|Written by Dr.Md.Redwanul Huq (Masum)|
|Monday, 20 June 2011 12:23|
Pregnant woman and the newborn infant in breast feeding both of them need safety. So, caution in use of drugs in pregnancy and during lactation is mandatory. The knowledge of risk-benefit ratio of different drugs should be in mind of the doctor while prescribing a pregnant or lactating lady.Definitions of Pregnancy categories of drugs and a table showing pregnancy categories of drugs and safety of drugs in lactation are given here.
Definitions of Pregnancy categories of drugs:
On the basis of the potentiality for producing birth defects drugs in pregnancy are grouped into 1 of 5 categories which are A,B, C, D and X. Drugs of class A and B are considered safe and can be used routinely.
Pregnancy Category A : Controlled studies in pregnant women fail to detect risk to the fetus in the first trimester and no evidence of risk in later trimesters. The possibility of harm to the fetus appears remote by using the drugs of pregnancy category A.
Pregnancy Category B : Presumed safety on the basis of animal studies, with no controlled study in pregnant women, or animal studies have shown an adverse effect which was not confirmed in controlled studies in women in the first trimester and there is no evidence of risk to the fetus in later trimesters.
Pregnancy Category C : Studies in women and animals are not available or studies in animals have shown adverse effects on the fetus and there is no controlled study in women. Drugs should be given in pregnancy only if the potential benefits justify the potential risk to the fetus.
Pregnancy Category D : There is positive evidence of risk to the human fetus (unsafe), however in a life-threatening illness the potential risk may be justified if there are no other alternatives.
Pregnancy Category X : Highly unsafe: risk of use outweighs any potential benefit. Drugs in this category are contraindicated in pregnant women or in a woman who may become pregnant.
Table showing safety of drugs in pregnancy and lactation links are –