Many acne medications should not be used by women who are or may become pregnant. This is particularly true of isotretinoin, an oral retinoid. Isotretinoin is absolutely not recommended for pregnant women because of a very high risk of miscarriage or severe birth defects. The Food and Drug Administration (FDA) strictly monitors isotretinoin and requires women to have two negative pregnancy tests prior to receiving a prescription.

Further, women must have monthly pregnancy tests throughout the course of isotretinoin treatment, as well as additional tests right after finishing the last dose of the drug and one month after finishing the last dose of the drug. It is not known if this medication passes into breast milk and breastfeeding is not recommended during therapy.

Topical retinoids are typically not recommended for women who are or may become pregnant, or those who are breastfeeding. It is currently unknown whether these drugs can have an adverse effect on developing fetuses or nursing children.  

Most antibiotics are safe to use during pregnancy when monitored. However, these may enter breast milk and breastfeeding is typically not recommended while taking these medications. The use of tetracycline and its derivatives is not advised during pregnancy or breastfeeding. These drugs can inhibit bone growth and discolor permanent teeth in developing fetuses, as well as in children who are nursing.

Antiandrogens are also considered unsafe to use during pregnancy as they may cause birth defects. These drugs are also not recommended for women who are breastfeeding because it is unknown whether they can be passed through breast milk.