Search

Birth defects are an urgent global health priority. They affect millions of births worldwide. But their prevalence and impact are largely under-ascertained, particularly in middle- and low-income countries. Fortunately, a large proportion of birth defects can be prevented. This review examines the global prevalence and primary prevention methods for major preventable birth defects: congenital rubella syndrome, folic acid-preventable spina bifida and anencephaly, fetal alcohol syndrome, Down syndrome, rhesus hemolytic disease of the fetus and the newborn; and those associated with maternal diabetes, and maternal exposure to valproic acid or iodine deficiency during pregnancy. Challenges to prevention efforts are reviewed. The aim of this review is to bring to the forefront the urgency of birth defects prevention, surveillance, and prenatal screening and counseling; and to help public health practitioners develop population-based birth defects surveillance and prevention programs, and policy-makers to develop and implement science-based public health policies., (Copyright © 2013. Published by Elsevier Ltd.)

Background: Scientific evidence has consistently shown taking valproate during pregnancy increases risks of congenital malformations and cognitive impairment. As such, elimination of its use would be an important step in birth defects prevention. There are guidelines discouraging its use among women with epilepsy, but none exists for women without epilepsy, nor is the prevalence of valproate for nonepilepsy indications known., Methods: Using de-identified data from the National Hospital and Ambulatory Medical Care Surveys (1996-2007), we examined individual prescriptions for reproductive-age adolescent girls and adult women ages 15 to 44 years in the United States, and estimated the number of antiepileptic drug and valproate prescriptions in the aggregate. We classified our study population using International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes, as women with epilepsy and women without epilepsy. The prevalence of antiepileptic drug and valproate prescriptions among women without epilepsy was estimated as prescriptions per 1000 patient visits for every 3-year time interval and the overall study period., Results: We found 83% of valproate prescriptions were issued to women without epilepsy and 74% of these were for psychiatric diagnoses. The prevalence of antiepileptic drug prescriptions among women without epilepsy tripled during the study period (10.3 [1996-1998] vs. 34.9 [2005-2007] per 1000 patient visits), whereas valproate prescriptions remained relatively stable (3.1 [1996-1998] vs. 3.7 [2005-2007] per 1000 patient visits)., Conclusion: Most women of reproductive age who receive a valproate prescription do not have epilepsy. Valproate prescriptions did not decline, despite increasing knowledge of its teratogenicity. Reducing valproate use among women of reproductive age, especially among those who use the drug for psychiatric indications, would prevent birth defects and cognitive deficits., (Copyright © 2013 Wiley Periodicals, Inc.)

The incidence of selected congenital malformations in areas with fluoride supplementation of public water supplies was compared with the incidence in areas where the water supply is deficient in fluoride. Comparison of the incidences of several common birth defects (including Down's syndrome) in fluoridated and nonfluoridated areas revealed no substantial or significant differences in which there was a consistent pattern for both sets of data.

As part of its epidemiologic studies of congenital malformations, the Centers for Disease Control (CDC) conducts two birth defects surveillance systems in the United States. The Metropolitan Atlanta Congenital Defects Programme (MACDP) is an intensive surveillance system using several methods to identify infants born with birth defects in the Atlanta area. The Birth Defects Monitoring Programme (BDMP) is a nationwide surveillance system that monitors 1 million births per year, about a third of all births in the U.S. It relies on diagnoses from newborn discharge summaries to ascertain affected infants. The systems were originally designed to detect potential 'epidemics' of birth defects that could occur following the widespread dissemination of new teratogens similar to thalidomide. In addition to monitoring, they have also proved to be useful resources for a variety of studies of the epidemiology of birth defects.

Birth defects are important health problems. They are the leading cause of infant mortality, the fifth leading cause of premature years of life lost, and important contributors to our nation's chronic disease burden. Researchers have been successful in finding a few causes of birth defects; however, the etiology of the majority of birth defects remains unknown and thus hampers our ability to prevent these diseases. Clinicians who care for patients with birth defects can play an important role in etiologic research by developing good and testable etiologic hypotheses. Epidemiologists must then use these hypotheses and those provided by scientists working with experimental animals to design studies that can test these hypotheses.

An important national health goal is to reduce morbidity attributable to birth defects and developmental disabilities. Population-based surveillance has made notable contributions toward preventing these problems; it is also useful in monitoring changes in their incidence and in helping to identify reproductive hazards in the environment. The Metropolitan Atlanta Congenital Defects Program of the Centers for Disease Control is a model for such surveillance activities. Its register contains data on birth defects of all infants born in the five-county metropolitan area since 1976. Information on all major malformations discernible by physical examination is collected by the register staff. Mothers of babies with selected major malformations are interviewed at length. The register data base permits testing of new hypotheses concerning birth defects. It has speeded an extensive study of the possible effects of military service in Vietnam on the risk of having a baby with a birth defect. In addition, because of their special skills, program staff have made contributions to genetic services and to the development of national policy on maternal serum alpha fetoprotein.