If you take pinworm medicine while pregnant, does it affect the baby?

Nope, you're good: Pinworm infections are usually treated with a one time dose of Vermox (mebendazole) 100 mg. It's a category c medicine and if used short term, it can be used safely in pregnancy. Usually we treat the whole family, chew it before you swallow it, and it can be repeated in 2 weeks if needed. Most patients do great with just one dose. It should not affect your baby even if retreatment is done.