An expanded public health role for birth defects surveillance

The Impact of Different Case Ascertainment Definitions on the Prevalence of Major Congenital Malformations and their Association with Asthma During Pregnancy

Objectives To compare the prevalence of major malformations using different case ascertainment definitions and to evaluate their impact on maternal asthma-major malformations association. Methods A cohort of pregnancies with and without asthma between 1990 and 2010 was formed. We used two classification methods: the Two step Congenital Malformation Classification (TCMC) and the Canadian Congenital Anomalies Surveillance System (CCASS). Within each method, three case definitions were compared: (1) ≥1 diagnosis in the hospital database; (2) ≥1 diagnosis in the hospital database or ≥2 in the medical claims; and (3) ≥1 diagnosis in the hospital database or ≥1 in the medical claims. We calculated the prevalence of major malformations and adjusted odds ratios (aORs) for maternal asthma association. Results Of 467,946 pregnancies, 12.3 % were with active asthma. The prevalence estimates were: TCMC 5.10-7.08 % and CCASS 7.03-10.57 %. Asthma-major malformations association was weaker with the CCASS (aOR 1.14-1.20) versus TCMC (aOR 1.22-1.26). Discussion The case ascertainment definitions with ≥1 hospitalization are likely to be the most reliable in similar administrative databases. The case ascertainment definition had a considerable impact on the prevalence of major malformations, but hardly influenced the aORs. Future studies should formally assess the validity of the case ascertainment definitions and allow generalizability to other maternal exposures.

Assessing the Practices of Population-Based Birth Defects Surveillance Programs Using the CDC Strategic Framework, 2012

OBJECTIVE

We assessed the practices of U.S. population-based birth defects surveillance programs in addressing current and emergent public health needs.

METHODS

Using the CDC Strategic Framework considerations for public health surveillance (i.e., lexicon and standards, legal authority, technological advances, workforce, and analytic capacity), during 2012 and 2013, we conducted a survey of all U.S. operational birth defects programs (n=43) soliciting information on legal authorities, case definition and clinical information collected, types of data sources, and workforce staffing. In addition, we conducted semi-structured interviews with nine program directors to further understand how programs are addressing current and emergent needs.

RESULTS

Three-quarters of birth defects surveillance programs used national guidelines for case definition. Most birth defects surveillance programs (86%) had a legislative mandate to conduct surveillance, and many relied on a range of prenatal, postnatal, public health, and pediatric data sources for case ascertainment. Programs reported that the transition from paper to electronic formats was altering the information collected, offering an opportunity for remote access to improve timeliness for case review and verification. Programs also reported the growth of pooled, multistate data collaborations as a positive development. Needs identified included ongoing workforce development to improve information technology and analytic skills, more emphasis on data utility and birth defects-specific standards for health information exchange, and support to develop channels for sharing ideas on data interpretation and dissemination.

CONCLUSION

The CDC Strategic Framework provided a useful tool to determine the birth defects surveillance areas with positive developments, such as multi-state collaborative epidemiologic studies, and areas for improvement, such as preparation for health information exchanges and workforce database and analytic skills. Our findings may inform strategic deliberations for enhancing the effectiveness of birth defects surveillance programs.

Newborn screening for critical congenital heart disease: essential public health roles for birth defects monitoring programs

Newborn screening for critical congenital heart defects, added in September 2011 to the Recommended Uniform Screening Panel in the United States, is a new public health priority and has particular relevance for state birth defects surveillance programs. In this commentary, we review the background to potential involvement by birth defects programs with screening, and detail key questions that these programs can evaluate: (1) health outcomes after newborn screening among affected children; (2) missed primary targets of screening (i.e., affected children who were not screened or had false-negative screens); (3) burden and screening accuracy for secondary targets; (4) the role of altitude, sociodemographic characteristics, and other special circumstances; (5) the contribution of prenatal and clinical diagnoses before newborn screening; and (6) costs and service utilization. To address these issues, monitoring programs will need to pay particular attention to: (1) data sources and quality; (2) timeliness; (3) long-term follow-up for comprehensive outcomes; (4) reporting standards; and (5) state and national program coordination. Although some aspects of involvement with these screening programs will require new partnerships and paradigm shifts in birth defects program operations, the visibility of these screening programs among stakeholders will also provide birth defects programs with new opportunities to demonstrate their usefulness.

Very rare defects: what can we learn?

The International Clearinghouse for Birth Defects Surveillance and Research conducted a study on very rare defects (VRDs) to test methodologies in their population surveillance and to increase the knowledge of their epidemiology. Eight VRDs: acardia (AC), amelia (AM), bladder exstrophy (BE), cloaca exstrophy (CE), conjoined twins (CT), cyclopia (CY), "true" phocomelia (PH), and sirenomelia (SI) were selected, all of whom showed prevalences in the order of 1/100,000 births, except for BE: 1/48,000 births. Materials in this investigation from 25 million pregnancy outcomes, were provided by 22 Clearinghouse-member programs. The study protocol provided a working definition, a summary of the phenotypic characteristic, and a list of ICD-9 and ICD-10 codes for each VRDs. Learned lessons include: (1) The suspected associations of decreasing risk with advancing maternal age in AM and SI, and increasing risk in BE, and increasing frequency of twins in SI, were confirmed. (2) Morphologically similar defects showed dissimilar epidemiological characteristics, namely, AM and PH, and BE and CE. (3) Heterogeneity in total prevalences for most VRDs among different surveillance programs were attributed to operational reasons, except for SI and CT in which Amerindian ethnicity seems to be associated with higher prevalence. (4) Verbatim description is essential and must be stored in electronic files. In addition to codes. (5) Dysmorphologists or clinical geneticists are an essential part of the coordinating team of the surveillance program. (6) ICD coding system is insufficient. (7) Surveillance programs should be a valuable source of information on exposures to risk factors during pregnancy.