Leveraging automated approaches to categorize birth defects from abstracted birth hospitalization data

BACKGROUND

The Surveillance for Emerging Threats to Pregnant People and Infants Network (SET-NET) collects data abstracted from medical records and birth defects registries on pregnant people and their infants to understand outcomes associated with prenatal exposures. We developed an automated process to categorize possible birth defects for prenatal COVID-19, hepatitis C, and syphilis surveillance. By employing keyword searches, fuzzy matching, natural language processing (NLP), and machine learning (ML), we aimed to decrease the number of cases needing manual clinician review.

METHODS

SET-NET captures International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) codes and free text describing birth defects. For unstructured data, we used keyword searches, and then conducted fuzzy matching with a cut-off match score of ≥90%. Finally, we employed NLP and ML by testing three predictive models to categorize birth defect data.

RESULTS

As of June 2023, 8326 observations containing data on possible birth defects were submitted to SET-NET. The majority (n = 6758 [81%]) were matched to an ICD-10-CM code and 1568 (19%) were unable to be matched. Through keyword searches and fuzzy matching, we categorized 1387/1568 possible birth defects. Of the remaining 181 unmatched observations, we correctly categorized 144 (80%) using a predictive model.

CONCLUSIONS

Using automated approaches allowed for categorization of 99.6% of reported possible birth defects, which helps detect possible patterns requiring further investigation. Without employing these analytic approaches, manual review would have been needed for 1568 observations. These methods can be employed to quickly and accurately sift through data to inform public health responses.

Narrowing the Survival Gap: Trends in Survival of Individuals with Down Syndrome with and without Congenital Heart Defects Born 1979 to 2018

OBJECTIVE

To evaluate the hypothesis that childhood survival for individuals with Down syndrome (DS) and congenital heart defects (CHDs) has improved in recent years, approaching the survival of those with DS without CHDs.

STUDY DESIGN

Individuals with DS born from 1979 to 2018 were identified through the Metropolitan Atlanta Congenital Defects Program, a population-based birth defects surveillance system administered by the Centers for Disease Control and Prevention. Survival analysis was performed to evaluate predictors of mortality for those with DS.

RESULTS

The cohort included 1671 individuals with DS; 764 had associated CHDs. The 5-year survival in those with DS with CHD improved steadily among individuals born in the 1980s through the 2010s (from 85% to 93%; P = .01), but remained stable (96% to 95%; P = .97) in those with DS without CHDs. The presence of a CHD was not associated with mortality through 5 years of age for those born 2010 or later (hazard ratio, 2.63; 95% CI, 0.95-8.37). In multivariable analyses, atrioventricular septal defects were associated with early (<1 year) and late (>5 year) mortality, whereas ventricular septal defects were associated with intermediate (1-5 years) mortality and atrial septal defects with late mortality, when adjusting for other risk factors.

CONCLUSIONS

The gap in 5-year survival between children with DS with and without CHDs has improved over the last 4 decades. Survival after 5 years remains lower for those with CHDs, although longer follow-up is needed to determine if this difference lessens for those born in the more recent years.

Inpatient Hospitalization Costs Associated with Birth Defects Among Persons Aged <65 Years - United States, 2019

Changing treatments and medical costs necessitate updates to hospitalization cost estimates for birth defects. The 2019 National Inpatient Sample was used to estimate the service delivery costs of hospitalizations among patients aged <65 years for whom one or more birth defects were documented as discharge diagnoses. In 2019, the estimated cost of these birth defect-associated hospitalizations in the United States was $22.2 billion. Birth defect-associated hospitalizations bore disproportionately high costs, constituting 4.1% of all hospitalizations among persons aged <65 years and 7.7% of related inpatient medical costs. Updating estimates of hospitalization costs provides information about health care resource use associated with birth defects and the financial impact of birth defects across the life span and illustrates the need to determine the continued health care needs of persons born with birth defects to ensure optimal health for all.

Prevalence and descriptive epidemiology of Turner syndrome in the United States, 2000-2017: A report from the National Birth Defects Prevention Network

The lack of United States population-based data on Turner syndrome limits assessments of prevalence and associated characteristics for this sex chromosome abnormality. Therefore, we collated 2000-2017 data from seven birth defects surveillance programs within the National Birth Defects Prevention Network. We estimated the prevalence of karyotype-confirmed Turner syndrome diagnosed within the first year of life. We also calculated the proportion of cases with commonly ascertained birth defects, assessed associations with maternal and infant characteristics using prevalence ratios (PR) with 95% confidence intervals (CI), and estimated survival probability. The prevalence of Turner syndrome of any pregnancy outcome was 3.2 per 10,000 female live births (95% CI = 3.0-3.3, program range: 1.0-10.4), and 1.9 for live birth and stillbirth (≥20 weeks gestation) cases (95% CI = 1.8-2.1, program range: 0.2-3.9). Prevalence was lowest among cases born to non-Hispanic Black women compared to non-Hispanic White women (PR = 0.5, 95% CI = 0.4-0.6). Coarctation of the aorta was the most common defect (11.6% of cases), and across the cohort, individuals without hypoplastic left heart had a five-year survival probability of 94.6%. The findings from this population-based study may inform surveillance practices, prenatal counseling, and diagnosis. We also identified racial and ethnic disparities in prevalence, an observation that warrants further investigation.

Influenza vaccination during pregnancy and risk of selected major structural congenital heart defects, National Birth Defects Prevention Study 2006-2011

BACKGROUND

Although results from studies of first-trimester influenza vaccination and congenital heart defects (CHDs) have been reassuring, data are limited for specific CHDs.

METHODS

We assessed associations between reported maternal influenza vaccination, 1 month before pregnancy (B1) through end of third pregnancy month (P3), and specific CHDs using data from a multisite, population-based case-control study. Analysis included 2,982 case children diagnosed with a simple CHD (no other cardiac involvement with or without extracardiac defects) and 4,937 control children without a birth defect with estimated delivery dates during 2006-2011. For defects with ≥5 exposed case children, we used logistic regression to estimate propensity score-adjusted odds ratios (aORs) and 95% confidence intervals (CIs), adjusting for estimated delivery year and season; plurality; and maternal age at delivery, race/ethnicity, low folate intake, and smoking and alcohol use during B1P3.

RESULTS

Overall, 124 (4.2%) simple CHD case mothers and 197 (4.0%) control mothers reported influenza vaccination from 1 month before through the third pregnancy month. The aOR for any simple CHD was 0.97 (95% CI: 0.76-1.23). Adjusted ORs for specific simple CHDs ranged from 0.62 for hypoplastic left heart syndrome to 2.34 for total anomalous pulmonary venous return (TAPVR). All adjusted CIs included the null except for TAPVR.

CONCLUSIONS

Although we cannot fully exclude that exposure misclassification may have masked risks for some CHDs, findings add to existing evidence supporting the safety of inactivated influenza vaccination during pregnancy. The TAPVR result may be due to chance, but it may help inform future studies.

Influenza vaccination during pregnancy and risk of selected major structural noncardiac birth defects, National Birth Defects Prevention Study 2006-2011

PURPOSE

To assess associations between influenza vaccination during etiologically-relevant windows and selected major structural non-cardiac birth defects.

STUDY DESIGN

We analyzed data from the National Birth Defects Prevention Study, a multisite, population-based case-control study, for 8233 case children diagnosed with a birth defect and 4937 control children without a birth defect with delivery dates during 2006-2011. For all analyses except for neural tube defects (NTDs), we classified mothers who reported influenza vaccination 1 month before through the third pregnancy month as exposed; the exposure window for NTDs was 1 month before through the first pregnancy month. For defects with five or more exposed case children, we used logistic regression to estimate propensity score-adjusted odds ratios (aORs) and 95% confidence intervals (CIs), adjusting for estimated delivery year and season; plurality; maternal age, race/ethnicity, smoking and alcohol use, low folate intake; and, for NTDs, folate antagonist medications.

RESULTS

There were 334 (4.1%) case and 197 (4.0%) control mothers who reported influenza vaccination from 1 month before through the third pregnancy month. Adjusted ORs ranged from 0.53 for omphalocele to 1.74 for duodenal atresia/stenosis. Most aORs (11 of 19) were ≤1 and all adjusted CIs included the null. The unadjusted CIs for two defects, hypospadias and craniosynostosis, excluded the null. These estimates were attenuated upon covariate adjustment (hypospadias aOR: 1.25 (95% CI 0.89, 1.76); craniosynostosis aOR: 1.23 (95% CI: 0.88, 1.74)).

CONCLUSIONS

Results for several non-cardiac major birth defects add to the existing evidence supporting the safety of inactivated influenza vaccination during pregnancy. Under-reporting of vaccination may have biased estimates downward.

Prevalence of individual brain and eye defects potentially related to Zika virus in pregnancy in 22 U.S. states and territories, January 2016 to June 2017

During the Centers for Disease Control and Prevention's Zika Virus Response, birth defects surveillance programs adapted to monitor birth defects potentially related to Zika virus (ZIKV) infection during pregnancy. Pregnancy outcomes occurring during January 2016 to June 2017 in 22 U.S. states and territories were used to estimate the prevalence of those brain and eye defects potentially related to ZIKV. Jurisdictions were divided into three groups: areas with widespread ZIKV transmission, areas with limited local ZIKV transmission, and areas without local ZIKV transmission. Prevalence estimates for selected brain and eye defects and microcephaly per 10,000 live births were estimated. Prevalence ratios (PRs) and 95% confidence intervals (CIs) were estimated using Poisson regression for areas with widespread and limited ZIKV transmission compared with areas without local ZIKV transmission. Defects with significantly higher prevalence in areas of widespread transmission were pooled, and PRs were calculated by quarter, comparing subsequent quarters to the first quarter (January-March 2016). Nine defects had significantly higher prevalence in areas of widespread transmission. The highest PRs were seen in intracranial calcifications (PR = 12.6, 95% CI [7.4, 21.3]), chorioretinal abnormalities (12.5 [7.1, 22.3]), brainstem abnormalities (9.3 [4.7, 18.4]), and cerebral/cortical atrophy (6.7 [4.2, 10.8]). The PR of the nine pooled defects was significantly higher in three quarters in areas with widespread transmission. The largest difference in prevalence was observed for defects consistently reported in infants with congenital ZIKV infection. Birth defects surveillance programs could consider monitoring a subset of birth defects potentially related to ZIKV in pregnancy.

Identifying possible inaccuracy in reported birth head circumference measurements among infants in the US Zika Pregnancy and Infant Registry

BACKGROUND

The US Zika Pregnancy and Infant Registry (USZPIR) monitors infants born to mothers with confirmed or possible Zika virus infection during pregnancy. The surveillance case definition for Zika-associated birth defects includes microcephaly based on head circumference (HC).

METHODS

We assessed birth and follow-up data from infants with birth HC measurements <3rd percentile and birthweight ≥10th percentile to determine possible misclassification of microcephaly. We developed a schema informed by literature review and expert opinion to identify possible HC measurement inaccuracy using HC growth velocity and longitudinal HC measurements between 2 and 12 months of age. Two or more HC measurements were required for assessment. Inaccuracy in birth HC measurement was suspected if growth velocity was >3 cm/month in the first 3 months or HC was consistently >25th percentile during follow-up.

RESULTS

Of 6,799 liveborn infants in USZPIR, 351 (5.2%) had Zika-associated birth defects, of which 111 had birth HC measurements <3rd percentile and birthweight ≥10th percentile. Of 84/111 infants with sufficient follow-up, 38/84 (45%) were classified as having possible inaccuracy of birth HC measurement, 19/84 (23%) had HC ≥3rd percentile on follow-up without meeting criteria for possible inaccuracy, and 27/84 (32%) had continued HC <3rd percentile. After excluding possible inaccuracies, the proportion of infants with Zika-associated birth defects including microcephaly decreased from 5.2% to 4.6%.

CONCLUSIONS

About one-third of infants in USZPIR with Zika-associated birth defects had only microcephaly, but indications of possible measurement inaccuracy were common. Implementation of this schema in longitudinal studies can reduce misclassification of microcephaly.

Prevalence and mortality in children with congenital diaphragmatic hernia: a multicountry study

PURPOSE

This study determined the prevalence, mortality, and time trends of children with congenital diaphragmatic hernia (CDH).

METHODS

Twenty-five hospital- and population-based surveillance programs in 19 International Clearinghouse for Birth Defects Surveillance and Research member countries provided birth defects mortality data between 1974 and 2015. CDH cases included live births, stillbirths, or elective termination of pregnancy for fetal anomalies. Prevalence, cumulative mortality rates, and 95% confidence intervals (CIs) were calculated using Poisson regression and a Kaplan-Meier product-limit method. Joinpoint regression analyses were conducted to assess time trends.

RESULTS

The prevalence of CDH was 2.6 per 10,000 total births (95% CI: 2.5-2.7), slightly increasing between 2001 and 2012 (average annual percent change = 0.5%; 95% CI:-0.6 to 1.6). The total percent mortality of CDH was 37.7%, with hospital-based registries having more deaths among live births than population-based registries (45.1% vs. 33.8%). Mortality rates decreased over time (average annual percent change = -2.4%; 95% CI: -3.8 to 1.1). Most deaths due to CDH occurred among 2- to 6-day-old infants for both registry types (36.3%, hospital-based; 12.1%, population-based).

CONCLUSIONS

The mortality of CDH has decreased over time. Mortality remains high during the first week and varied by registry type.

A multi-country study of prevalence and early childhood mortality among children with omphalocele

BACKGROUND

Omphalocele is the second most common abdominal birth defect and often occurs with other structural and genetic defects. The objective of this study was to determine omphalocele prevalence, time trends, and mortality during early childhood, by geographical region, and the presence of associated anomalies.

METHODS

We conducted a retrospective study with 23 birth defect surveillance systems in 18 countries who are members of the International Clearinghouse for Birth Defects Surveillance and Research that submitted data on cases ascertained from 2000 through 2012, approximately 16 million pregnancies were surveyed that resulted in live births, stillbirths, or elective terminations of pregnancy for fetal anomalies (ETOPFA) and cases with omphalocele were included. Overall prevalence and mortality rates for specific ages were calculated (day of birth, neonatal, infant, and early childhood). We used Kaplan-Meier estimates with 95% confidence intervals (CI) to calculate cumulative mortality and joinpoint regression for time trend analyses.

RESULTS

The prevalence of omphalocele was 2.6 per 10,000 births (95% CI: 2.5, 2.7) and showed no temporal change from 2000-2012 (average annual percent change = -0.19%, p = .52). The overall mortality rate was 32.1% (95% CI: 30.2, 34.0). Most deaths occurred during the neonatal period and among children with multiple anomalies or syndromic omphalocele. Prevalence and mortality varied by registry type (e.g., hospital- vs. population-based) and inclusion or exclusion of ETOPFA.

CONCLUSIONS

The prevalence of omphalocele showed no temporal change from 2000-2012. Approximately one-third of children with omphalocele did not survive early childhood with most deaths occurring in the neonatal period.

Association between maternal occupational exposure to polycyclic aromatic hydrocarbons and rare birth defects of the face and central nervous system

BACKGROUND

Previous studies suggested associations between maternal smoking, a source of exposure to polycyclic aromatic hydrocarbons (PAHs) and other chemicals, and central nervous system and face birth defects; however, no previous studies have evaluated maternal occupational PAH exposure itself.

METHODS

Jobs held in the periconceptional period were retrospectively assigned for occupational PAH exposures. Associations between maternal occupational PAH exposure and selected rare defects of the face (cataracts, microphthalmia, glaucoma, microtia, and choanal atresia) and central nervous system (holoprosencephaly, hydrocephaly, cerebellar hypoplasia, and Dandy-Walker malformation) were evaluated using data from the National Birth Defects Prevention Study, a population-based case-control study in the United States. Crude and adjusted odds ratios (ORs) with 95% confidence intervals were calculated to estimate associations between each evaluated defect and PAH exposure using multivariable logistic regression.

RESULTS

Food and beverage serving, as well as cooks and food preparation occupations, were among the most frequent jobs held by exposed mothers. Cataracts, microtia, microphthalmia, and holoprosencephaly were significantly associated with PAH exposure with evidence of dose-response (P-values for trend ≤.05). Hydrocephaly was associated with any PAH exposure, but not significant for trend. Sensitivity analyses that reduced possible sources of exposure misclassification tended to strengthen associations.

CONCLUSIONS

This is the first population-based case-control study to evaluate associations between maternal occupational PAH exposures and these rare birth defects of the central nervous system and face.

Analysis of Mortality among Neonates and Children with Spina Bifida: An International Registry-Based Study, 2001-2012

BACKGROUND

Medical advancements have resulted in better survival and life expectancy among those with spina bifida, but a significantly increased risk of perinatal and postnatal mortality for individuals with spina bifida remains.

OBJECTIVES

To examine stillbirth and infant and child mortality among those affected by spina bifida using data from multiple countries.

METHODS

We conducted an observational study, using data from 24 population- and hospital-based surveillance registries in 18 countries contributing as members of the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR). Cases of spina bifida that resulted in livebirths or stillbirths from 20 weeks' gestation or elective termination of pregnancy for fetal anomaly (ETOPFA) were included. Among liveborn spina bifida cases, we calculated mortality at different ages as number of deaths among liveborn cases divided by total number of liveborn cases with spina bifida. As a secondary outcome measure, we estimated the prevalence of spina bifida per 10 000 total births. The 95% confidence interval for the prevalence estimate was estimated using the Poisson approximation of binomial distribution.

RESULTS

Between years 2001 and 2012, the overall first-week mortality proportion was 6.9% (95% CI 6.3, 7.7) and was lower in programmes operating in countries with policies that allowed ETOPFA compared with their counterparts (5.9% vs. 8.4%). The majority of first-week mortality occurred on the first day of life. In programmes where information on long-term mortality was available through linkage to administrative databases, survival at 5 years of age was 90%-96% in Europe, and 86%-96% in North America.

CONCLUSIONS

Our multi-country study showed a high proportion of stillbirth and infant and child deaths among those with spina bifida. Effective folic acid interventions could prevent many cases of spina bifida, thereby preventing associated childhood morbidity and mortality.

The impact of the ICD-9-CM to ICD-10-CM transition on the prevalence of birth defects among infant hospitalizations in the United States

BACKGROUND

Many public health surveillance programs utilize hospital discharge data in their estimation of disease prevalence. These databases commonly use the International Classification of Diseases (ICD) coding scheme, which transitioned from the ICD-9 clinical modification (ICD-9-CM) to ICD-10-CM on October 1, 2015. This study examined this transition's impact on the prevalence of major birth defects among infant hospitalizations.

METHODS

Using data from the Agency for Health Care Research and Quality-sponsored National Inpatient Sample, hospitalizations during the first year of life with a discharge date between January 1, 2012 and December 31, 2016 were used to estimate the monthly national hospital prevalence of 46 birth defects for the ICD-9-CM and ICD-10-CM timeframes separately. Survey-weighted Poisson regression was used to estimate 95% confidence intervals for each hospital prevalence. Interrupted time series framework and corresponding segmented regression was used to estimate the immediate change in monthly hospital prevalence following the ICD-9-CM to ICD-10-CM transition.

RESULTS

Between 2012 and 2016, over 21 million inpatient hospitalizations occurred during the first year of life. Among the 46 defects studied, statistically significant decreases in the immediate hospital prevalence of five defects and significant increases in the immediate hospital prevalence of eight defects were observed after the ICD-10-CM transition.

CONCLUSIONS

Changes in prevalence were expected based on changes to ICD-10-CM. Observed changes for some conditions may result from variation in monthly hospital prevalence or initial unfamiliarity of coders with ICD-10-CM. These findings may help birth defects surveillance programs evaluate and interpret changes in their data related to the ICD-10-CM transition.

Factors associated with recruitment, surveillance participation, and retention in an observational study of pregnant women and influenza

Background

This report describes the results of recruitment efforts and the subsequent participation of pregnant women in study activities in a 2010–2012 observational study focused on influenza illness and vaccination in California and Oregon, USA.

Methods

Socio-demographic and health characteristics extracted from electronic medical records were compared among pregnant women who enrolled in the study, refused to participate, or were never reached for study invitation. These characteristics plus additional self-reported information were compared between women who enrolled in two study tracks: a prospective cohort vs. women enrolled following an acute respiratory illness (ARI) medical encounter. The characteristics of women who participated in weekly ARI surveillance (cohort enrollees, year one) and a 6-month follow-up interview (all enrollees) were also examined.

Results

In year one, we reached 51% (6938/13,655) of the potential participants we tried to contact by telephone, and 20% (1374/6938) of the women we invited agreed to join the prospective cohort. Women with chronic medical conditions, pregnancy complications, and medical encounters for ARI (prior to pregnancy or during the study period) were more likely to be reached for recruitment and more likely to enroll in the cohort. Twenty percent of cohort enrollees never started weekly surveillance reports; among those who did, reports were completed for 55% of the surveillance weeks. Receipt of the influenza vaccine was higher among women who joined the cohort (76%) than those who refused (56%) or were never reached (54%). In contrast, vaccine uptake among medical enrollees in year one (54%; 53/98) and two (52%; 79/151) was similar to other pregnant women in those years. Study site, white race, non-Hispanic ethnicity, and not having a child aged < 13 years at home were most consistently associated with joining as a cohort or medical enrollee and completing study activities after joining.

Conclusions

We observed systematic differences in socio-demographic and health characteristics across different levels of participant engagement and between cohort and medical enrollees. More methodological research and innovation in conducting prospective observational studies in this population are needed, especially when extended participant engagement and ongoing surveillance are required.

Electronic supplementary material

The online version of this article (10.1186/s12884-019-2280-0) contains supplementary material, which is available to authorized users.

Population-based pregnancy and birth defects surveillance in the era of Zika virus

BACKGROUND

Zika virus is a newly recognized human teratogen; monitoring its impact on the birth prevalence of microcephaly and other adverse pregnancy outcomes will continue to be an urgent need in the United States and worldwide.

METHODS

When the Centers for Disease Control and Prevention (CDC) activated the Emergency Operations Center for the Zika virus outbreak response in January of 2016, public health leadership recognized that a joint, coordinated effort was required between activities focused on the effects of the infection among pregnant women and those focused on birth defects in fetuses and infants. Before the introduction of Zika virus in the Americas, population-based birth defects surveillance occurred independently of pregnancy surveillance activities.

RESULTS

The coordination of pregnancy surveillance and birth defects surveillance implemented through the CDC Zika virus response represents a paradigm shift.

CONCLUSION

Coordination of these surveillance systems provides an opportunity to capture information from both a prospective and retrospective approach. This relatively modest investment in the public health infrastructure can continue to protect pregnant women and their infants during the ongoing response to Zika virus and in the next emergent threat to maternal and child health. Birth Defects Research 109:372-378, 2017. © 2017 Wiley Periodicals, Inc.

Population-based microcephaly surveillance in the United States, 2009 to 2013: An analysis of potential sources of variation

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 <20 years (11.5) and ≥40 years (13.2). For gestational age and birth weight, the highest prevalence was among infants <32 weeks gestation and infants <1500 gm. Case definitions varied; 41.8% of cases had an HC ≥ the 10^th percentile for sex and gestational age.

CONCLUSION

Differences in methods, population distribution of maternal/infant characteristics, and case definitions for microcephaly can contribute to the wide range of observed prevalence estimates across individual birth defects surveillance programs. Addressing these factors in the setting of Zika virus infection can improve the quality of prevalence estimates. Birth Defects Research (Part A) 106:972-982, 2016. © 2016 Wiley Periodicals, Inc.

Baseline Prevalence of Birth Defects Associated with Congenital Zika Virus Infection - Massachusetts, North Carolina, and Atlanta, Georgia, 2013-2014

Zika virus infection during pregnancy can cause serious brain abnormalities, but the full range of adverse outcomes is unknown (1). To better understand the impact of birth defects resulting from Zika virus infection, the CDC surveillance case definition established in 2016 for birth defects potentially related to Zika virus infection* (2) was retrospectively applied to population-based birth defects surveillance data collected during 2013-2014 in three areas before the introduction of Zika virus (the pre-Zika years) into the World Health Organization's Region of the Americas (Americas) (3). These data, from Massachusetts (2013), North Carolina (2013), and Atlanta, Georgia (2013-2014), included 747 infants and fetuses with one or more of the birth defects meeting the case definition (pre-Zika prevalence = 2.86 per 1,000 live births). Brain abnormalities or microcephaly were the most frequently recorded (1.50 per 1,000), followed by neural tube defects and other early brain malformations^† (0.88), eye abnormalities without mention of a brain abnormality (0.31), and other consequences of central nervous system (CNS) dysfunction without mention of brain or eye abnormalities (0.17). During January 15-September 22, 2016, the U.S. Zika Pregnancy Registry (USZPR) reported 26 infants and fetuses with these same defects among 442 completed pregnancies (58.8 per 1,000) born to mothers with laboratory evidence of possible Zika virus infection during pregnancy (2). Although the ascertainment methods differed, this finding was approximately 20 times higher than the proportion of one or more of the same birth defects among pregnancies during the pre-Zika years. These data demonstrate the importance of population-based surveillance for interpreting data about birth defects potentially related to Zika virus infection.

Inpatient Hospitalization Costs Associated with Birth Defects Among Persons of All Ages - United States, 2013

In the United States, major structural or genetic birth defects affect approximately 3% of live births (1) and are responsible for 20% of infant deaths (2). Birth defects can affect persons across their lifespan and are the cause of significant lifelong disabilities. CDC used the Healthcare Cost and Utilization Project (HCUP) 2013 National Inpatient Sample (NIS), a 20% stratified sample of discharges from nonfederal community hospitals, to estimate the annual cost of birth defect-associated hospitalizations in the United States, both for persons of all ages and by age group. Birth defect-associated hospitalizations had disproportionately high costs, accounting for 3.0% of all hospitalizations and 5.2% of total hospital costs. The estimated annual cost of birth defect-associated hospitalizations in the United States in 2013 was $22.9 billion. Estimates of the cost of birth defect-associated hospitalizations offer important information about the impact of birth defects among persons of all ages on the overall health care system and can be used to prioritize prevention, early detection, and care.

Clinician's Primer to ICD-10-CM Coding for Cleft Lip/Palate Care

On October 1,2015, the United States required use of the Clinical Modification of the International Classification of Diseases, 10th Revision (ICD-10-CM) for diagnostic coding. This primer was written to assist the cleft care community with understanding and use of ICD-10-CM for diagnostic coding related to cleft lip and/or palate (CL/P).

Interim Guidelines for the Evaluation and Testing of Infants with Possible Congenital Zika Virus Infection - United States, 2016

CDC has developed interim guidelines for health care providers in the United States who are caring for infants born to mothers who traveled to or resided in an area with Zika virus transmission during pregnancy. These guidelines include recommendations for the testing and management of these infants. Guidance is subject to change as more information becomes available; the latest information, including answers to commonly asked questions, can be found online (http://www.cdc.gov/zika). Pediatric health care providers should work closely with obstetric providers to identify infants whose mothers were potentially infected with Zika virus during pregnancy (based on travel to or residence in an area with Zika virus transmission [http://wwwnc.cdc.gov/travel/notices]), and review fetal ultrasounds and maternal testing for Zika virus infection (see Interim Guidelines for Pregnant Women During a Zika Virus Outbreak*) (1). Zika virus testing is recommended for 1) infants with microcephaly or intracranial calcifications born to women who traveled to or resided in an area with Zika virus transmission while pregnant; or 2) infants born to mothers with positive or inconclusive test results for Zika virus infection. For infants with laboratory evidence of a possible congenital Zika virus infection, additional clinical evaluation and follow-up is recommended. Health care providers should contact their state or territorial health department to facilitate testing. As an arboviral disease, Zika virus disease is a nationally notifiable condition.

A population-based study of the association of prenatal diagnosis with survival rate for infants with congenital heart defects

Prenatal diagnosis has been shown to improve preoperative morbidity in newborns with congenital heart defects (CHDs), but there are conflicting data as to the association with mortality. We performed a population-based, retrospective, cohort study of infants with prenatally versus postnatally diagnosed CHDs from 1994 to 2005 as ascertained by the Metropolitan Atlanta Congenital Defects Program. Among infants with isolated CHDs, we estimated 1-year Kaplan-Meier survival probabilities for prenatal versus postnatal diagnosis and estimated Cox proportional hazard ratios adjusted for critical CHD status, gestational age, and maternal race/ethnicity. Of 539,519 live births, 4,348 infants had CHDs (411 prenatally diagnosed). Compared with those with noncritical defects, those with critical defects were more likely to be prenatally diagnosed (58% vs 20%, respectively, p <0.001). Of the 3,146 infants with isolated CHDs, 1-year survival rate was 77% for those prenatally diagnosed (n = 207) versus 96% for those postnatally diagnosed (n = 2,939, p <0.001). Comparing 1-year survival rate among those with noncritical CHDs alone (n = 2,455) showed no difference between prenatal and postnatal diagnoses (96% vs 98%, respectively, p = 0.26), whereas among those with critical CHDs (n = 691), prenatally diagnosed infants had significantly lower survival rate (71% vs 86%, respectively, p <0.001). Among infants with critical CHDs, the adjusted hazard ratio for 1-year mortality rate for those prenatally versus postnatally (reference) diagnosed was 2.51 (95% confidence interval 1.72 to 3.66). In conclusion, prenatal diagnosis is associated with lower 1-year survival rate for infants with isolated critical CHDs but shows no change for those with isolated noncritical CHDs. More severe disease among the critical CHD subtypes diagnosed prenatally might explain these findings.

Frequency of prenatal cytogenetic diagnosis and pregnancy outcomes by maternal race-ethnicity, and the effect on the prevalence of trisomy 21, Metropolitan Atlanta, 1996-2005

The prevalence of trisomy 21 has been reported to differ by race-ethnicity, however, the results are inconsistent and the cause of the differences is unknown. Using data from 1996 to 2005 from the Metropolitan Atlanta Congenital Defects Program (MACDP), we analyzed the use of prenatal cytogenetic testing and the subsequent use of elective termination among pregnancies affected with any MACDP-eligible birth defect and trisomy 21, by maternal race-ethnicity. We then examined whether these factors could explain the observed differences in the prevalence of trisomy 21 among race-ethnicity groups. Among all pregnancies with birth defects, prenatal cytogenetic testing as well as elective terminations after an abnormal prenatal cytogenetic test result were observed less frequently among Hispanic women than among non-Hispanic white women (odds ratio [OR] 0.66, 95% confidence interval [CI] 0.56-0.78, respectively). In pregnancies affected by trisomy 21, both the Hispanic and the non-Hispanic black populations had more live births (89.5% and 77.8%, respectively) and fewer elective terminations (5.7% and 15.2%, respectively) compared to the non-Hispanic white population (63.0% live births, 32.3% elective terminations). After adjusting for elective terminations, non-Hispanic white mothers had a higher live birth prevalence of trisomy 21 compared to non-Hispanic black (OR 0.64, 95% CI 0.54-0.76) or Hispanic mothers (OR 0.69, 95% CI 0.55-0.86). Overall, our data suggest that factors associated with decisions made about the use of prenatal testing, and about pregnancy management after testing, might play a large role in the race-ethnicity differences observed in the live birth prevalence of trisomy 21.

Medications in the first trimester of pregnancy: most common exposures and critical gaps in understanding fetal risk

PURPOSE

To determine which medications are most commonly used by women in the first trimester of pregnancy and identify the critical gaps in information about fetal risk for those medications.

METHODS

Self-reported first-trimester medication use was assessed among women delivering liveborn infants without birth defects and serving as control mothers in two large case-control studies of major birth defects. The Teratology Information System (TERIS) expert Advisory Board ratings of quality and quantity of data available to assess fetal risk were reviewed to identify information gaps.

RESULTS

Responses from 5381 mothers identified 54 different medication components used in the first trimester by at least 0.5% of pregnant women, including 31 prescription and 23 over-the-counter medications. The most commonly used prescription medication components reported were progestins from oral contraceptives, amoxicillin, progesterone, albuterol, promethazine, and estrogenic compounds. The most commonly used over-the-counter medication components reported were acetaminophen, ibuprofen, docusate, pseudoephedrine, aspirin, and naproxen. Among the 54 most commonly used medications, only two had "Good to Excellent" data available to assess teratogenic risk in humans, based on the TERIS review.

CONCLUSIONS

For most medications commonly used in pregnancy, there are insufficient data available to characterize the fetal risk fully, limiting the opportunity for informed clinical decisions about the best management of acute and chronic disorders during pregnancy. Future research efforts should be directed at these critical knowledge gaps.

Trends in cytogenetic testing and identification of chromosomal abnormalities among pregnancies and children with birth defects, metropolitan Atlanta, 1968-2005

The purpose of this study was to examine changes in the use of cytogenetic testing and identification of chromosomal abnormalities among pregnancies and children with birth defects. Utilizing data from 1968 to 2005 from the Metropolitan Atlanta Congenital Defects Program, we analyzed trends in the frequency and timing (prenatal or postnatal) of cytogenetic testing and the prevalence of recognized chromosome abnormalities among pregnancies and children with birth defects (n = 51,424). Cytogenetic testing of pregnancies and children with birth defects increased from 7.2% in 1968 to 25.0% in 2005, as did the identification of chromosomal abnormalities (2.2% in 1968 to 6.8% in 2005). The use of prenatal cytogenetic testing decreased from 1996 to 2005 among women aged ≥35 years. Identification of chromosomal abnormalities in pregnancies and children with birth defects increased from 1968 to 2005, possibly due to increased testing, improved diagnostic techniques, or increasing maternal age. The decline in prenatal cytogenetic testing observed among mothers aged ≥35 years may be related to the availability of improved prenatal screening techniques, resulting in a reduction in the utilization of invasive diagnostic tests.

The contribution of chromosomal abnormalities to congenital heart defects: a population-based study

We aimed to assess the frequency of chromosomal abnormalities among infants with congenital heart defects (CHDs) in an analysis of population-based surveillance data. We reviewed data from the Metropolitan Atlanta Congenital Defects Program, a population-based birth-defects surveillance system, to assess the frequency of chromosomal abnormalities among live-born infants and fetal deaths with CHDs delivered from January 1, 1994, to December 31, 2005. Among 4430 infants with CHDs, 547 (12.3%) had a chromosomal abnormality. CHDs most likely to be associated with a chromosomal abnormality were interrupted aortic arch (type B and not otherwise specified; 69.2%), atrioventricular septal defect (67.2%), and double-outlet right ventricle (33.3%). The most common chromosomal abnormalities observed were trisomy 21 (52.8%), trisomy 18 (12.8%), 22q11.2 deletion (12.2%), and trisomy 13 (5.7%). In conclusion, in our study, approximately 1 in 8 infants with a CHD had a chromosomal abnormality. Clinicians should have a low threshold at which to obtain testing for chromosomal abnormalities in infants with CHDs, especially those with certain types of CHDs. Use of new technologies that have become recently available (e.g., chromosomal microarray) may increase the identified contribution of chromosomal abnormalities even further.

Obstetrician-gynaecologist knowledge of and access to information about the risks of medication use during pregnancy

OBJECTIVE

To assess opinions, knowledge, and informational resources of obstetrician-gynaecologists regarding the safety of medication use during pregnancy.

METHODS

A questionnaire was mailed to 770 members of the American College of Obstetricians and Gynecologists who participate in the Collaborative Ambulatory Research Network.

RESULTS

The response rate was 58%. Of these, 305 respondents provide both routine gynecologic and obstetric care and are the focus of the study. There was wide variation in obstetrician-gynaecologists' assessments of the safety for the foetus of medications ranging from aspirin to valproic acid. The Physicians' Desk Reference was most frequently (75%) cited as a source of information about medication safety. Forty-two percent of obstetrician-gynaecologists selected lack of sufficient information on medications as the greatest barrier to counselling pregnant women about their use, while only 4% selected lack of access to information as the greatest barrier. Most (79%) obstetrician-gynaecologists indicated they would be willing to participate in pregnancy exposure registries, but far fewer (24%) reported having done so.

CONCLUSION

These results emphasise the need for safety information about the effects of medication use during pregnancy and suggest that pregnancy exposure registries are underutilised.

Management of prescription and nonprescription drug use during pregnancy

OBJECTIVE

To assess screening and treatment patterns of obstetrician-gynecologists regarding medication use during pregnancy.

METHODS

A questionnaire was mailed to 770 members of the American College of Obstetricians and Gynecologists who participate in the Collaborative Ambulatory Research Network.

RESULTS

The response rate was 58%. Most respondents reported always asking pregnant patients about use of over-the-counter (OTC) (86%) and prescription (98%) drugs; 24% reported not always asking about alternative medications. Far fewer reported always asking nonpregnant patients about use of alcohol (67%), illegal drugs (51%) and OTC medications (52%) than pregnant patients. Two-fifths (41%) reported prescribing a medication during pregnancy for which they had insufficient information about potential effects on the fetus; nearly half (47%) reported that there are medical conditions for which they would like to prescribe medications but do not due to insufficient safety information. Physician responses indicate that they are less likely to refer pregnant than nonpregnant patients to a specialist for treatment of certain conditions.

CONCLUSIONS

These results indicate that obstetrician-gynecologists sometimes prescribe medications for pregnant patients under less than optimal conditions and emphasize the importance of generating up-to-date information on effects of medications during pregnancy and having it readily available to health care providers.

Pandemic influenza and pregnant women: summary of a meeting of experts

Pandemic Influenza: Special Considerations for Pregnant Women was a meeting convened by the Centers for Disease Control and Prevention in 2008 to obtain input from experts and key partners regarding clinical management of pregnant women and related public health actions to be taken during a pandemic. Meeting goals were to discuss issues specific to pregnant women, identify gaps in knowledge, and develop a public health approach for pregnant women in the event of a pandemic. The meeting focused on 4 main topics: prophylaxis and treatment with influenza antiviral and other medications, vaccine use, nonpharmaceutical interventions and health care planning, and communications. Participants reviewed the available evidence to guide action in each of these areas and identified areas of critical needs for future research.

Including prenatal diagnoses in birth defects monitoring: Experience of the Metropolitan Atlanta Congenital Defects Program

BACKGROUND

Advances in prenatal diagnosis have led to changes in the management of pregnancies affected with birth defects. These changes pose unique challenges for birth defects monitoring programs which use hospital-based sources.

METHODS

In 1994, Metropolitan Atlanta Congenital Defects Program (MACDP) abstractors began to visit area perinatologists' offices to identify pregnancies diagnosed prenatally with fetal defects. These pregnancies were then linked with existing MACDP cases and the hospital deliveries abstracted. Those without a hospital delivery were included as having unknown outcomes. Prenatally diagnosed defects were classified as definite or possible based on the certainty of the prenatal description. For 1995-2004, we calculated minimum and maximum adjusted defect prevalences by adding definite prenatal defects, and definite plus possible prenatal defects, to the hospital-based cases.

RESULTS

We identified 1009 pregnancies with a prenatally diagnosed defect not ascertained from MACDP hospital sources. Including these increased the total defect prevalence from 28 per 1000 live births to a minimum of 29.94 (6.9% increase) and maximum of 30.14 (7.7% increase) per 1000. The minimum increase was greater than 50% for conjoined twins, triploidy, craniorachischisis, cystic hygroma, Klinefelter syndrome, anencephaly, Turner syndrome, and trisomies 13, 18 and 21 among mothers >or=35.

CONCLUSIONS

These data reflect the variety of congenital abnormalities that can be detected prenatally and the importance of including prenatal diagnoses in birth defects monitoring data. Birth defects monitoring programs should assess individually the extent to which prenatal diagnosis can affect the accuracy and completeness of their data. Birth Defects Research (Part A), 2009. Published 2008 Wiley-Liss, Inc.

FRIL: A tool for comparative record linkage

A fine-grained record integration and linkage tool (FRIL) is presented. The tool extends traditional record linkage tools with a richer set of parameters. Users may systematically and iteratively explore the optimal combination of parameter values to enhance linking performance and accuracy. Results of linking a birth defects monitoring program and birth certificate data using FRIL show 99% precision and 95% recall rates when compared to results obtained through handcrafted algorithms, and the process took significantly less time to complete. Experience and experimental result suggest that FRIL has the potential to increase the accuracy of data linkage across all studies involving record linkage. In particular, FRIL will enable researchers to assess objectively the quality of linked data.

Trisomies 13 and 18: population prevalences, characteristics, and prenatal diagnosis, metropolitan Atlanta, 1994-2003

In recent years, prenatal diagnosis and elective pregnancy termination have affected the reported birth prevalence of trisomies 13 and 18. We examined the prevalence and characteristics of these conditions using 1994-2003 data from a population-based surveillance system, the Metropolitan Atlanta Congenital Defects Program. Including fetal deaths and elective terminations increased the number of affected pregnancies by 58.7% for trisomy 13 and 72.2% for trisomy 18. Prenatal cytogenetic testing was reported in 70.8% of trisomy 13 cases and 76.1% of trisomy 18 cases. Among those with prenatal cytogenetic tests, 60.8% of trisomy 13 and 59.7% of trisomy 18 cases were electively terminated. Compared with non-Hispanic whites, non-Hispanic black race was associated with a decreased frequency of prenatal cytogenetic testing for both trisomy 13 and trisomy 18 (OR 0.24, 95% CI: 0.08-0.78 and OR 0.32, 95% CI: 0.14-0.69, respectively). The reported rates of prenatal cytogenetic testing remained stable throughout the period. As expected, maternal age > or =35 years was a risk factor for both conditions. However, while 67.1% (n = 55) of the trisomy 18 case mothers were > or =35 years, only 46.9% (n = 15) of the trisomy 13 case mothers were > or =35 years. Among live-born infants, the sex ratio among trisomy 18 infants showed an increased proportion of females: 60.4% female versus 39.6% male. However, the proportion was 48.3% female and 51.7% male among fetuses that were electively terminated in the second trimester. Inclusion of pregnancies that are prenatally diagnosed is critical for accurate surveillance and population-based analyses of these conditions.

Interpreting changes in the epidemiology of anencephaly and spina bifida following folic acid fortification of the U.S. grain supply in the setting of long-term trends, Atlanta, Georgia, 1968-2003

BACKGROUND

The prevalence of anencephaly (AN) and spina bifida (SB) was declining long before fortification of enriched grains in the U.S. with folic acid. We examined whether changes in these defects surrounding fortification could be distinguished from preexisting trends.

METHODS

We used data from the Metropolitan Atlanta Congenital Defects Program to identify three ascertainment periods: Period 1 (1968-1981), prenatal diagnoses rarely made; Period 2 (1981-1993), prenatal diagnoses made but not ascertained; Period 3 (1994-2003), prenatal diagnoses ascertained. We compared the annual percent change (APC) in AN and SB for each period using Poisson regression, then compared prevalences during each period for categories of pregnancy outcome, sex, race, gravidity, and maternal age.

RESULTS

The prevalence of AN (N = 434) and SB (N = 663) declined during 1968-2003. The APCs in Periods 1, 2, and 3, respectively, were -6.9%, -2.9%, and -6.8% for AN, and -7.1%, -7.0%, and -6.2% for SB; 95% confidence intervals around the APCs for Periods 2 and 3 overlapped for both defects. Prevalence ratios (PRs) for females relative to males decreased for AN (2.3 in Period 1; 1.2 in Period 3); PRs for whites relative to blacks or African Americans decreased for both AN (2.7 in Period 1; 1.2 in Period 3) and SB (2.5 in Period 1; 1.1 in Period 3).

CONCLUSIONS

Our analysis suggests that changes in AN and SB surrounding folic acid fortification (Period 3) could be part of preexisting trends. This must be considered when evaluating prevention efforts.

Prophylaxis and treatment of pregnant women for emerging infections and bioterrorism emergencies

Infectious disease emergency preparedness planners should consider the special medical issues of pregnant women.

Emerging infectious disease outbreaks and bioterrorism attacks warrant urgent public health and medical responses. Response plans for these events may include use of medications and vaccines for which the effects on pregnant women and fetuses are unknown. Healthcare providers must be able to discuss the benefits and risks of these interventions with their pregnant patients. Recent experiences with outbreaks of severe acute respiratory syndrome, monkeypox, and anthrax, as well as response planning for bioterrorism and pandemic influenza, illustrate the challenges of making recommendations about treatment and prophylaxis for pregnant women. Understanding the physiology of pregnancy, the factors that influence the teratogenic potential of medications and vaccines, and the infection control measures that may stop an outbreak will aid planners in making recommendations for care of pregnant women during large-scale infectious disease emergencies.

Are encephaloceles neural tube defects?

OBJECTIVE

Encephalocele is classified as a neural tube defect, but questions have been raised regarding whether its epidemiological characteristics are similar to those of other neural tube defects.

DESIGN

We compared characteristics of temporal trends in, and the impact of folic acid grain fortification on, the prevalence of encephalocele, spina bifida, and anencephaly using data from the Metropolitan Atlanta Congenital Defects Program, a population-based birth defects surveillance system. Prevalences of encephalocele, spina bifida, and anencephaly were compared by maternal age, gender, race, birth weight, ascertainment period (1968-1981, 1982-1993, or 1994-2002), and fortification period (1994-1996 [prefortification] and 1998-2002 [postfortification]) using prevalence ratios with 95% confidence intervals. Temporal trends were assessed using Poisson and negative binomial regression models.

RESULTS

Prevalence rates of encephalocele (n = 167), spina bifida (n = 650), and anencephaly (n = 431) were 1.4, 5.5, and 3.7 per 10 000 live births, respectively. Encephalocele was similar to anencephaly in showing an increased prevalence among girls and multiple gestation pregnancies and to spina bifida and anencephaly in an annual prevalence decrease between 1968 and 2002 (-1.2% for encephalocele, -4.2% for spina bifida, and -3.6% for anencephaly). With fortification, prevalence decreased for spina bifida but not significantly for encephalocele or anencephaly.

CONCLUSIONS

Encephalocele shows more similarities to spina bifida or anencephaly than it shows differences with respect to characteristics, temporal trend, and impact of fortification. Additional studies should be done to explore the etiologic heterogeneity of encephalocele using better markers of folate status and a wider range of risk factors.