CHRONIC HYPERTENSION IN PREGNANCY

1. Case 5
Dr Barik

2. A 35-year-old woman elder primi and has a 5-year history of
hypertension wants to become pregnant. She has stopped using
contraception. Her only medication is lisinopril at a dose of 10 mg
per day. Her blood pressure is 124/68 mm Hg,and her body-mass
index (the weight in kilograms divided by the square of the height
in meters) is 27.
Pregnancy-related deaths(3201 in US,
1991-1997-16%

3. Classification of Hypertension in Pregnancy
From Gifford RW, August PA, Cunningham G, et al: Report of the National High Blood Pressure
Education Program Working Group on High Blood Pressure in Pregnancy.
Am J Obstet Gynecol 183:S1, 2000
Hypertension (blood pressure ≥140 mm Hg systolic or ≥90 mm
Chronic hypertension Hg diastolic) present before pregnancy or that is diagnosed
before the 20th week of gestation
New hypertension with a blood pressure of 140/90 mm Hg on
two separate occasions, without proteinuria, arising de novo
Gestational hypertension
after the 20th week of pregnancy. Blood pressure normalizes
by 12 weeks post partum.
Increased blood pressure above the patient's baseline, a
Preeclampsia superimposed on chronic hypertension
change in proteinuria, or evidence of end-organ dysfunction
Proteinuria (>0.3 g during 24 hours or ++ in two urine
samples) in addition to new hypertension. Edema is no longer
included in the diagnosis because of poor specificity. When
Preeclampsia-eclampsia
proteinuria is absent, suspect the disease when increased
blood pressure is associated with headache, blurred vision,
abdominal pain, low platelets, or abnormal liver enzymes.

4. Gestational
Hypertension – 3.7% in Diagnosis
150,000 (National
Center for Health
Statics, 2001)
CHRONIC
HYPERTENSION

5. •BP ≥140/90 mmHg before pregnancy
or diagnosed before 20weeks’
gestation (not attributable to
gestational trophoblastic disease)
or
•Hypertension first diagnosed after
20weeks’ gestation and persistent after
12weeks’ postpartum
Underlying hypertension-Essential familial hypertension (90%)

6. •BP≥ 140/90mmHg for first time during
pregnancy
•No proteinuria
•BP returns to normal < 12 weeks’ postpartum
•Final diagnosis made only postpartum
•May have other signs or symptoms of
preeclampsia, for example, epigastric discomfort
or thrombocytopenia

7. Essential familial hypertension (hypertensive vascular disease)
Obesity
Atrterial abnormalities
Renovascular hypertension
Coarctation of the aorta
Endocrine diorders
Diabetes mellitus
Cushing syndrome
Primary aldosteronism
Pheochromocytoma
Thyrotoxicosis
Glomerulonephritis (acute and chronic)
Renoprival hypertension
Chronic glomerulonephritis
Chronic renal insufficiency
Diabetic nephropathy
Connetive tissue disease
Lupus erythematosus
Systemic sclorosis
Periarteritis nodosa
Polycystic kidney disease
Acute renal failure

8. INCIDENCE
Nulliparous women BMI (Kg/m2)
Incidence : 5% (wide Morbidity (%)
variation) <19.8
Influence by Parity, race, 4.3
ethnicity, genetic >35
predisposition
Nulliparous 13.3
Total :7.6% / severe : Gestation
3.3% (Hauth, 2000)
Risk factor twin
Chronic hypertension, 13
multifetal gestation, single
maternal old age(>35 5
yrs), obesity, African-

9. 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

10. New-onset proteinuria≥ 300mg/24hours in
hypertensive women but no proteinuria
before 20 weeks’ gestation.
A sudden increase in proteinuria or blood
pressure or platelet count <100,000/mm3 in
women with hypertension and roteinuria
before 20weeks’ gestation

12. 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.

13. Antihypertensive Therapy Prior to
and During Pregnancy
1. What is the proper management of young women
with mild hypertension?
2. What are the benefits of treating mild
hypertension in pregnancy?
3. Is pharmacological treatment of mild
hypertension harmful to mothers, fetuses, and
infants?
4. Are particular antihypertensive drugs more
ffective or harmful than others?

14. What Are the Benefits of Treating
Mild Hypertension in Pregnancy?
 Data are insufficient to either prove or
disprove effects in perinatal outcome
• All trials had inadequate sample size
• Most were unblinded
• Few women enrolled in first trimester
• 15 different drugs or combinations were
studied
 Definite need for multicenter trials

15. What is the Proper Management of
Young Women with Hypertension?
 No report that addressed the effect of blood
pressure control before conception on fetal
outcomes
 Women of reproductive age are excluded from
randomized trials
 Only 3 trials in women aged 30-54 years
• 8,565 studied
• Little data in women < 40 years

16. 16

19. Acute Medical Therapy
• Hydralazine
• Labetalol
• Nifedipine
• Nitroprusside
• Clonidine

20. Hydralazine
• Dose: 5-10 mg every 20 minutes
• Onset: 10-20 minutes
• Duration: 3-8 hours
• Side effects: headache, flushing, tachycardia,
lupus like symptoms
• Mechanism: peripheral vasodilator

21. Labetalol
• Dose: 20 mg, then 40, then 80 every 20
minutes, for a total of 220mg
• Onset: 1-2 minutes
• Duration: 6-16 hours
• Side effects: hypotension
• Mechanism: Alpha and Beta blockade

22. Nifedipine
• Dose: 10 mg po, not sublingual
• Onset: 5-10 minutes
• Duration: 4-8 hours
• Side effects: chest pain, headache, tachycardia
• Mechanism: CA channel blockade

23. Clonidine
• Dose: 1 mg po
• Onset: 10-20 minutes
• Duration: 4-6 hours
• Side effects: unpredictable, avoid rapid
withdrawal
• Mechanism: Alpha agonist, works centrally

24. Nitroprusside
• Dose: 0.2 – 0.8 mg/min IV
• Onset: 1-2 minutes
• Duration: 3-5 minutes
• Side effects: cyanide accumulation,
hypotension
• Mechanism: direct vasodilator

25. Seizure Prophylaxis
• Magnesium sulfate
• Loading dose of 4 to 6 g diluted in 100 mL of
normal saline, given IV over 15 to 20 minutes,
followed by a continuous infusion of 1-2 g per
hour
• Monitor urine output, RR and DTR’s
• With renal dysfunction, may require a lower
dose

26. • Low-dose aspirin (75 to 81 mg daily) has small to moderate
benefits for the prevention of preeclampsia (NNT = 72), preterm
delivery (NNT = 74), and fetal death (NNT = 243). The benefit of
aspirin is greatest (NNT = 19) for prevention of preeclampsia in
women at highest risk (previous severe preeclampsia, diabetes,
chronic hypertension, renal disease, or autoimmune disease). –
B
• For women with mild preeclampsia, delivery is generally not
indicated until 37 to 38 weeks of gestation and should occur by
40 weeks. – C

27. KEY RECOMMENDATIONS FOR PRACTICE
• In women without end-organ damage, chronic hypertension in
pregnancy does not require treatment unless the patient's blood
pressure is persistently greater than 150 to 180/100 to 110 mm
Hg. – C
• Calcium supplementation decreases the incidence of
hypertension and preeclampsia, respectively, among all women
(NNT = 11 and NNT = 20), women at high risk of hypertensive
disorders (NNT = 2 and NNT = 6), and women with low calcium
intake (NNT = 6 and NNT = 13). – A