrombocytopenia may persist for longer periods.

• Definitive cure is delivery

Treatment

• Management of maternal hemodynamics & prevention

of eclampsia are key to a favorable outcome

• MgSO4 - Rx of choice for preeclampsia.

• Does not significantly reduce systemic BP at the serum concentration that are efficacious in treating preeclampsia

• Goals

• Control BP

• Prevent seizures

• Deliver the fetus

Controlling the HTN

• Hydralazine

• Labetalol

• Nitroglycerin

• Nifedipine

• Esmolol

• Na Nitroprusside – risk of cyanide toxicity in the fetus

Preventing Seizures

• MgSO4 - Drug of choice. Narrow therapeutic index

• Reduce > 50% w/o any serious maternal morbidity

• 4g IV Bolus over 10 minutes, then infusion @ 1g/hr

• Renal failure - rate of infusion by serum Mg levels

• Plasma Level should be between 4-6 mmol/L

• Monitor clinical signs for toxicity

• Toxic: 10 ml of 10% Ca Gluconate IV slowly

MgSO4 Toxicity

• 5-10 mEq/L – Prolonged PR, widened QRS

• 11-14 mEq/L – Depressed tendon reflexes

• 15-24 mEq/L – SA, AV node block, respiratory paralysis

• >25 mEq/L - Cardiac arrest

Quiz

Quiz 1. Which of the following is NOT true

about Hypertension in Pregnancy ?

A. HTN is the Most common medical problem encountered during pregnancy

B. Majority of the of pregnancies complicate with HTN.

C. Third leading cause of maternal mortality, after

thromboembolism and non-obstetric injuries

D. Maternal DBP > 110 is associated with ↑ risk of placental

abruption and fetal growth restriction

E. Superimposed preeclampsia cause most of the morbidity

Quiz 1. Which of the following is NOT true

about Hypertension in Pregnancy ?

A. HTN is the Most common medical problem encountered during pregnancy

B. Majority of the of pregnancies complicate with HTN.

C. Third leading cause of maternal mortality, after

thromboembolism and non-obstetric injuries

D. Maternal DBP > 110 is associated with ↑ risk of placental

abruption and fetal growth restriction

E. Superimposed preeclampsia cause most of the morbidity

Quiz 2. Which of the following is the

RISK for progression to preeclampsia?

A. Gestational diabetes

B. Gestational hypertension

C. Late onset of GH are more likely to progress to

preeclampsia

D. Low total vascular resistance

Quiz 2. Which of the following is the

RISK for progression to preeclampsia?

A. Gestational diabetes

B. Gestational hypertension

C. Late onset of GH are more likely to progress to

preeclampsia

D. Low total vascular resistance

Quiz 3. Hypertension in Pregnancy can be

categorized in the following categories

EXCEPT?

A. Chronic Hypertension

B. Malignant hypertension

C. Pregnancy Induced hypertension

D. Preeclampsia-eclampsia

E. Preeclampsia superimposed on chronic HTN

Quiz 3. Hypertension in Pregnancy can be

categorized in the following categories

EXCEPT?

A. Chronic Hypertension

B. Malignant hypertension

C. Pregnancy Induced hypertension

D. Preeclampsia-eclampsia

E. Preeclampsia superimposed on chronic HTN

Quiz 4. Which of the following statement about

Gestational Hypertension is TRUE?

A. The pathophysiology of gestational hypertension is known.

B. GH and PE are same diseases with a different phenotype

(hypertension)

C. Primiparity is a weak risk factor for preeclampsia, but not

for GH

D. The recurrence risk for gestational hypertension is ~40%

(for PE 5%)

E. Total blood and plasma volumes are significantly higher in

preeclampsia than in women with gestational

hypertension

Quiz 4. Which of the following statement about

Gestational Hypertension is TRUE?

A. The pathophysiology of gestational hypertension is known.

B. GH and PE are same diseases with a different phenotype

(hypertension)

C. Primiparity is a weak risk factor for preeclampsia, but not

for GH

D. The recurrence risk for gestational hypertension is ~40%

(for PE 5%)

E. Total blood and plasma volumes are significantly higher in

preeclampsia than in women with gestational

hypertension

Quiz 5. All of the following are required for

management of GH, EXCEPT?

A. Monitoring blood pressure once or twice weekly

B. Weekly assessment of proteinuria, platelet count, and

liver enzymes

C. Patient education and counseling

D. No antihypertensive therapy — unless hypertension is

severe (≥160 mmHg systolic or ≥110 mmHg diastolic)

E. Antenatal glucocorticoids

Quiz 5. All of the following are required for

management of GH, EXCEPT?

A. Monitoring blood pressure once or twice weekly

B. Weekly assessment of proteinuria, platelet count, and

liver enzymes

C. Patient education and counseling

D. No antihypertensive therapy — unless hypertension is

severe (≥160 mmHg systolic or ≥110 mmHg diastolic)

E. Antenatal glucocorticoids