Gestational hypertension

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

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 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 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 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

Gestational hypertension

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