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In its discussion of hydrochlorothiazide and pregnancy, the FDA warns that the routine use of diuretics like hydrochlorothiazide during a normal pregnancy is inappropriate and can expose the fetus and parent to unnecessary hazards.

Hydrochlorothiazide and Breastfeeding

Hydrochlorothiazide can cross from parent to child through breast milk.


While there are no scientific studies that suggest that hydrochlorothiazide can harm a developing fetus, the FDA says it could pose a risk to both the pregnant parent and child.

What pregnancy category is hydrochlorothiazide?

Hydrochlorothiazide is a Category B drug, which means that it should be safe during pregnancy if there is a clinical need, such as high blood pressure. In other words, the FDA only advises use of this drug during pregnancy if the benefits clearly outweigh potential harm.

Can you use diuretics during pregnancy?

The FDA says that using diuretics like hydrochlorothiazide during a normal pregnancy is not appropriate and that it could expose both parent and fetus to unnecessary harm.

What blood pressure meds are safe in pregnancy?

The American Heart Association says that no blood pressure medicine is proven safe during the first trimester, or first three months, of pregnancy. The association does list several blood pressure medications commonly prescribed for use during pregnancy, though. These antihypertensive drugs include:

  • Methyldopa (Aldomet)
  • β-receptor blockers, or beta blockers, like labetalol (Normodyne, Trandate)
  • Nifedipine (Procardia XL, Adalat CC, Afeditab CR)
  • Hydralazine (Apresoline)
  • Hydrochlorothiazide (Microzide)

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