What to do for a patient with hypertension at 6 weeks gestation?

Management of Hypertension at 6 Weeks Gestation

For a patient with hypertension at 6 weeks gestation, methyldopa is the first-line treatment due to its established safety record in pregnancy, with labetalol as an effective alternative. 1

Diagnostic Evaluation

Before initiating treatment, perform:

• Confirmation of hypertension using validated devices for pregnancy (manual auscultatory or validated automated upper-arm cuff)
• Urine analysis for proteinuria (to identify pre-existing renal disease)
• Full blood count, liver enzymes, serum creatinine
• Ultrasound of kidneys and adrenals if secondary hypertension is suspected
• Assessment for risk factors for preeclampsia

Treatment Algorithm

Step 1: Determine Severity of Hypertension

• Mild: SBP 140-149 and DBP 90-99 mmHg
• Moderate: SBP 150-159 and DBP 100-109 mmHg
• Severe: SBP ≥160 and DBP ≥110 mmHg

Step 2: Initiate Treatment Based on Severity

• For mild hypertension (140-149/90-99 mmHg): Non-pharmacological management with close monitoring
• For moderate to severe hypertension (≥150/95 mmHg): Pharmacological treatment is recommended 2

Step 3: Medication Selection

1. First-line: Methyldopa (750 mg to 4 g per day in 3-4 divided doses)

   • Best safety record with long-term pediatric follow-up data
   • Start at 250 mg 2-3 times daily and titrate as needed 1, 3

2. Second-line: Labetalol (100 mg twice daily up to 2400 mg per day)

   • Alpha-beta blocker with vasodilatory properties
   • No evidence of teratogenicity 1

3. Third-line: Calcium channel blockers (mainly nifedipine)

   • Avoid sublingual or intravenous administration due to risk of rapid BP reduction
   • Do not combine with intravenous magnesium (risk of myocardial depression) 1

Step 4: Blood Pressure Targets

• Target BP: 140-150/90-100 mmHg
• Avoid excessive BP reduction to prevent compromised uteroplacental perfusion 4

Prevention of Preeclampsia

For women at high risk of preeclampsia (those with hypertension in previous pregnancy, chronic kidney disease, autoimmune disease, diabetes, or chronic hypertension), or moderate risk (first pregnancy in a woman >40 years, pregnancy interval >10 years, BMI >35 kg/m², family history of preeclampsia, multiple pregnancies):

• Initiate low-dose aspirin (75-162 mg) at weeks 12-36 1
• Consider oral calcium supplementation (1.5-2 g/day) if dietary intake is low (<600 mg/day) 1

Medications to Avoid

• ACE inhibitors and ARBs: Contraindicated due to severe fetotoxicity 4, 2
• Diuretics: Controversial due to potential reduction in plasma volume expansion and concern about promoting preeclampsia 1

Follow-up and Monitoring

• Regular BP monitoring throughout pregnancy
• Repeat urine analysis for proteinuria development
• Monitor for signs of preeclampsia after 20 weeks
• Consider ambulatory blood pressure monitoring (ABPM) to evaluate white coat hypertension 1, 5

Important Considerations

• Chronic hypertension in early pregnancy (before 20 weeks) increases risk of superimposed preeclampsia (20-25%), abruptio placentae, and cerebral hemorrhage 1
• Fetal complications include prematurity, growth restriction, stillbirth, and neonatal death 1
• No blood pressure threshold below which reassurance can be provided against development of preeclampsia 6
• Women with hypertension during pregnancy have increased risk of future cardiovascular disease and should undergo annual BP monitoring after delivery 4