MRI and Pregnancy

At present, there is no known risk of MR scanning of a pregnant woman to the developing fetus, and no known mechanism of potential risk. Nonetheless, the possibility that risks may be discovered in the future cannot be ruled out.

Given this uncertainty, COUHES recommends that women who are pregnant should not participate as subjects in MR research studies.  Accordingly, COUHES recommends that in any MR studies all females of child bearing age be screened for pregnancy and informed of the possible risks to a fetus associated with MR scanning.

The method of screening will be left to the researcher but will be subject to review by COUHES. The consent form used in any MR research study must include a discussion of the available data on the risk of MR and pregnancy.

Many women are not aware that they are pregnant, especially early in the pregnancy when the risk to the fetus may be greater.  Accordingly, irrespective of the method of screening initially used, the researcher must have pregnancy test kits available for subjects to use at their discretion.

Suggested language for investigators to use is as follows:

“Most studies of MR during pregnancy show no evidence of risk to the fetus. However, given the limited data and the vulnerability of the fetus, women who are pregnant should not participate in MR studies.

“You have stated that you are not pregnant, however women are frequently not aware that they are pregnant in the first trimester of pregnancy. If you do not know if you are pregnant and would like to check, free pregnancy tests are available from the researcher. You can withdraw from the study at any time, without penalty.”

COUHES acknowledges that screening females under 18 raises additional concerns. The researcher should therefore balance the likelihood of pregnancy with possible intrusion into the parent-daughter relationship that aggressive screening may bring. Options include mentioning pregnancy as a reason not to participate at the time of recruitment or verbal screening. Assent forms should include information on what will be done with the results of screening, and caution should be used to avoid accidental disclosures of pregnancy to anyone other than the subject.