By Lynn Martinez and Julia Robertson, CPM
In the more than 40 years that MotherToBaby affiliates have been serving the public with education about exposures during pregnancy, many women have called in very distressed, sometimes in tears, to discover they were pregnant while taking a drug categorized as X or D the Food and Drug Administration (FDA) system. “I was on birth control pills and still got pregnant! Does this mean my baby will have birth defects? It’s class X drug for good!’ This kind of hysterical reaction was, unfortunately, a common appeal. It was not uncommon to hear that some of these women had considered terminating otherwise desirable pregnancies. The FDA realized that these pregnancy categories weren’t as useful as they wanted and stopped using them in 2014, about ten years ago. They now use the Pregnancy and Lactation Labeling Rule (PLLR) which has a drug narrative summary, similar to what you’ll find here on MotherToBaby.
But first, a little background…
For decades the FDA has been aware of significant problems with the system used to categorize drugs for use in pregnancy. In 1992, the Teratology Society (now known as the Society for Birth Defects Research and Prevention), an interdisciplinary group of scientists who study birth defects, raised concerns and noted that the Category or “CAT” system led to unnecessary terminations of desired pregnancies1. The FDA’s Pregnancy Labeling Initiative recommended eliminating the CAT system, changing the label to include more descriptive risk statements, and requiring drug inserts to be updated when human information is known.
Before the labeling rule changed, when a drug was approved for sale in the U.S., it had to be labeled with one of five pregnancy GATs: A, B, C, D, or X. A meant the drug was well studied and did not pose a threat to a developing baby; B was a less studied but probably still low-risk drug. C was an unstudied drug and therefore the risk was unknown. a class D drug, based on animal or human data, may have posed a risk; and classification X meant that the drug, based on animal or human data, caused birth defects or there was no benefit from its use during of pregnancy. Its use is not recommended during pregnancy.
More than 90 percent of new drugs were categorized as CAT C, D or X, with the vast majority being C. Drug manufacturers were legally required to update the category if harmful effects were reported. However, there was no such requirement to inform the category when the studies showed no problems in pregnancy. Most drugs on the market in 2014 were classified as CAT C, when in fact the majority should have been labeled as CAT A or B. Manufacturers knew that regardless of a woman’s history, all pregnancies carry a 3 percent risk of stillbirth with a serious genetic defect. Because of this, many manufacturers may have felt better protected from lawsuits if their drugs were listed as CAT C, D, or X. So, really, why move drugs in those categories to A or B? They really had no motivation.
Moving forward and what it means for mom…
With the FDA rule change in 2014, a new set of requirements was put into place to better inform mom. It now requires manufacturers to “update” a drug’s labeling when studies show the risk has changed. Also, manufacturers should explore different ways to discuss in detail the risks associated with the drug. One resource of experts that manufacturers could consult is a teratogen information service such as MotherToBaby. More information will help you make more informed choices about your health and pregnancy!
There will still be confusion…
As we see the new labels implemented, there will still be many drugs on the market with the CAT system as it will take time to update them all. MotherToBaby does not recommend that the public or providers rely on the old CAT system for risk assessment. We welcome your questions about the system as well as questions about specific drugs in pregnancy and breastfeeding for a complete, individualized risk assessment. Call us TOLL FREE at 866-626-6847.
Lynn Martinez is a retired Teratogen Information Specialist. Lynn has traveled Utah training physicians, nurse midwives, pharmacists and others for the past three decades.
Julia Robertson, CPM, now retired, works part-time overseeing quality control efforts for MotherToBaby. In her 25-year career as a teratogen information specialist, she authored several peer-reviewed publications focusing on maternal drug consumption and the effect on the developing fetus.
MotherToBaby is a service of the International Organization for Special Teratology Information (OTIS), a recommended resource by many agencies, including the Centers for Disease Control and Prevention (CDC). If you have questions about medications, alcohol, diseases, vaccines, or other exposures during pregnancy or breastfeeding, call MotherToBaby TOLL FREE at 866-626-6847 or visit a library newsletters.
