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Background Congenital microcephaly has been linked to maternal Zika virus infection. However, ascertaining infants diagnosed with microcephaly can be challenging. Methods Thirty birth defects surveillance programs provided data on infants diagnosed with microcephaly born 2009 to 2013. The pooled prevalence of microcephaly per 10,000 live births was estimated overall and by maternal/infant characteristics. Variation in prevalence was examined across case finding methods. Nine programs provided data on head circumference and conditions potentially contributing to microcephaly. Results The pooled prevalence of microcephaly was 8.7 per 10,000 live births. Median prevalence (per 10,000 live births) was similar among programs using active (6.7) and passive (6.6) methods; the interdecile range of prevalence estimates was wider among programs using passive methods for all race/ethnicity categories except Hispanic. Prevalence (per 10,000 live births) was lowest among non-Hispanic Whites (6.5) and highest among non-Hispanic Blacks and Hispanics (11.2 and 11.9, respectively); estimates followed a U-shaped distribution by maternal age with the highest prevalence among mothers

Background Geographic variation in congenital heart disease is not well-described. This study uses geographic information systems (GIS) to describe the spatial epidemiology of tetralogy of Fallot (TOF), in North Carolina (NC) and to compare travel time for cases to congenital heart centers in NC. Methods Using the NC Birth Defects Monitoring Program database, live births with TOF born between 2003 and 2012 were identified. Birth certificates provided demographic variables. A denominator of live births/zip code was obtained from the NC live births database. ArcGIS® software was used to illustrate TOF prevalence by zip code, and SatScanTM was used to identify spatial clusters of TOF cases and to identify changes in cluster location over time. Driving time to each of five NC congenital heart centers was predicted based on road systems information. Results A total of 496 infants were born with TOF between 2003 and 2012. The prevalence was 4.2/10,000 live births. A large cluster (330 zip codes, 306 cases) was identified in northeastern NC. Average driving time for each case to closest congenital heart center was: University of North Carolina 37 min, Vident Medical Center 64 min, Duke University 58 min, Carolina's Medical Center 89 min, and Wake Forest Baptist Health 57 min. Overall, average predicted driving time to the nearest congenital heart center was 61 min. Conclusion Approximately 50 infants/year were born with TOF in NC. One cluster was identified. Further study is necessary to explore potential explanations for the observed case cluster. As interest in regionalization of congenital heart surgery grows, GIS and spatial analysis can become increasingly useful tools for health care planning. Birth Defects Research (Part A) 106:881-887, 2016. © 2016 Wiley Periodicals, Inc.

Background Birth defects are responsible for a large proportion of disability and infant mortality. Exposure to a variety of pesticides have been linked to increased risk of birth defects. Methods We conducted a case–control study to estimate the associations between a residence-based metric of agricultural pesticide exposure and birth defects. We linked singleton live birth records for 2003 to 2005 from the North Carolina (NC) State Center for Health Statistics to data from the NC Birth Defects Monitoring Program. Included women had residence at delivery inside NC and infants with gestational ages from 20 to 44 weeks (n = 304,906). Pesticide exposure was assigned using a previously constructed metric, estimating total chemical exposure (pounds of active ingredient) based on crops within 500 meters of maternal residence, specific dates of pregnancy, and chemical application dates based on the planting/harvesting dates of each crop. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals for four categories of exposure ( 90th percentiles) compared with unexposed. Models were adjusted for maternal race, age at delivery, education, marital status, and smoking status. Results We observed elevated ORs for congenital heart defects and certain structural defects affecting the gastrointestinal, genitourinary and musculoskeletal systems (e.g., OR [95% confidence interval] [highest exposure vs. unexposed] for tracheal esophageal fistula/esophageal atresia = 1.98 [0.69, 5.66], and OR for atrial septal defects: 1.70 [1.34, 2.14]). Conclusion Our results provide some evidence of associations between residential exposure to agricultural pesticides and several birth defects phenotypes. Birth Defects Research (Part A) 106:240–249, 2016. © 2016 Wiley Periodicals, Inc.

Background: Epidemiologic studies involving birth defects are extremely sensitive to phenotype accuracy and precision. We devised a case review and classification protocol for a project to study school achievement in children with idiopathic, nonsyndromic orofacial clefts to improve the reliability of phenotypic classification from the statewide birth defects registry. Methods: Surveillance-program abstraction data and medical records at the birth or treating hospitals were used when available. Exclusion criteria included: median cleft lip; Tessier cleft; premaxillary agenesis; presence of a recognizable syndrome, phenotype, association, or sequence (other than Robin sequence); clefts with other malformations not considered to be normal or common variants in the newborn; and cases with documented or suspected genetic or teratogenic causes. Results: Of 712 children identified with orofacial clefts, 153 were excluded, leaving 559 nonsyndromic orofacial cleft cases of unknown cause in the final study. These cases were grouped into the following clinically meaningful types: cleft lip with or without cleft alveolus; cleft lip and cleft palate; and cleft palate only. This review and classification process resulted in the elimination of 21.5% of the original cohort of identified cases, with most exclusions being due to suspected syndromic associations. Conclusion: Verbatim descriptions of the clinical findings are critical for accurate classification of diagnoses. This review process improved the precision of orofacial cleft phenotype classification for our study. Precision would have been further improved if all of the cases had verbatim descriptions of diagnoses and all medical records could have been reviewed by the classification team. Birth Defects Research (Part A) 103:899–903, 2015. © 2015 Wiley Periodicals, Inc.

BACKGROUND Nonresponse bias assessment is an important and underutilized tool in survey research to assess potential bias due to incomplete participation. This study illustrates a nonresponse bias sensitivity assessment using a survey on perceived barriers to care for children with orofacial clefts in North Carolina. METHODS Children born in North Carolina between 2001 and 2004 with an orofacial cleft were eligible for inclusion. Vital statistics data, including maternal and child characteristics, were available on all eligible subjects. Missing ‘responses’ from nonparticipants were imputed using assumptions based on the distribution of responses, survey method (mail or phone), and participant maternal demographics. RESULTS Overall, 245 of 475 subjects (51.6%) responded to either a mail or phone survey. Cost as a barrier to care was reported by 25.0% of participants. When stratified by survey type, 28.3% of mail respondents and 17.2% of phone respondents reported cost as a barrier. Under various assumptions, the bias-adjusted estimated prevalence of cost as barrier to care ranged from 16.1% to 30.0%. Maternal age, education, race, and marital status at time of birth were not associated with subjects reporting cost as a barrier. CONCLUSION As survey response rates continue to decline, the importance of assessing the potential impact of nonresponse bias has become more critical. Birth defects research is particularly conducive to nonresponse bias analysis, especially when birth defect registries and birth certificate records are used. Future birth defect studies which use population-based surveillance data and have incomplete participation could benefit from this type of nonresponse bias assessment. Birth Defects Research (Part A) 103:603–609, 2015. © 2015 Wiley Periodicals, Inc.

Background The Birth Defects Study To Evaluate Pregnancy exposureS (BD-STEPS) is a population-based, multi-Center case-control study of modifiable risk factors for selected birth defects in the United States. BD-STEPS is the second major research effort of the Centers for Birth Defects Research and Prevention, which extends and expands the initial research effort, the National Birth Defects Prevention Study (NBDPS).

© 2014 The Authors Birth Defects Research Part A: Clinical and Molecular Teratology Published by Wiley Periodicals, Inc.

Background Little is known about the barriers faced by families of children with birth defects in obtaining healthcare. We examined reported perceived barriers to care and satisfaction with care among mothers of children with orofacial clefts.

BACKGROUND Information on travel distance and time to care for children with birth defects is lacking. We examined factors associated with travel distance and time to cleft care among children with orofacial clefts. METHODS In 2006, a mail/phone survey was administered in English and Spanish to all resident mothers of children with orofacial clefts born 2001 to 2004 and identified by the North Carolina birth defects registry. We analyzed one-way travel distance and time and the extent to which taking a child to care was a problem. We used multivariable logistic regression to examine the association between selected sociodemographic factors and travel distance (≤60 miles and >60 miles) and time (≤60 min and >60 min) to cleft care. RESULTS Of 475 eligible participants, 51.6% (n = 245) responded. Of the respondents, 97.1% (n = 238) were the child's biological mother. Approximately 83% (n = 204) of respondents were non-Hispanic White; 33.3% (n = 81) were college educated; and 50.0% (n = 115) had private health insurance. One-way mean and median travel distances were 80 and 50 miles, respectively (range, 0–1058 miles). One-way mean and median travel times were 92 and 60 min, respectively (range, 5 min to 8 hr). After adjusting for selected sociodemographics, travel distance varied significantly by maternal education, child's age, and cleft type. Travel time varied significantly by child's age. Approximately 67% (n = 162) reported taking their child to receive care was not a problem. CONCLUSION Approximately 48% of respondents traveled > 1 hr to receive cleft care. Increasing access to care may be important for improving health outcomes among this population Birth Defects Research (Part A) 97:685–695, 2013. © 2013 Wiley Periodicals, Inc.

BACKGROUND Few studies have examined the potential relationship between air pollution and birth defects. The objective of this study was to investigate whether maternal exposure to particulate matter (PM2.5) and ozone (O3) during pregnancy is associated with birth defects among women living throughout North Carolina. METHODS Information on maternal and infant characteristics was obtained from North Carolina birth certificates and health service data (2003–2005) and linked with information on birth defects from the North Carolina Birth Defects Monitoring Program. The 24-hr PM2.5 and O3 concentrations were estimated using a hierarchical Bayesian model of air pollution generated by combining modeled air pollution predictions from the U.S. Environmental Protection Agency's Community Multi-Scale Air Quality model with air monitor data from the Environmental Protection Agency's Air Quality System. Maternal residence was geocoded and assigned pollutant concentrations averaged over weeks 3 to 8 of gestation. Binomial regression was performed and adjusted for potential confounders. RESULTS No association was observed between either PM2.5 or O3 concentrations and most birth defects. Positive effect estimates were observed between air pollution and microtia/anotia and lower limb deficiency defects, but the 95% confidence intervals were wide and included the null. CONCLUSION Overall, this study suggested a possible relationship between air pollution concentration during early pregnancy and certain birth defects (e.g., microtia/anotia, lower limb deficiency defects), although this study did not have the power to detect such an association. The risk for most birth defects does not appear to be affected by ambient air pollution. Birth Defects Research (Part A) 97:696–701, 2013. © 2013 Wiley Periodicals, Inc.

BACKGROUND: Congenital hydrocephalus is a condition characterized by accumulation of cerebrospinal fluid in the ventricles of the brain. Prenatal infections are risk factors for some birth defects. This pilot study investigated whether residual dried blood spots (DBS) could be used to assess infections as risk factors for birth defects by examining the associations between prenatal infection with Toxoplasma gondii (T. gondii) or cytomegalovirus (CMV) with congenital hydrocephalus. METHODS: Case-infants with hydrocephalus (N 5410) were identified among live-born infants using birth defects surveillance systems in California, North Carolina, and Texas. Control-infants without birth defects were randomly selected from the same geographic areas and time periods as case-infants (N 5448). We tested residual DBS from case- and control-infants for T. gondii immunoglobulin M and CMV DNA. When possible, we calculated crude odds ratios (cORs) and confidence intervals (CIs). RESULTS: Evidence for prenatal T. gondii infection was more common among case-infants (1.2%) than control-infants (0%; p 50.11), and evidence for prenatal CMV infection was higher among case-infants (1.5%) than control-infants (0.7%; cOR: 2.3; 95% CI: 0.48, 13.99). CONCLUSIONS: Prenatal infections with T. gondii and CMV occurred more often among infants with congenital hydrocephalus than control-infants, although differences were not statistically significant. This pilot study highlighted some challenges in using DBS to examine associations between certain infections and birth defects, particularly related to reduced sensitivity and specimen storage conditions. Further study with increased numbers of specimens and higher quality specimens should be considered to understand better the contribution of these infections to the occurrence of congenital hydrocephalus. Birth Defects Research (Part A) 97:431–436, 2013. V C 2013 Wiley Periodicals, Inc.

BACKGROUND: The 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. METHODS: Population-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. RESULTS: National 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. CONCLUSION: Accurate 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. Birth Defects Research (Part A) 88:1008–1016, 2010. 2010 Wiley-Liss, Inc.

Background Although clubfoot is a common birth defect, with a prevalence of approximately 1 per 1000 livebirths, the etiology of clubfoot remains largely unknown. Studies of the prevalence and risk factors for clubfoot in the United States have previously been limited to specific states. The purpose of this study was to pool data from several birth defects surveillance programs to better estimate the prevalence of clubfoot and investigate its risk factors. Methods The 10 population-based birth defects surveillance programs that participated in this study ascertained 6139 cases of clubfoot from 2001 through 2005. A random sample of 10 controls per case, matched on year and state of birth, was selected from birth certificates. Data on infant and maternal risk factors were collected from birth certificates. Prevalence was calculated by pooling the state-specific data. Conditional logistic regression was used to investigate the association between risk factors and clubfoot. Results The overall prevalence of clubfoot was 1.29 per 1000 livebirths; 1.38 among non-Hispanic whites, 1.30 among Hispanics, and 1.14 among non-Hispanic blacks or African Americans. Maternal age, parity, education, and marital status were significantly associated with clubfoot. Maternal smoking and diabetes also showed significant associations. Several of these observed associations were consistent between surveillance programs. Conclusions We estimated the prevalence of clubfoot using data from several birth defects programs, representing one-quarter of all births in the United States. Our findings underline the importance of birth defects surveillance programs and their utility in monitoring population-based prevalence and investigating risk factors.

BACKGROUND: Clubfoot is one of the most common major birth defects, with a prevalence of approximately 1 per 1,000 live births. The etiology of clubfoot is complex and not well understood, and yet, few epidemiologic studies of risk factors have been conducted. Maternal smoking has been suggested as a possible risk factor. The purpose of this population-based, case-control study was to examine the association between maternal smoking and clubfoot. METHODS: Data from the North Carolina Birth Defects Monitoring Program matched to North Carolina birth certificates and health services data were used in the analysis of 443 cases of clubfoot and 4,492 randomly sampled controls for the years 1999–2003. Smoking data were ascertained from the birth certificates, and the reliability of the data was assessed by comparing them with reported smoking from the North Carolina Pregnancy Risk Assessment Monitoring System. Multiple logistic regression was used to calculate crude and adjusted ORs and 95% CIs for smoking and clubfoot. RESULTS: The crude OR for maternal smoking during pregnancy and clubfoot was 1.49 (95% CI: 1.15, 1.92). Controlling for maternal age, race/ethnicity, infant's sex, and timing of prenatal care initiation did not appreciably change the results (adjusted OR 1.40; 95% CI: 1.07, 1.83). CONCLUSIONS: This study is consistent with the hypothesis that smoking during pregnancy is associated with a slightly increased risk of an infant being born with clubfoot. Further research is needed to confirm this association, and to identify potential genetic factors that may modify the magnitude of the risk. Birth Defects Research (Part A) 2008. © 2007 Wiley-Liss, Inc.

BACKGROUND Although many birth defect surveillance systems were developed for the primary purpose of monitoring trends and conducting epidemiologic studies, a number of programs have recognized the potential of birth defects monitoring systems for identifying and referring children who may be eligible for services. Because almost all surveillance programs maintain a registry of all children who have been diagnosed with birth defects in a particular state or other defined geographic region, registries can play an important role in identifying eligible children and providing timely referral to specialized services. METHODS We sent electronically an 18-question survey to the Centers for Disease Control and Prevention's list of State Birth Defects Surveillance Contacts in all 50 states, the District of Columbia, and Puerto Rico. The survey queried states as to whether they had or were developing a birth defect surveillance program, the extent to which they were currently using or were considering using their program as a means of identifying and referring children for services, and if so, the manner in which referrals were made. RESULTS We received completed surveys from all 50 states, Washington, DC, and Puerto Rico. Thirty-two of the fifty-two respondents stated that their state or entity has an operational birth defect surveillance program. Of these, 13 have implemented an identification and referral system within the surveillance program. All 16 states that were planning a surveillance program are also are planning or beginning to implement a program that would include an identification and referral system. Respondents cited lack of resources and confidentiality concerns as being the major barriers to implementing a referral system for their registry. CONCLUSIONS For many registries, using their surveillance data for program development purposes represents a new undertaking. This trend reflects increasing recognition of the role that state-based birth defect surveillance systems can play in supporting child-find efforts for children with special needs. In the long run, this expanded focus may further enhance the public health usefulness of birth defect surveillance programs. Birth Defects Research (Part A) 67:647–650, 2003. Published 2003 Wiley-Liss, Inc.