Julianne S. Collins

Updated National Birth Prevalence estimates for selected birth defects in the United States, 2004-2006.

BACKGROUNDnThe National Birth Defects Prevention Network collects state-specific birth defects surveillance data for annual publication of prevalence estimates and collaborative research projects. In 2006, data for 21 birth defects from 1999 through 2001 were presented as national birth prevalence estimates. The purpose of this report was to update these estimates using data from 2004 through 2006.nnnMETHODSnPopulation-based data from 11 active case-finding programs, 6 passive case-finding programs with case confirmation, and 7 passive programs without case confirmation were used in this analysis. Pooled birth prevalence estimates for 21 birth defects, stratified by case ascertainment approach, were calculated. National prevalence estimates, adjusted for maternal race/ethnicity and maternal age (trisomy 13, trisomy 18, and Down syndrome only) were determined using data from 14 programs. The impact of pregnancy outcomes on prevalence estimates was also assessed for five specific defects.nnnRESULTSnNational birth defects prevalence estimates ranged from 0.72 per 10,000 live births for common truncus to 14.47 per 10,000 live births for Down syndrome. Stratification by type of surveillance system showed that active programs had a higher prevalence of anencephaly, anophthalmia/microphthalmia, cleft lip with or without cleft palate, reduction defect of upper limbs, and trisomy 18. The birth prevalence of anencephaly, trisomy 13, and trisomy 18 also varied substantially with inclusion of elective terminations.nnnCONCLUSIONnAccurate and timely national estimates of the prevalence of birth defects are needed for monitoring trends, assessing prevention efforts, determining service planning, and understanding the burden of disease due to birth defects in the United States.

SURVIVAL OF INFANTS WITH NEURAL TUBE DEFECTS IN THE PRESENCE OF FOLIC ACID FORTIFICATION

OBJECTIVE. Neural tube defects (NTDs) are preventable through preconceptional and periconceptional folic acid intake. Although decreases in the prevalence of NTDs have been reported since folic acid fortification of United States grain products began, it is not known whether folic acid plays a role in reducing the severity of occurring NTDs. Our aim was to determine whether survival among infants born with spina bifida and encephalocele has improved since folic acid fortification and to measure the effects of selected maternal, pregnancy, and birth characteristics on first-year (infant) survival rates. METHODS. A retrospective cohort study was conducted and included 2841 infants with spina bifida and 638 infants with encephalocele who were born between 1995 and 2001 and were registered in any of 16 participating birth defects monitoring programs in the United States. First-year survival rates for both spina bifida and encephalocele cohorts were measured with Kaplan-Meier estimation; factors associated with improved chances of first-year survival, including birth before or during folic acid fortification, were measured with Cox proportional-hazards regression analysis. RESULTS. Infants with spina bifida experienced a significantly improved first-year survival rate of 92.1% (adjusted hazard ratio: 0.68; 95% confidence interval: 0.50–0.91) during the period of mandatory folic acid fortification, compared with a 90.3% survival rate for those born before fortification. Infants with encephalocele had a statistically nonsignificant increase in survival rates, ie, 79.1% (adjusted hazard ratio: 0.76; 95% confidence interval: 0.51–1.13) with folic acid fortification, compared with 75.7% for earlier births. CONCLUSIONS. Folic acid may play a role in reducing the severity of NTDs in addition to preventing the occurrence of NTDs. This phenomenon contributes to our understanding of the efficacy of folic acid. Additionally, as survival of NTD-affected infants improves, health care, education, and family support must expand to meet their needs.

Public health projects for preventing the recurrence of neural tube defects in the United States

BACKGROUNDnThe recurrence risk for neural tube defects (NTDs) in subsequent pregnancies is approximately 3%, or 40 times the background risk. Prevention projects target these high-risk women to increase their folic acid consumption during the periconceptional period, a behavior which decreases their recurrence risk by at least 85%. This study surveyed birth defect surveillance programs to assess their NTD recurrence prevention activities and to identify components of intervention projects that might be implemented in states with limited resources.nnnMETHODSnIn 2005, the National Birth Defects Prevention Network developed and distributed an online survey to primary state birth defects surveillance contacts for the purpose of gathering information on NTD recurrence prevention activities in the United States.nnnRESULTSnResponses came from 37 contacts in 34 states and Puerto Rico. There were 13 active NTD recurrence prevention projects, four past projects, and three planned projects. Fifteen past and present projects recommended that women with a prior NTD-affected birth take 4.0 mg of folic acid daily, and four projects provided folic acid to the women. Reasons given for not having an NTD recurrence prevention project included staffing limitations (53%), lack of funds (47%), lack of priority (18%), and confidentiality/privacy concerns (6%).nnnCONCLUSIONSnOnly 15 states and Puerto Rico had or were planning NTD recurrence prevention projects. An NTD recurrence prevention project using minimal resources should consist of timely case ascertainment, educational materials, and mechanisms for disseminating these materials.

Advancing the science of birth defects surveillance, epidemiology, and prevention

In the November 2008 issue of Birth Defects Research Part A (BDRA), we present 11 original articles as well as an editorial on the epidemiological and methodological studies of birth defects. This issue and the December 2008 issue of BDRA constitute the 10th annual report of the National Birth Defects Prevention Network (NBDPN). The NBDPN remains committed to the primary prevention of birth defects and improvement of outcomes for children and families living with birth defects through the use of birth defects surveillance data for research, program planning, and program evaluation. It is our hope that the methods and findings from these articles will contribute to the continual improvement of the science and practice of birth defects surveillance and prevention in the United States and around the globe. The December 2008 issue provides a national perspective on state-level prevalences of specific birth defects in the United States. Collectively, the two issues of BDRA that constitute the NBDPN annual report highlight the progress made in applying birth defects surveillance data to our understanding of the epidemiology and public health significance of birth defects in the United States. We are honored to include a thought-provoking editorial by Godfrey Oakley and Robert Brent on birth defects prevention in this issue of BDRA. We then present two articles focused on neural tube defects. Shin, Besser, and Correa examine the prevalence of spina bifida among children and adolescents, while Carmichael et al. examine variation in the prevalence of neural tube defects among different Hispanic subgroups. Results of both studies have implications for the design of prevention programs and public health services. A study from Texas by Wang et al. examines the prevalence of infantile hypertrophic pyloric stenosis, a defect occurring more commonly in white males. We are also pleased to include two studies which examine the effect of maternal smoking on the risk of birth defects. Feldkamp, Alder, and Carey examine whether smoking is associated with gastroschisis, while Wong-Gibbons et al. examine whether periconceptional exposure to alcohol and smoking is associated with esophageal atresia with or without tracheo-esophageal fistula. Two studies apply health services research methods to understanding issues with costs and access to services for children with birth defects. The article on the health care costs of children with orofacial clefts by Cassell, Meyer, and Daniels contributes to an emerging literature on health care costs in special needs children, and may be useful in program planning and policy development. Case et al. studied the proximity of pediatric genetic services to children with birth defects in Texas, identifying regional variation in accessibility to these services which may be instrumental in changing the distribution of clinical geneticists in Texas and encouraging other state programs to perform similar assessments. The issue concludes with four methodological articles that we hope will help surveillance programs expand and improve their activities. Duke, Williams, and Correa discuss how to improve surveillance data on stillbirths, while Kucik et al. describe a formal process for analyzing and pooling information from birth defect cluster investigations. Mason and Tu provide a very useful primer on data linkage using probabilistic decision rules, and Jurczyk et al. describe a software tool, FRIL, that can provide data linkage for surveillance programs. The articles included in the November 2008 issue were selected from those submitted in response to a call for manuscripts distributed to all state birth defect surveillance programs, NBDPN members, the birth defects surveillance list serv, and posted on the NBDPN website (http://www.nbdpn.org). The papers included here underwent both editorial board and formal blinded peer review. The review process was facilitated by the use of the online peer-review management system provided by Wiley for the BDRA editors. As with many collaborative enterprises, many dedicated individuals contributed their time and effort to ensure the quality of the NBDPN annual report. These include the following peer reviewers of manuscripts: Derek Chapman, Julianne Collins, Jean Connor, Glenn Copeland, Andrew Czeizel, Jane Evans, Marcia Feldkamp, Tim Flood, Alina Flores, Violanda Grigorescu, Scott Grosse, Katie Hutchinson, Russell Kirby, James Kucik, Peter Langlois, Craig Mason, Bob Meyer, Russel Rickard, Gary Shaw, Csaba Siffel, Matthew Strickland, Lucina Suarez, Daniel Wartenberg, and Martha Werler. We also thank the many members of the NBDPN Data and Publications and Communications Committees. We thank Diana Juriloff for her tireless help and patience in facilitating the review and publication of these manuscripts. We also thank Kevin Jeannette and Michael