ACE inhibitors & ARBs

• Hypertension outside pregnancy (with diabetes/CKD)
• Heart failure (non-pregnant)

Block ACE (or angiotensin II receptor) → ↓ angiotensin II, ↓ aldosterone → ↓ SVR and renal Na⁺ retention.

• T2/T3: oligohydramnios, renal dysgenesis, calvarial hypoplasia, IUFD
• Switch preconception — do NOT wait for positive test
• Angio-oedema risk universal

Enalapril

5–20 mg BD (non-pregnant)

Ramipril

2.5–10 mg OD (non-pregnant)

Losartan

50–100 mg OD (non-pregnant)

• AbsolutePregnancy (T2/T3 fetotoxicity, ↑ T1 malformations)
• AbsoluteBilateral renal artery stenosis
• AbsoluteHistory of ACE-induced angio-oedema
• AbsoluteConcurrent aliskiren in diabetes

• Dry cough (ACEi)
• Hyperkalaemia, ↑ creatinine
• Angio-oedema
• First-dose hypotension

• • T1: ↑ cardiovascular and CNS malformations (~2× baseline)
• • T2/T3: renal tubular dysgenesis, oligohydramnios, skull hypoplasia, IUFD
• • Neonatal hypotension and anuria if exposed late

• K⁺-sparing diuretics / K⁺ supplements

  Avoid

  Severe hyperkalaemia

• NSAIDs

  Avoid

  Triple whammy AKI

• Lithium

  Caution

  ↑ lithium levels

• 💡 Every pre-pregnancy counselling clinic checks for ACEi/ARB and switches to labetalol or nifedipine
• 💡 Alert card and shared decision-making for women planning pregnancy