Cephalexin is not believed to be harmful to an unborn baby.This medication falls under the United States Food and Drug Administration Pregnancy Category B, meaning that animal reproduction studies have shown no risk to a fetus in any trimester.
Cephalexin is a cephalosporin antibiotic used to fight bacterial infections. This medication has been used during various stages of pregnancy with no evidence of harm to the fetus according to Drugs.com.
Because there is still a potential risk, Cephalexin should not be prescribed during pregnancy unless there is a clearly established need. Women should tell their doctor if they are pregnant or plan to become pregnant while taking this medication.
Cephalexin can pass through the mother into breast milk, so women who are breastfeeding should not use Cephalexin without telling their doctor.