Home
> Is This Safe When Breastfeeding?
> Medications
Pregnancy Risk Categories
Per Thomas
W. Hale, PhD (Medications
and Mothers' Milk, 2002, p.15):
Pregnancy
Risk Categories have been assigned to almost all medications by
their manufacturers and are based on the level of risk the drug
poses to the fetus during gestation. They are not useful in
assigning risk via breastfeeding [emphasis added]...
Unfortunately they do not indicate the importance of when during
gestation the medication is used, since some drugs are more dangerous
during certain trimesters of pregnancy.
| A |
CONTROLLED
STUDIES SHOW NO RISK:
Adequate, well-controlled studies in pregnant women have failed
to demonstrate a risk to the fetus in any trimester of pregnancy.
|
| B |
NO EVIDENCE
OF RISK IN HUMANS:
Adequate, well-controlled studies in pregnant women have not
shown increased risk of fetal abnormalities despite adverse
findings in animals, or, in the absence of adequate human studies,
animal studies show no fetal risk. The chance of fetal harm
is remote, but remains a possibility.
|
| C |
RISK
CANNOT BE RULED OUT:
Adequate,well-controlled human studies are lacking, and animal
studies have shown a risk to the fetus or are lacking as well.
There is a chance of fetal harm if the drug is administered
during pregnancy; but the potential benefits may outweigh the
potential risks.
|
| D |
POSITIVE
EVIDENCE OF RISK:
Studies in humans, or investigational or post-marketing data,
have demonstrated fetal risk. Nevertheless, potential benefits
from the use of the drug may outweigh the potential risk. For
example, the drug may be acceptable if needed in a life-threatening
situation or serious disease for which safer drugs cannot be
used or are ineffective.
|
| X |
CONTRAINDICATED
IN PREGNANCY:
Studies in animals or humans, or investigational or post-marketing
reports, have demonstrated positive evidence of fetal abnormalities
or risks which clearly outweighs any possible benefit to the
patient. |
A few sources of information on medication use during pregnancy
Drugs
in Pregnancy and Breastfeeding from perinatology.com
Motherisk
(phone 416-813-6780) at The Hospital for Sick Children in Toronto,
Ontario, Canada. Call or visit their website for evidence-based
information about the safety or risk of drugs, chemicals and disease
during pregnancy and lactation.
Drugs
in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal
Risk by Gerald G. Briggs, Roger K. Freeman and Sumner J. Yaffe
Page last modified:
03/03/2005
Added to website: 2/13/03
