Findings from a 15-year study suggest that there might be poor adherence to Canada’s pregnancy prevention program among women taking oral isotretinoin for the treatment of acne, researchers reported online in the Canadian Medical Association Journal (Apr. 25, 2016).
The authors reported that Canada’s pregnancy prevention program recommends informed written consent, two negative pregnancy tests before beginning isotretinoin treatment and the use of two reliable birth control methods during isotretinoin treatment.
During the study the researchers looked at anonymized patient records for 59,271 women taking isotretinoin aged 12 to 48 years in four Canadian provinces—British Columbia, Saskatchewan, Manitoba and Ontario—between 1996 and 2011.
Data revealed that over the 15-year study period, there were 1,473 pregnancies, 118 (8%) of which resulted in live births. Of those, 11 (9%) were identified as having congenital abnormalities.
Pregnancy rates during isotretinoin treatment ranged from 4 to 6/1,000 users. The at-risk period for exposure extends beyond the end of treatment, and overall pregnancy rates including this later period were higher.
Of the women taking isotretinoin, 30% to 50% do not comply with the program’s requirements, which given the severe harm the drug can cause to a fetus, represents poor performance of the pregnancy prevention program.
“Poor adherence with the Canadian pregnancy prevention guidelines means that Canada, inadvertently, is using pregnancy termination rather than pregnancy prevention to manage fetal risk from isotretinoin,” states lead author David Henry, senior scientist at the Institute for Clinical Evaluative Sciences at Sunnybrook Health Sciences Centre In Toronto.
Despite the recommendations that women take strict precautions to prevent pregnancy while taking isotretinoin, the researchers found that only one-quarter to one-third of women filled birth control prescriptions while taking isotretinoin, nearly identical to rates in the previous 12 months. However, the researchers note that they were not able to track the use of birth control pills obtained without plan coverage (perhaps from a free clinic) or directly from a supply from a doctor, or the use of intrauterine devices or barrier methods.
Numerous studies in Canada and internationally have indicated poor adherence to pregnancy prevention guidelines among women taking isotretinoin.
Findings would suggest that “It appears that not all doctors and patients are sticking closely to the guidelines to prevent pregnancy during treatment with isotretinoin,” added Henry, who was quoted in a press release.
“It is clear from this experience and from studies in Europe that modifying contraceptive behaviour in this setting is difficult,” said Brandace Winquist, PhD, a coauthor of the study from the University of British Columbia.
“Nevertheless, medical practitioners and patients must be constantly reminded of the risks of isotretinoin to the fetus and implement effective contraceptive measures,” said Dr. Winquist.