Will IV iron infusion therapy harm a pregnant woman's baby? What side effects are there?

No, the opposite. Taking iron while pregnant will not harm the baby. In fact, iron is essential for pregnant women. Women lose on average 500-1000cc of blood during delivery, so it's important for women to build up their iron and their blood count so prevent severe anemia after delivery. But in pregnancy, iron is essential for baby's development. Iv infusion can be essential for those women who need extra.