A young adult female client who is planning to become pregnant asks the nurse if she can continue taking isotretinoin for cystic acne. Which information is most important for the nurse to provide this client?

Breastfeeding is not recommended while taking this medication.

Do not take multiple vitamins that contain vitamin A while taking this drug.

Baseline liver function results must be obtained during therapy.

Discontinue this medication one month before attempting to conceive.