A special issue of the American Journal of Medical Genetics Part C with a specific focus on teratology―or the study of birth defects and their causes―recently has been published online. Included in this special issue is a new CDC study: “Influencing Clinical Practice Regarding the Use of Antiepileptic Medications During Pregnancy: Modeling the Potential Impact on the Prevalences of Spina Bifida and Cleft Palate in the United States.” You can read the abstract here. Following is a summary of the findings from this article.
About antiepileptic medications and this study
Emerging Issues in Teratology
An introductory editorial article co-written by a CDC author is also in the special issue of this journal. This article gives a brief historical overview of the study of birth defects. It also highlights emerging topics that are discussed in the special issue.
Epilepsy is a disorder in which individuals have repeated seizures. Epilepsy, and sometimes other diseases such as chronic headaches and bipolar disorder, can be treated with antiepileptic medications, such as valproic acid and carbamazepine. Pregnant women need treatment for epilepsy because it is possible that seizures can cause adverse health outcomes for the mother and her developing baby. However, previous studies consistently have found that babies born to women who take certain antiepileptic medications during pregnancy have an increased risk for birth defects.
Studies have shown that valproic acid presents the most risk to the developing baby. Along with valproic acid, carbamazepine might increase the risk for spina bifida (a major birth defect of the baby’s spine) and cleft palate (a birth defect of the baby’s mouth).
For this study, researchers estimated how many babies could be born each year without spina bifida and cleft palate if all women who needed treatment with valproic acid or carbamazepine were switched to lower risk medications during pregnancy. Prevention of even a few major birth defects could have a major public health impact, given the disabilities and costs associated with birth defects. 1-5
Main findings from this study
- About 40 infants with spina bifida and about 35 infants with cleft palate could be born without these defects each year in the United States if valproic acid were not used during pregnancy.
- About 5 infants with spina bifida and about 5 infants with cleft palate could be born without these defects each year in the United States if carbamazepine were not used during pregnancy.
This study demonstrates the potential public health impact if doctors were to switch women of childbearing age who need treatment with certain antiepileptic medications to lower risk medications when possible.
When making treatment decisions just before or during pregnancy, it is important that women and their doctors weigh the benefits of antiepileptic medication treatment along with the potential risks for both the woman and her unborn baby.
Medication use during pregnancy: CDC activities
The Centers for Disease Control and Prevention (CDC) is committed to working with its partners and the public to build a comprehensive approach to understanding and communicating the risks of birth defects that potentially are associated with the use of medications during pregnancy.
- Research: CDC funds a large study of birth defects called the National Birth Defects Prevention Study. This study is working to identify risk factors for birth defects and to answer questions about some medications taken during pregnancy.
- Technical expertise: CDC works with the U.S. Food and Drug Administration, drug manufacturers, and other professionals to help conduct studies on the effects of medication use during pregnancy and ways to prevent harmful effects.
Learn more about medication use during pregnancy »
Learn more about birth defects »
- CDC. Hospital stays, hospital charges, and in-hospital deaths among infants with selected birth defects, United States, 2003. MMWR 2007;56:25-29.
- Ouyang L, Grosse SD, Armour BS, Waitzman NJ. Health care expenditures of children and adults with spina bifida in a privately insured U.S. population. Birth Defects Res A Clin Mol Teratol. 2007;79:552-8.
- Cassell CH, Meyer R, Daniels J. Health care expenditures among Medicaid enrolled children with and without orofacial clefts in North Carolina, 1995-2002. Birth Defects Res A Clin Mol Teratol. 2008;82:785–94.
- Weiss J, Kotelchuck M, Grosse S, Manning SE, Anderka M, Wyszynski DF. Hospital use and associated costs of children ages zero-to-two years with craniofacial malformations in Massachusetts. Birth Defects Res A Clin Mol Teratol. 2009;85:925–34.
- Boulet SL, Grosse SD, Honein MA, Correa-Villaseñor, A. Children with orofacial clefts: health care use and costs among a privately insured population. Public Health Rep. 2009;124:447–53.
Reference for Key Findings Summary
Gilboa SM, Broussard CS, Devine OJ, Duwe KN, Flak AL, Boulet SL, Moore CA, Werler MM, and Honein MA. Influencing Clinical Practice Regarding the Use of Antiepileptic Medications During Pregnancy: Modeling the Potential Impact on the Prevalences of Spina Bifida and Cleft Palate in the United States. Am J Med Genet Part C [E-pub ahead of print].