Do patients on Angiotensin-Converting Enzyme inhibitors (ACE-I) need to change their medication before or upon confirmation of pregnancy?

ACE Inhibitors Must Be Discontinued Before Pregnancy

ACE inhibitors and ARBs should be discontinued before pregnancy or immediately upon confirmation of pregnancy due to significant fetal risks including renal dysplasia, oligohydramnios, growth restriction, and potential fetal death.

Risks of ACE Inhibitors During Pregnancy

• ACE inhibitors and ARBs are contraindicated during pregnancy due to documented fetal toxicity, including renal or tubular dysplasia, oligohydramnios, growth retardation, ossification disorders of the skull, lung hypoplasia, and intrauterine fetal death 1
• These medications should be discontinued or replaced with an alternate medication before conception 1
• Even first-trimester exposure to ACE inhibitors has been associated with an increased risk of congenital anomalies (odds ratio 3.2,95% confidence interval 1.0 to 9.6) 2
• The American College of Cardiology and other guideline societies specifically recommend avoiding ACE inhibitors and ARBs during pregnancy due to these significant fetal risks 3

Timing of Medication Change

• ACE inhibitors should be discontinued before pregnancy rather than waiting until pregnancy is confirmed 1, 2
• For women already pregnant while taking an ACE inhibitor or ARB, the medication should be stopped as soon as possible after pregnancy confirmation 4
• Preconception counseling is crucial to discuss medication risks and make appropriate changes before conception occurs 2

Alternative Medications During Pregnancy

• Safe antihypertensive medications known to be effective during pregnancy include 1:

  • Methyldopa (preferred based on long-term safety data)
  • Labetalol (increasingly preferred due to reduced side effects)
  • Nifedipine and other calcium channel blockers (limited but generally favorable data)
  • Clonidine (limited data but considered acceptable)

• Beta-blockers may be used if necessary, though atenolol specifically is not recommended during pregnancy 1, 3

Special Considerations

• For women with chronic kidney disease and proteinuria, the benefit to kidney function may justify continuing ACE inhibitors until pregnancy is confirmed, but they should still be discontinued as soon as pregnancy is detected 4
• Diuretics are generally not recommended as first-line agents during pregnancy as they may reduce uteroplacental perfusion 1, 3
• Women with valve regurgitation or stenosis who are taking ACE inhibitors must also discontinue these medications before pregnancy 1

Management Approach

1. Identify all women of childbearing potential who are taking ACE inhibitors or ARBs
2. Provide counseling about the risks of these medications during pregnancy
3. Ensure effective contraception while on these medications
4. For women planning pregnancy, switch to pregnancy-safe alternatives before conception
5. For women who become pregnant while taking these medications, discontinue immediately and switch to a safer alternative

The evidence is clear and consistent across multiple guidelines that ACE inhibitors and ARBs pose significant risks to fetal development and should be avoided before and during pregnancy, with alternative antihypertensive medications used instead.