I just thought I would post a list of all the drug category’s for use in pregnancy and breastfeeding and what they mean. I hope some of you find it useful


Category A

Drugs which have been taken by a large number of pregnant without any proven risk to the to the foetus or neonate

Category B1

Drugs which have been taken by only a limited number of pregnant women and women of childbearing age without an increase in the frequency of malformation or other direct or indirect harmful effects on the foetus having being observed. Studies in animals have not shown any evidence of any increased occurrence of foetal damage.


Category B2

Drugs which have been taken by only a limited number of pregnant women and women of childbearing age without an increase in the frequency of malformation or other direct or indirect harmful effects on the foetus having being observed. Studies in animals are inadequate or lacking but available data shows no evidence of any increased occurrence of foetal damage.

Category B3

Drugs which have been taken by a limited number of pregnant women without increase in malformations or other direct or indirect harmful effects being observed. Animal studies have shown an increase in foetal damage the significance of which is considered uncertain in humans


Category C

Drugs which have caused or are suspected of causing harmful effects on the fetus or neonate without causing malformations. Most of these effects will be reversible.

Category D

Drugs which have caused or are suspecting of causing an increased incidence of human foetal malformation or irreversible damage.