Teratogenic drug use: Check contraception
Executive Summary
About 1.7 million women of childbearing age are prescribed Food and Drug Administration Category D or Category X medications each year. However, despite label warnings, about 6% of U.S. pregnancies occur in women taking medications with known teratogenic risk.
• The most commonly prescribed Category D and X drugs in the primary care setting are anxiolytics, anticonvulsants, antibiotics, and statins; 45% of such prescriptions are written by family physicians or internal medicine physicians.
• Patients might not receive detailed counseling about the potential birth defects associated with certain medications and the importance of using highly effective contraception
About 1.7 million women of childbearing age are prescribed Food and Drug Administration (FDA) Category D or Category X medications each year. Despite label warnings, about 6% of U.S. pregnancies occur in women taking medications with known teratogenic risk.1,2 According to the FDA, Category D includes those drugs with which "adequate studies in pregnant women have shown evidence of fetal harm, but potential benefits may outweigh risk," while Category X encompasses drugs in which "adequate studies in pregnant women have shown evidence of fetal harm; contraindicated in women who are or may become pregnant."3
The most commonly prescribed Category D and X drugs in the primary care setting are anxiolytics, anticonvulsants, antibiotics, and statins; 45% of such prescriptions are written by family physicians or internal medicine physicians.1 In a study of 488,175 women ages 15-44 enrolled in a large, northern California health maintenance organization (HMO), researchers identified 1.01 million filled prescriptions for class A, B, D, or X drugs.4 In this study, one of every six women filled a class D or X prescription. Researchers found these women were no more likely than women who filled prescriptions for safer class A or B medications to have received contraceptive counseling, filled a contraceptive prescription, or undergone a sterilization procedure.
Patients might not receive detailed counseling about the potential birth defects associated with certain medications and the importance of using highly effective contraception, says Sheila Mody, MD, MPH, FACOG, assistant professor and women’s reproductive health research (k12) scholar in the Department of Reproductive Medicine at the University of California, San Diego. Mody and fellow researchers have conducted a pilot research study to assess the feasibility of an electronic medical record alert/referral to teratogen and contraceptive counseling for women seen in family medicine taking a category D or X medication.
The research team has discovered that many of these women were using the least effective contraceptive methods, says Mody. They also have found that after teratogen and contraceptive counseling, about one-third of participants were willing to use more effective contraception.
"An intervention to improve teratogen and contraceptive counseling is one of the few ways we can potentially decrease the number of pregnancies exposed to teratogens," says Mody.
Have the conversation
While family planning clinicians are well-versed in discussing effective birth control methods, other providers might be less educated. Surveys of medical schools, residents, and physicians show that training in contraceptive counseling and provision is insufficient.5,6
Talking about contraception and teratogenic drugs requires a "careful conversation," says Eleanor Bimla Schwarz, MD, MS, director of the women’s health services research unit at the Center for Research on Health Care in the University of Pittsburgh School of Medicine. Some women must take medications to treat health conditions such as asthma, epilepsy, hypertension, or depression, and they might need to continue to take medication to stay healthy during pregnancy. If such conditions are not treated, a pregnant woman or her unborn baby could be harmed.
One way that may help providers identify patients who need preconception or contraceptive counseling, especially when teratogenic medications are prescribed, is through a "contraceptive vital sign," a routine assessment of women’s pregnancy intentions and contraceptive use.
Schwarz and fellow researchers randomly assigned 26 physicians from a large academic internal medicine practice to an intervention group that added the contraceptive vital sign questions to the intake questionnaire. They randomly assigned another 27 physicians from the practice to a control group that used an intake form with standard questions. During the study period, there were 816 visits to intervention physicians during which they asked the contraceptive vital sign questions, with answers provided by 93% of the women; 7% of the women did not answer the questions or did not finish the questionnaire.
Intervention physicians were notified by the electronic health record’s decision support software to "consider chance of pregnancy when prescribing" in 110 visits (13.5%). For visits involving a potentially teratogenic prescription, documentation of contraception for women visiting intervention-cluster physicians rose from 14.1% at baseline to 72.9% during the study period. For women visiting control physicians, 26.6% had medical record documentation of contraception at baseline versus 25.5% during the study period.7
In this same study, provision of new family planning services were increased only minimally with this intervention. When women with documented nonuse of contraception were prescribed potential teratogens, only 7% were provided family planning services.7
"A contraceptive vital sign improves documentation of contraceptive use; however, ongoing efforts are needed to improve provision of preconception and contraceptive services," researchers conclude.
- Schwarz EB, Maselli J, Norton M, et al. Prescription of teratogenic medications in United States ambulatory practices. Am J Med 2005; 118(11):1,240-1,249.
- Andrade SE, Gurwitz JH, Davis RL, et al. Prescription drug use in pregnancy. Am J Obstet Gynecol 2004; 191(2),398-407.
- Food and Drug Administration. Code of Federal Regulations. Accessed at http://1.usa.gov/1hlyuH0.
- Schwarz EB, Postlethwaite DA, Hung YY, et al. Documentation of contraception and pregnancy when prescribing potentially teratogenic medications for reproductive-age women. Ann Intern Med 2007; 147(6):370-376.
- Steinauer J, LaRochelle F, Rowh M, et al. First impressions: what are preclinical medical students in the US and Canada learning about sexual and reproductive health? Contraception 2009; 80:74-80.
- Eisenberg DL, Stika C, Desai A, et al. Providing contraception for women taking potentially teratogenic medications: a survey of internal medicine physicians’ knowledge, attitudes and barriers. J Gen Intern Med 2010; 25:291-297.
- Schwarz EB, Parisi SM, Williams SL, et al. Promoting safe prescribing in primary care with a contraceptive vital sign: a cluster-randomized controlled trial. Ann Fam Med 2012; 10(6):516-522.
