Why parenteral Fe is contraindicated in 1st trimester of pregnancy?

Why parenteral Fe is contraindicated in 1st trimester of pregnancy?

Parenteral iron (iron given by injection or infusion) is generally not recommended during the first trimester of pregnancy unless there is a specific medical indication, such as severe anemia that cannot be treated with oral iron or other reasons where the potential benefits outweigh the potential risks.

This is because the first trimester is a critical period for fetal development, and there is a theoretical concern that parenteral iron may cause harm to the developing fetus. There is also limited data on the safety of parenteral iron during this period, and it is generally recommended to use oral iron supplements as the first-line treatment for anemia during pregnancy, whenever possible.

However, if oral iron supplements are not tolerated or effective, and intravenous iron is deemed necessary, the benefits of parenteral iron therapy should be carefully weighed against the potential risks to the fetus. In these cases, the lowest effective dose of iron should be used, and the mother and fetus should be carefully monitored for any adverse effects.