The surveillance of birth defects: the usefulness of the revised US standard birth certificate

Myanmar Articulation, Resonation, Nasal Emission, and Nasal Turbulence Test: A Preliminary Study

Background  This article describes the development of the Myanmar Articulation, Resonation, Nasal Emission, and Nasal Turbulence test for children with cleft lip and palate (CLP), and evaluation of its validity and reliability. Methods  It was created by three Thai researchers and a Burmese research assistant based on Burmese phonology. The content validity was evaluated by six Burmese language experts. All test items were divided into three groups: high-pressure oral consonants, low-pressure oral consonants, and nasal consonants. Results  All items (58-word and 32-phrase/sentence) gave an excellent level of the expert agreement (item-level content validity indexes = 1.00). The target items were illustrated as color pictures. Each picture was clearly drawn and easy to identify. As a pilot study of face validity, all pictures were administered to 10 typical-developing children. The actual testing was assessed by 10 CLP children, and the developed test was analyzed through consultation of the Burmese teachers and interpreters from a speech camp. Testing scores for a total including three groups of target items were shown acceptable for internal consistency reliability (ranged from 0.4 to 0.88). Conclusion  The constructed test is valid in terms of its content.

Congenital anomalies associated with oil and gas development and resource extraction: a population-based retrospective cohort study in Texas

BACKGROUND

Oil and gas extraction-related activities produce air and water pollution that contains known and suspected teratogens. To date, health impacts of in utero exposure to these activities is largely unknown.

OBJECTIVE

We investigated associations between in utero exposure to oil and gas extraction activity in Texas, one of the highest producers of oil and gas, and congenital anomalies.

METHODS

We created a population-based birth cohort between 1999 and 2009 with full maternal address at delivery and linked to the statewide congenital anomaly surveillance system (n = 2,234,138 births, 86,315 cases). We examined extraction-related exposures using tertiles of inverse distance-squared weighting within 5 km for drilling site count, gas production, oil production, and produced water. In adjusted logistic regression models, we calculated odds of any congenital anomaly and 10 specific organ sites using two comparison groups: 1) 5 km of future drilling sites that are not yet operating (a priori main models), and 2) 5-10 km of an active well.

RESULTS

Using the temporal comparison group, we find increased odds of any congenital anomaly in the highest tertile exposure group for site count (OR: 1.25; 95% CI: 1.21, 1.30), oil production (OR: 1.08; 95% CI: 1.04, 1.12), gas production (1.20; 95% CI: 1.17, 1.23), and produced water (OR: 1.17; 95% CI: 1.14, 1.20). However, associations did not follow a consistent exposure-response pattern across tertiles. Associations are highly attenuated, but still increased, with the spatial comparison group in the highest tertile exposure group. Cardiac and circulatory defects are strongly and consistently associated with all exposure metrics.

SIGNIFICANCE

Increased odds of congenital anomalies, particularly cardiac and circulatory defects, were associated with exposures related to oil and gas extraction in this large population-based study. Future research is needed to confirm findings, examine specific exposure pathways, and identify potential avenues to reduce exposures among local populations.

IMPACT

About 5% of the U.S. population (~17.6 million people) resides within 1.6 km of an active oil or gas extraction site, yet the influence of this industry on population health is not fully understood. In this analysis, we examined associations between oil and gas extraction-related exposures and congenital anomalies by organ site using birth certificate and congenital anomaly surveillance data in Texas (1999-2009). Increased odds of congenital anomalies, particularly cardiac and circulatory defects, were associated with exposures related to oil and gas extraction in this large population-based study. Future research is needed to confirm these findings.

Maternal proximity to mountain-top removal mining and birth defects in Appalachian Kentucky, 1997–2003

Extraction of coal through mountaintop removal mining (MTR) alters many dimensions of the landscape. Explosive blasts, exposed rock, and coal washing have the potential to pollute air and water. Previous research suggests that infants born to mothers living in areas with MTR have a higher prevalence of birth defects. In this cross-sectional study, we further examine the relationship between MTR activity and several types of birth defects. Maternal exposure to MTR was assessed using remote sensing data from Skytruth, which captures MTR activity in the Central Appalachian region of the United States. Active MTR area was quantified within a five-kilometer buffer surrounding geocoded maternal address captured on birth records for live births to Appalachian Kentucky mothers between 1997 and 2003 (N = 95,581). We assigned high, medium, and low exposure based on the tertile of total MTR area within 5-km, and births with no MTR within this buffer were assigned zero exposure. The presence or absence of a birth defect grouped into six major organ systems was identified using birth records alone. Finally, we applied conditional multiple imputation for variables with missing values before conducting separate multivariable log-binomial regression models for each birth defect group. Prevalence ratio (PR) estimates were adjusted for individual level covariates from birth records. The prevalence of gastro-intestinal defects was significantly higher in birth records with high and low active MTR exposure compared to records with no exposure. (High exposure: PR = 1.99, 95% CI = 1.14–3.47; low exposure PR = 1.88, 95% CI = 1.06–3.31). This study supports some of the existing findings of previous ecological studies. Research addressing the relationship between gastro-intestinal birth defects and MTR coal mining is warranted but should carefully consider temporal dimensions of exposure.

Validity of diagnosis and procedure codes for identifying neural tube defects in infants

PURPOSE

The use of validated criteria to identify birth defects in electronic healthcare databases can avoid the cost and time-intensive efforts required to conduct chart reviews to confirm outcomes. This study evaluated the validity of various case-finding methodologies to identify neural tube defects (NTDs) in infants using an electronic healthcare database.

METHODS

This analysis used data generated from a study whose primary aim was to evaluate the association between first-trimester maternal prescription opioid use and NTDs. The study was conducted within the Medication Exposure in Pregnancy Risk Evaluation Program. A broad approach was used to identify potential NTDs including diagnosis and procedure codes from inpatient and outpatient settings, death certificates and birth defect flags in birth certificates. Potential NTD cases were chart abstracted and confirmed by clinical experts. Positive predictive values (PPVs) and 95% confidence intervals (95% CI) are reported.

RESULTS

The cohort included 113 168 singleton live-born infants: 55 960 infants with opioid exposure in pregnancy and 57 208 infants unexposed in pregnancy. Seventy-three potential NTD cases were available for the validation analysis. The overall PPV was 41% using all diagnosis and procedure codes plus birth certificates. Restricting approaches to codes recorded in the infants' medical record or to birth certificate flags increased the PPVs (72% and 80%, respectively) but missed a substantial proportion of confirmed NTDs.

CONCLUSIONS

Codes in electronic healthcare data did not accurately identify confirmed NTDs. These results indicate that chart review with adjudication of outcomes is important when conducting observational studies of NTDs using electronic healthcare data.

Impact evaluation of Zika epidemic on congenital anomalies registration in Brazil: An interrupted time series analysis

This study aimed to assess the impact of the Zika epidemic on the registration of birth defects in Brazil. We used an interrupted time series analysis design to identify changes in the trends in the registration of congenital anomalies. We obtained monthly data from Brazilian Live Birth Information System and used two outcome definitions: 1) rate of congenital malformation of the brain and eye (likely to be affected by Zika and its complications) 2) rate of congenital malformation not related to the brain or eye unlikely to be causally affected by Zika. The period between maternal infection with Zika and diagnosis of congenital abnormality attributable to the infection is around six months. We therefore used September 2015 as the interruption point in the time series, six months following March 2015 when cases of Zika started to increase. For the purposes of this analysis, we considered the period from January 2010 to September 2015 to be "pre-Zika event," and the period from just after September 2015 to December 2017 to be "post-Zika event." We found that immediately after the interruption point, there was a great increase in the notification rate of congenital anomalies of 14.9/10,000 live births in the brain and eye group and of 5.2/10,000 live births in the group not related with brain or eye malformations. This increase in reporting was in all regions of the country (except in the South) and especially in the Northeast. In the period "post-Zika event", unlike the brain and eye group which showed a monthly decrease, the group without brain or eye malformations showed a slow but significant increase (relative to the pre-Zika trend) of 0.2/10,000 live births. These findings suggest an overall improvement in the registration of birth malformations, including malformations that were not attributed to Zika, during and after the Zika epidemic.

Trends, correlates, and survival of infants with congenital diaphragmatic hernia and its subtypes

OBJECTIVE

To identify the live-birth prevalence, trends, correlates, and neonatal and 1-year survival rates of congenital diaphragmatic hernia.

METHODS

Using a population-based, retrospective cohort study design, we examined 1,025 cases of congenital diaphragmatic hernia from the 1998-2012 Florida Birth Defects Registry. We used Poisson and joinpoint regression models to compute prevalence ratios and temporal trends, respectively. Kaplan-Meier survival curves and Cox proportional hazards regression were used to describe neonatal and 1-year survival and estimate hazard ratios representing the predictors of infant survival.

RESULTS

The birth prevalence of congenital diaphragmatic hernia was 3.19 per 10,000 live births (95% confidence interval [CI]: 3.00-3.39); there was a 4.2% yearly increase among multiple cases only. Among all cases, maternal education less than high school (prevalence ratio: 1.25, 95% CI: 1.02-1.53), high school/associate degree/GED (prevalence ratio: 1.15, 95% CI: 1.01-1.32), multiple birth (prevalence ratio: 1.38, 95% CI: 1.05-1.81), and male sex (prevalence ratio: 1.18, 95% CI: 1.05-1.32) were associated with increased risk for congenital diaphragmatic hernia. The 24-hr, neonatal, and 1-year survival rates were 93.6%, 79.8%, and 71.2%, respectively. The highest hazard ratio of 17.87 (95% CI: 1.49-213.82) was observed for neonatal mortality among cases associated with chromosomal anomalies and born <37 weeks at < 1,500 g. Among isolated cases, multiple birth (hazard ratio: 0.41, 95% CI: 0.20-0.86) was associated with decreased 1-year mortality.

CONCLUSION

Low maternal education and multiple birth may be linked to congenital diaphragmatic hernia. The trends in prevalence, epidemiologic correlates, and predictors of early survival can differ between congenital diaphragmatic hernia subtypes-isolated, multiple, and chromosomal.© 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Maternal Chlamydia infection during pregnancy among younger mothers and risk of gastroschisis in singleton offspring

BACKGROUND

Prevalence of gastroschisis has been increasing in the United States (US) since 1980s. Genital infection with Chlamydia has also been increasing in prevalence, particularly among younger women. The etiology of gastroschisis is unknown. Ongoing research suggests multiple causal factors may be involved, including Chlamydia infection in mothers during pregnancy.

METHODS

Using birth certificate data from 2014 US vital records, we conducted a population-based case-control study to examine the association between prenatal Chlamydia exposure in young women (16-25 years of age) and gastroschisis in singleton offspring. Cases consisted of live births with gastroschisis, and controls had no major birth defects reported in their birth certificate. Logistic regression analysis was used to estimate crude and adjusted odds ratios (cOR and aOR) and 95% confidence intervals (CI).

RESULTS

There were 809 cases (95.6% were isolated cases) and 1,260,293 controls. Chlamydia during pregnancy was reported in 4.5% of case and 3.6% control mothers (p = .21). Case mothers were significantly more likely to be younger (16-20 years of age) at the time of delivery compared to control mothers (p < .0001). We found no significant association between Chlamydia infection during pregnancy and gastroschisis (cOR = 1.24; 95% CI = 0.89-1.73 and aOR = 1.06; 95% CI: 0.66-1.70).

CONCLUSION

With the caveat of possible misclassification of exposure and outcome variables in birth certificate data, we found no significant association between prenatal exposure to Chlamydia and gastroschisis in the offspring born to younger mothers. Future studies should refine measures by focusing on relevant risk period and biomarkers.

A quality assessment of reporting sources for microcephaly in Utah, 2003 to 2013

BACKGROUND

Obtaining accurate microcephaly prevalence is important given the recent association between microcephaly and Zika virus. Assessing the quality of data sources can guide surveillance programs as they focus their data collection efforts. The Utah Birth Defect Network (UBDN) has monitored microcephaly by data sources since 2003. The objective of this study was to examine the impact of reporting sources for microcephaly surveillance.

METHODS

All reported cases of microcephaly among Utah mothers from 2003 to 2013 were clinically reviewed and confirmed. The UBDN database was linked to state vital records and hospital discharge data for analysis. Reporting sources were analyzed for positive predictive value and sensitivity.

RESULTS

Of the 477 reported cases of microcephaly, 251 (52.6%) were confirmed as true cases. The UBDN identified 94 additional cases that were reported to the surveillance system as another birth defect, but were ultimately determined to be true microcephaly cases. The prevalence for microcephaly based on the UBDN medical record abstraction and clinical review was 8.2 per 10,000 live births. Data sources varied in the number and accuracy of reporting, but a case was more likely to be a true case if identified from multiple sources than from a single source.

CONCLUSION

While some reporting sources are more likely to identify possible and true microcephaly cases, maintaining a multiple source methodology allows for more complete case ascertainment. Surveillance programs should conduct periodic assessments of data sources to ensure their systems are capturing all possible birth defects cases. Birth Defects Research (Part A) 106:983-988, 2016. © 2016 Wiley Periodicals, Inc.

Evaluation of the Sensitivity and Accuracy of Birth Defects Indicators on the 2003 Revision of the U.S. Birth Certificate: Has Data Quality Improved?

BACKGROUND

The 2003 revision of the U.S. Birth Certificate was restricted to birth defects readily identifiable at birth. Despite being the lone source of birth defects cases in some studies, we lack population-based information on the quality of birth defects data from the most recent revision of the birth certificate.

METHODS

We linked birth certificate data to confirmed cases from the Florida Birth Defects Registry (FBDR) to assess the sensitivity and positive predictive value (PPV) of birth defects indicators on the birth certificate. Descriptive statistics and log-binomial regression were used to examine variation in data quality measures by defect type and other characteristics. We also evaluated the contribution of birth certificates as a case ascertainment source for the FBDR.

RESULTS

Sensitivity of the birth certificate was poor (19.1%) with variation across defects ranging from 55% for anencephaly and 54% for gastroschisis, to <10% for other defects. PPV was better (87.1%) and ranged from >93% for orofacial clefts and gastroschisis to <55% for anencephaly and limb reduction defects. We also observed variation in data quality across maternal, infant, and hospital characteristics. Of cases identified by the birth certificate and not any other FBDR data source, 54.9% were false-positive diagnoses.

CONCLUSIONS

Efforts to restrict the 2003 revision of the birth certificate to defects identifiable at birth have not improved the likelihood that birth certificates will identify infants born with those defects. We do not recommend the use of birth certificates as a source of birth defects data without case verification strategies.

Maternal Chlamydia Infection During Pregnancy and Risk of Cyanotic Congenital Heart Defects in the Offspring

OBJECTIVES

Genital Chlamydia is a common bacterial sexually-transmitted infection among reproductive aged women, particularly younger populations. Cyanotic congenital heart defects (CCHDs) constitute about one quarter of all cardiac malformations at birth, and are associated with high rate of morbidity and mortality. Epidemiological research on the association between maternal Chlamydia during pregnancy and CCHDs in the offspring is lacking.

METHODS

Using data from the 2012 United States birth certificates, we examined the association between CCHDs and prenatal exposure to Chlamydia among live singleton births with CCHDs (n = 2487) and unaffected singleton births (n = 3,334,424). We estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) using unconditional logistic regression analysis for all CCHDs combined, and isolated CCHDs (without other major congenital malformations).

RESULTS

Overall 1.7% of case and 1.7% of control women reported having Chlamydia during their pregnancies. After controlling for potential confounders, we found a weak positive association between maternal Chlamydia during pregnancy and all CCHDs combined (aOR = 1.39; 95% CI 1.02-1.90). The positive association persisted for isolated CCHD cases, but with marginal significance (aOR = 1.34; 95% CI 0.96-1.74). Subgroup analyses for younger women showed an increased risk for CCHDs; however, the associations were not statistically significant.

CONCLUSIONS

Maternal exposure to Chlamydia during pregnancy was weakly associated with a higher risk of CCHDs in the offspring. The finding should be interpreted with caution due to limitations of birth certificate data. Future studies using more robust data sources are warranted to further study the association between maternal Chlamydia during pregnancy and CCHDs in the offspring.

Gastroschisis: epidemiology and mode of delivery, 2005-2013

BACKGROUND

Gastroschisis is a severe congenital anomaly the etiology of which is unknown. Research evidence supports attempted vaginal delivery for pregnancies complicated by gastroschisis in the absence of obstetric indications for cesarean delivery.

OBJECTIVE

The objectives of the study evaluating pregnancies complicated by gastroschisis were to determine the proportion of women undergoing planned cesarean vs attempted vaginal delivery and to provide up-to-date epidemiology on the risk factors associated with this anomaly.

STUDY DESIGN

This population-based study of US natality records from 2005 through 2013 evaluated pregnancies complicated by gastroschisis. Women were classified based on whether they attempted vaginal delivery or underwent a planned cesarean (n = 24,836,777). Obstetrical, medical, and demographic characteristics were evaluated. Multivariable log-linear regression models were developed to determine the factors associated with the mode of delivery. Factors associated with the occurrence of the anomaly were also evaluated in log-linear models.

RESULTS

Of 5985 pregnancies with gastroschisis, 63.5% (n = 3800) attempted vaginal delivery and 36.5% (n = 2185) underwent a planned cesarean delivery. The rate of attempted vaginal delivery increased from 59.7% in 2005 to 68.8% in 2013. Earlier gestational age and Hispanic ethnicity were associated with lower rates of attempted vaginal delivery. Factors associated with the occurrence of gastroschisis included young age, smoking, high educational attainment, and being married. Protective factors included chronic hypertension, black race, and obesity. The incidence of gastroschisis was 3.1 per 10,000 pregnancies and did not increase during the study period.

CONCLUSION

Attempted vaginal delivery is becoming increasingly prevalent for women with a pregnancy complicated by gastroschisis. Recommendations from the research literature findings may be diffusing into clinical practice. A significant proportion of women with this anomaly still deliver by planned cesarean, suggesting further reduction of surgical delivery for this anomaly is possible.

Maternal and infant characteristics: differences and similarities between the Nordic countries and the US

Background

Data from the Nordic health care registers have been of great value in perinatal epidemiological research. It has been assumed that findings from the Nordic population (Denmark, Finland, Iceland, Norway, and Sweden) are applicable to other populations as well, including the population of the US.

Objective

To describe and compare maternal and infant characteristics between the Nordic and the American populations as recorded in the official statistics.

Materials and methods

This population-based study included data on all females who gave birth and their infants in the Nordic countries and the US. The data were obtained from the US National Center for Health Statistics and the official statistics data for the Nordic countries. The data from all six countries included births from 2006 to 2010.

Results

The mean maternal age at delivery was lower in the US than in the Nordic countries (27.5 vs 30.3 years). Cesarean sections (32.2% vs 17.9%), low birth weight (8.2% vs 4.8%), and preterm birth (12.3% vs 5.9%) were more common in the US than in the Nordic countries. Smoking during early pregnancy was slightly less common in the US compared with Nordic countries (9.8% vs 11.2%). Restricting the data from the US to females with a university degree, characteristics such as age at delivery, birth weight, and preterm deliveries were more in alignment with the Nordic data.

Conclusion

There are differences in some key maternal and neonatal characteristics between the Nordic countries and the US. However, some characteristics are related to socioeconomic status, suggesting that the Nordic data seem to be applicable to the part of the population in the US with a higher socioeconomic status.

Construction and Characterization of a Population-Based Cohort to Study the Association of Anesthesia Exposure with Neurodevelopmental Outcomes

Exposure to general anesthesia at an early age has been associated with adverse neurodevelopmental outcomes in both animal and human studies, but some of these studies employed anesthetic agents that are no longer in clinical use. In this manuscript, we describe the methods used to construct a new population-based study cohort to study the association between early anesthetic exposure and subsequent neurodevelopmental outcomes. A birth cohort of all children born in Olmsted County, MN from January 1, 1996 to December 31, 2000 was identified. For each, school enrollment status in the Independent School District (ISD) 535 at age 5 or 6 and all episodes of anesthetic exposure before age 3 were identified. A study cohort was created by matching children enrolled in ISD 535 based on the propensity of receiving general anesthesia. Three analyses were performed to characterize the study cohort by comparing the birth and parental information, comorbidities, and socioeconomic status. The first analysis compared the characteristics of birth cohort children who were and were not enrolled in ISD 535. The second analysis evaluated the success of the propensity matching schemes in creating groups of children that were similar in measured characteristics except for anesthesia exposure. The third analysis compared the characteristics of children with anesthesia exposures who were and were not included in the final cohort based on propensity matching. Results of these analyses demonstrate only slight differences among the comparison groups, and therefore these are unlikely to compromise our future analysis of anesthetic exposure and neurodevelopmental outcomes.

Comparison of birth certificates and hospital-based birth data on pregnancy complications in Los Angeles and Orange County, California

Background

The incidence of both gestational diabetes mellitus and preeclampsia is on the rise; however, these pregnancy complications may not be systematically reported. This study aimed to examine differences in reporting of preeclampsia and gestational diabetes between hospital records and birth certificate data, and to determine if such differences vary by maternal socioeconomic status indicators.

Methods

We obtained over 70,000 birth records from 2001 to 2006 from the perinatal research database of the Memorial Care system, a network of four hospitals in Los Angeles and Orange Counties, California. Memorial birth records were matched to corresponding state birth certificate records and analyzed to determine differential rates of reporting of preeclampsia and diabetes. Additionally, the influence of maternal socioeconomic factors on the reported incidence of such adverse pregnancy outcomes was analyzed. Socioeconomic factors of interest included maternal education levels, race, and type of health insurance (private or public).

Results

It was found that the birth certificate data significantly underreported the incidence of both preeclampsia (1.38 % vs. 3.13 %) and diabetes (1.97 % vs. 5.56 %) when compared to Memorial data. For both outcomes of interest, the degree of underreporting was significantly higher among women with lower education levels, among Hispanic women compared to Non-Hispanic White women, and among women with public health insurance.

Conclusion

The Memorial Care database is a more reliable source of information than birth certificate data for analyzing the incidence of preeclampsia and diabetes among women in Los Angeles and Orange Counties, especially for subpopulations of lower socioeconomic status.

Maternal residential exposure to agricultural pesticides and birth defects in a 2003 to 2005 North Carolina birth cohort

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 (<10(th) , 10-50(th) , 50-90(th) , and >90(th) 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.

Estimates of the live births, natural losses, and elective terminations with Down syndrome in the United States

The present and future live birth prevalence of Down syndrome (DS) is of practical importance for planning services and prioritizing research to support people living with the condition. Live birth prevalence is influenced by changes in prenatal screening technologies and policies. To predict the future impact of these changes, a model for estimating the live births of people with DS is required. In this study, we combine diverse and robust datasets with validated estimation techniques to describe the non-selective and live birth prevalence of DS in the United States from 1900-2010. Additionally, for the period 1974-2010, we estimate the impact of DS-related elective pregnancy terminations (following a prenatal diagnosis of DS) on the live births with DS. The live birth prevalence for DS in the most recent years (2006-2010) was estimated at 12.6 per 10,000 (95% CI 12.4-12.8), with around 5,300 births annually. During this period, an estimated 3,100 DS-related elective pregnancy terminations were performed in the U.S. annually. As of 2007, the estimated rates at which live births with DS were reduced as a consequence of DS-related elective pregnancy terminations were 30% (95% CI: 27.3-31.9) for the U.S. as a whole. Our results and our model provide data on the impact of elective pregnancy terminations on live births with DS and may provide a baseline from which future trends for live births with DS can be estimated.

Development and implementation of the first national data quality standards for population-based birth defects surveillance programs in the United States

Background

Population-based birth defects surveillance is a core public health activity in the United States (U.S.); however, the lack of national data quality standards has limited the use of birth defects surveillance data across state programs. Development of national standards will facilitate data aggregation and utilization across birth defects surveillance programs in the U.S.

Methods

Based on national standards for other U.S. public health surveillance programs, existing National Birth Defects Prevention Network (NBDPN) guidelines for conducting birth defects surveillance, and information from birth defects surveillance programs regarding their current data quality practices, we developed 11 data quality measures that focused on data completeness (n = 5 measures), timeliness (n = 2), and accuracy (n = 4). For each measure, we established tri-level performance criteria (1 = rudimentary, 2 = essential, 3 = optimal). In January 2014, we sent birth defects surveillance programs in each state, District of Columbia, Puerto Rico, Centers for Disease Control and Prevention (CDC), and the U.S. Department of Defense Birth and Infant Health Registry an invitation to complete a self-administered NBDPN Standards Data Quality Assessment Tool. The completed forms were electronically submitted to the CDC for analyses.

Results

Of 47 eligible population-based surveillance programs, 45 submitted a completed assessment tool. Two of the 45 programs did not meet minimum inclusion criteria and were excluded; thus, the final analysis included information from 43 programs. Average scores for four of the five completeness performance measures were above level 2. Conversely, the average scores for both timeliness measures and three of the four accuracy measures were below level 2. Surveillance programs using an active case-finding approach scored higher than programs using passive case-finding approaches for the completeness and accuracy measures, whereas their average scores were lower for timeliness measures.

Conclusions

This initial, nation-wide assessment of data quality across U.S. population-based birth defects surveillance programs highlights areas for improvement. Using this information to identify strengths and weaknesses, the birth defects surveillance community, working through the NBDPN, can enhance and implement a consistent set of standards that can promote uniformity and enable surveillance programs to work towards improving the potential of these programs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2223-2) contains supplementary material, which is available to authorized users.

Reassessing the impact of smoking on preeclampsia/eclampsia: are there age and racial differences?

OBJECTIVE

To investigate the association between cigarette use during pregnancy and pregnancy-induced hypertension/preeclampsia/eclampsia (PIH) by maternal race/ethnicity and age.

METHODS

This retrospective cohort study was based on the U.S. 2010 natality data. Our study sample included U.S. women who delivered singleton pregnancies between 20 and 44 weeks of gestation without major fetal anomalies in 2010 (n = 3,113,164). Multivariate logistic regression models were fit to estimate crude and adjusted odds ratios and the corresponding 95% confidence intervals.

RESULTS

We observed that the association between maternal smoking and PIH varied by maternal race/ethnicity and age. Compared with non-smokers, reduced odds of PIH among pregnant smokers was only evident for non-Hispanic white and non-Hispanic American Indian women aged less than 35 years. Non-Hispanic Asian/Pacific Islander women who smoked during pregnancy had increased odds of PIH regardless of maternal age. Non-Hispanic white and non-Hispanic black women 35 years or older who smoked during pregnancy also had increased odds of PIH.

CONCLUSION

Our study findings suggest important differences by maternal race/ethnicity and age in the association between cigarette use during pregnancy and PIH. More research is needed to establish the biologic and social mechanisms that might explain the variations with maternal age and race/ethnicity that were observed in our study.

United States birth weight reference corrected for implausible gestational age estimates

OBJECTIVES

To provide an updated US birth weight for gestational age reference corrected for likely errors in last menstrual period (LMP)-based gestational age dating, as well as means and SDs, to enable calculation of continuous and categorical measures of birth weight for gestational age.

METHODS

From the 2009-2010 US live birth files, we abstracted singleton births between 22 and 44 weeks of gestation with at least 1 nonmissing estimate of gestational age (ie, LMP or obstetric/clinical) and birth weight. Using an algorithm based on birth weight and the concordance between these gestational age estimates, implausible LMP-based gestational age estimates were either excluded or corrected by using the obstetric/clinical estimate. Gestational age- and sex-specific birth weight means, SDs, and smoothed percentiles (3rd, 5th, 10th, 90th, 95th, 97th) were calculated, and the 10th and 90th percentiles were compared with published population-based references.

RESULTS

A total of 7 818 201 (99% of eligible) births were included. The LMP-based estimate of gestational age comprised 85% of the dataset, and the obstetric/clinical estimate comprised the remaining 15%. Cut points derived from the current reference identified ∼10% of births as ≤10th and ≥90th percentiles at all gestational weeks, whereas cut points derived from previous US-based references captured variable proportions of infants at these thresholds within the preterm and postterm gestational age ranges.

CONCLUSIONS

This updated US-based birth weight for gestational age reference corrects for likely errors in gestational age dating and allows for the calculation of categorical and continuous measures of birth size.

Adjusting for multiple-misclassified variables in a study using birth certificates

PURPOSE

Birth certificates are a convenient source of population data for epidemiologic studies. It is well documented, however, that birth certificate data can be highly inaccurate. Nonetheless, studies based on birth certificates are routinely analyzed without accounting for sources of data errors. We focused on the association between maternal cigarette smoking and cleft lip and palate based on birth certificate data.

METHODS

We adjusted odds ratio estimates simultaneously for exposure and outcome misclassification. We also calculated odds ratios adjusted for exposure misclassification only and outcome misclassification only.

RESULTS

Adjustment for both maternal smoking during pregnancy and clefting resulted in adjusted odds ratios that ranged from less than 1.0 to much greater than the unadjusted estimate of 1.16, with most adjusted estimates outside of the 95% confidence limits (1.01, 1.33).

CONCLUSIONS

Because of the potentially large impact of birth certificate classification errors, we suggest that inferences from these or similar records employ quantitative methods for incorporating uncertainties caused by data errors.

The influence of misclassification bias on the reported rates of congenital anomalies on the birth certificates for West Virginia--a consequence of an open-ended query

BACKGROUND

Passive surveillance for congenital anomalies using birth certificates are generally considered to have biased reporting, though the sources of those biases are not well-known nor controlled for. We have analyzed the congenital anomaly reporting data for 418,385 live births in West Virginia (1990-2009) from the 1989 US standard birth certificate and have newly identified a particular source of bias.

METHODS

Congenital anomaly prevalence rates per 100 live births have been determined for both specified birth defects and for other congenital anomalies by county, by hospital, and by year. Extreme outliers were identified by z score. Text strings for "other congenital anomaly" reports recorded for 1998-2009 were assessed for information on congenital anomalies.

RESULTS

While rates for specified birth defects reported in checked-box format showed little variation, rates for "other congenital anomaly" collected in open-ended format showed much variation. Nearly half of the "other congenital anomaly" reports were for neonatal conditions rather than for major structural congenital anomalies. This misclassification alone had elevated the state-wide congenital anomaly reporting rate from 1.1 to 1.8% of live births. Geographic clustering and a temporal bulge in congenital anomaly reports disappeared after misclassified data were removed.

CONCLUSIONS

Data collected in checked-box format on specified birth defects showed consistent patterns over time and space, while data collected in open-ended format on "other congenital anomalies" showed an epidemiological pattern reflecting neonatal conditions rather than birth defects. The 2003 US standard birth certificate wisely limits data collection to specified birth defects using the checked-box format.

A comparison of two surveillance strategies for selected birth defects in Florida

OBJECTIVE

We linked data from two independent birth defects surveillance systems with different case-finding methods in an overlapping geographic area to assess Florida's suveillance of birth defects (e.g., neural tube defects, orofacial clefts, gastroschisis/omphalocele, and chromosomal defects), focusing on sensitivity and completeness of ascertainment measures.

METHODS

Live-born infants identified from each system born during 2003-2006 in a nine-county catchment area with specific birth defects were linked to birth certificates. Using the enhanced surveillance system as a gold standard, we calculated the sensitivity of the Florida Birth Defects Registry (FBDR) for identifying infants. Next, we used capture-recapture models to estimate the completeness of case ascertainment and the prevalence of each birth defect in the catchment area. We used multivariable logistic regression models with backward elimination to estimate adjusted odds ratios and 95% confidence intervals for factors significantly associated with the FBDR's failure to capture infants ultimately identified by enhanced surveillance.

RESULTS

The FBDR's sensitivity was 89.3%, and the overall completeness of ascertainment was estimated as 86.6%. Defect-specific sensitivity and completeness of ascertainment varied significantly by defect. The combined defect-specific sensitivity for all malformations under study was 86.6%; completeness of ascertainment ranged from 45.6% for anencephaly to 88.6% for Down syndrome, 87.9% for spina bifida without anencephaly, and 87.0% for orofacial clefts.

CONCLUSIONS

For the defects under study, the FBDR captured nearly nine of every 10 infants born with selected birth defects. However, the FBDR's ability to identify specific defects was both more limited and defect dependent with widely varying defect-specific sensitivities.

[Reliability of birth certificates as a source of information on congenital defects in the City of São Carlos, São Paulo, Brazil]

The reliability of the information on congenital defects listed in birth certificates of the Live Birth Information System (SINASC) in the City of São Carlos, São Paulo, Brazil, was evaluated. A descriptive study that reviewed all 15,249 birth certificates from 2003 to 2007 compared the data with information from medical records and death certificates. Errors in accuracy and precision, mainly related to the description of the anomaly when it was transcribed from medical records to the birth certificates, in addition to coding and the input to SINASC, diminished the reliability of the birth certificates as a source of information on congenital defects. The results suggested that the involvement of the Municipal Health Department is essential to improve SINASC, because this is the location of the coding and input system, and training of the professionals who fill out the birth certificates. With guidance on the importance and function of the birth certificates, SINASC can become an excellent monitoring and surveillance system for congenital defects.

Folic acid and human reproduction-ten important issues for clinicians

This article presents data on the current best evidence-based clinical practices and controversies surrounding folic acid supplementation/fortification for the prevention of neural tube defects (NTDs) during early pregnancy. Formatted as a series of ten clinical questions, answers and extensive discussion are provided for each point. We assess the history and evidence behind supplementation and fortification, racial/ethnic disparities in NTDs on a global scale, and present information on risk factors for NTDs other than dietary folic acid deficiency. Also discussed are public health challenges, including disparities in NTD rates, population-wide monitoring of NTDs, and tracking safety data in the post-fortification era. Emerging data are also reviewed regarding the role folic acid may play in malignant processes, cardiovascular disease, male fertility, and other medical conditions.

Surveillance of birth defects: Brazil and the US

The impacts of birth defects in the society have substantially increased over the last decades in countries where the reduction of infant mortality by other causes has occurred. Birth defects surveillance represents an important source of information for planning X health policies and resource allocation. In this article, we discuss the potential utilizations, methodology options, limitations, and policy issues related to birth defects surveillance. Also, the birth defects surveillance programs from US and Brazil are described and compared as an illustration of the development of surveillance systems in two countries with clearly dissimilar health systems and resource allocation for birth defects programs. Finally, we propose measures for the improvement of the existing systems in both countries focusing at the utilization of preexisting resources.

Sensitivity of birth certificate reports of birth defects in Atlanta, 1995-2005: effects of maternal, infant, and hospital characteristics

OBJECTIVES

We assessed variations in the sensitivity of birth defect diagnoses derived from birth certificate data by maternal, infant, and hospital characteristics.

METHODS

We compared birth certificate data for 1995-2005 births in Atlanta with data from the Metropolitan Atlanta Congenital Defects Program (MACDP). We calculated the sensitivity of birth certificates for reporting defects often discernable at birth (e.g., anencephaly, spina bifida, cleft lip, clubfoot, Down syndrome, and rectal atresia or stenosis). We used multivariable logistic regression models to examine associations with sociodemographic and hospital factors.

RESULTS

The overall sensitivity of birth certificates was 23% and ranged from 7% for rectal atresia/stenosis to 69% for anencephaly. Non-Hispanic black maternal race/ethnicity, less than a high school education, and preterm birth were independently associated with a lower probability of a birth defect diagnosis being reported on a birth certificate. Sensitivity also was lower for hospitals with > 1,000 births per year.

CONCLUSIONS

The underreporting of birth defects on birth certificates is influenced by sociodemographic and hospital characteristics. Interpretation of birth defects prevalence estimates derived from birth certificate reports should take these issues into account.

Confiabilidade dos dados do Sistema de Informações sobre Nascidos Vivos em Teresina, Estado do Piauí, Brasil - 2002

Este artigo tem como objetivo avaliar a confiabilidade dos dados do Sistema de Informações sobre Nascidos Vivos (SINASC) em Teresina, Piauí, no ano de 2002. Estudou-se a proporção de preenchimento e a concordância entre as variáveis do SINASC e dos registros hospitalares (SINASC-P), utilizando-se o índice kappa. As variáveis do SINASC apresentaram melhor qualidade de preenchimento (completude>90%) em relação às variáveis do SINASC-P (completude>74%). A concordância foi excelente (kappa>0,80) para as variáveis idade da mãe, estado civil, número de filhos nascidos vivos, tipo de parto, sexo e peso do recém-nascido. As variáveis número de filhos nascidos mortos, consultas pré-natal, escolaridade e duração da gestação apresentaram concordância, variando entre mínima e boa (0,20<kappa<0,80). O SINASC apresentou excelente qualidade de preenchimento e concordância média considerada boa (kappa=0,76). Recomenda-se melhorar a qualidade dos registros hospitalares e aprimorar a coleta de dados do SINASC em Teresina.

Qualidade da notificação de anomalias congênitas pelo Sistema de Informações sobre Nascidos Vivos (SINASC): estudo comparativo nos anos 2004 e 2007

Este estudo comparou a validade dos diagnósticos de anomalias congênitas do Sistema de Informações sobre Nascidos Vivos (SINASC), em oito hospitais distribuídos em sete municípios do Brasil, totalizando 27.945 nascidos vivos em 2004 e 25.905 em 2007. Além disso, descreveu ações específicas realizadas para o aprimoramento da qualidade dos dados desse campo. Para a análise da validade, foi utilizado o Estudo Colaborativo Latino-Americano de Malformações Congênitas (ECLAMC) como padrão-ouro. Em 2004, pelo menos 40% dos casos de anomalias congênitas eram subnotificados, situação que não foi modificada em 2007. Observou-se aumento significativo na sensibilidade somente em um hospital, de 56,9% para 96,8%. Em dois hospitais, houve diminuição significativa na sensibilidade, de 62,7% para 41,7% e de 66,5% para 32,2%. Os valores preditivos positivo e negativo e especificidade permaneceram acima de 80%. Apenas duas secretarias municipais de saúde e quatro hospitais fizeram algum tipo de ação específica para a melhoria do campo 34. Os resultados apontam para a necessidade de se investir na qualidade da informação sobre anomalias congênitas no SINASC.

Maternal dietary glycemic intake and the risk of neural tube defects

Both maternal diabetes and obesity have been associated with an increased risk of neural tube defects (NTD), possibly due to a sustained state of hyperglycemia and/or hyperinsulinemia. Data were collected in the Boston University Slone Birth Defects Study (a case-control study) from 1988 to 1998. The authors examined whether high dietary glycemic index (DGI) and high dietary glycemic load (DGL) increased the risk of NTDs in nondiabetic women. Mothers of NTD cases and nonmalformed controls were interviewed in person within 6 months after delivery about diet and other exposures. Odds ratios and 95% confidence intervals were estimated from logistic regression for high DGI (> or =60) and high DGL (> or =205), with cutpoints determined by cubic spline. Of 698 case mothers, 25% had high DGI and 4% had high DGL. Of 696 control mothers, 15% had high DGI and 2% had high DGL. After adjustment for sociodemographic factors and other dietary factors, the odds ratio for high DGI was 1.5 (95% confidence interval: 1.1, 2.0); for high DGL, it was 1.8 (95% confidence interval: 0.8, 4.0). Diets with proportionally high DGI or DGL may put the developing fetus at risk of an NTD, adding further evidence that hyperglycemia lies within the pathogenic pathway.

Serum levels of perfluorooctanoic acid and perfluorooctane sulfonate and pregnancy outcome

The authors examined the association of serum perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) with self-reported pregnancy outcome in Mid-Ohio Valley residents (2000-2006) highly exposed to PFOA. Data on 1,845 pregnancies within the 5 years preceding exposure measurement were analyzed for PFOA, and data on 5,262 pregnancies were analyzed for PFOS. Generalized estimating equations were used to calculate adjusted odds ratios and 95% confidence intervals. Neither PFOA nor PFOS showed any association with miscarriage or preterm birth. Preeclampsia was weakly associated with PFOA (adjusted odds ratio = 1.3, 95% confidence interval: 0.9, 1.9) and PFOS (adjusted odds ratio = 1.3, 95% confidence interval: 1.1, 1.7) exposures above the median. PFOA was not associated with an increase in low birth weight, but PFOS showed an increased risk above the median (adjusted odds ratio = 1.5, 95% confidence interval: 1.1, 1.9) and a dose-response gradient. Birth defects were weakly associated with PFOA exposures above the 90th percentile (adjusted odds ratio = 1.7, 95% confidence interval: 0.8, 3.6). This study identified modest associations of PFOA with preeclampsia and birth defects and of PFOS with preeclampsia and low birth weight, but associations were small, limited in precision, and based solely on self-reported health outcomes.

Challenges and priorities for surveillance of stillbirths: a report on two workshops

Stillbirths, those with and without birth defects, are an important public health topic. The National Center on Birth Defects and Developmental Disabilities at the Centers for Disease Control and Prevention conducted two workshops during April and July 2005. Both workshops explored the challenges of conducting surveillance of stillbirths. Workshop participants considered an approach that added the surveillance of stillbirths, those with and without birth defects, as part of existing population-based birth defects surveillance programs in Iowa and Atlanta. The workshops addressed three key aspects for expanding birth defects programs to conduct active, population-based surveillance on stillbirths: (1) case identification and ascertainment, (2) data collection, and (3) data use and project evaluation. Participants included experts in pediatrics, obstetrics, epidemiology, maternal-fetal medicine, perinatology and pediatric pathology, midwifery, as well as practicing clinicians and pathologists. Expanding existing birth defects surveillance programs to include information of stillbirths could potentially enhance the data available on fetal death reports and also could benefit such programs by improving the ascertainment of birth defects.

Quality of reporting on birth defects in birth certificates: case study from a Brazilian reference hospital

The aim of this study was to evaluate the coverage, validity and reliability of Brazil's Information System on Live Births (SINASC) for birth defects in a hospital in the city of Campinas (São Paulo State). The study population consisted of 2,823 newborn infants delivered in 2004 at the Women's Integrated Health Care Center (CAISM). A birth defect registry (ECLAMC) was used as the gold-standard. All birth defect cases reported at CAISM in 2004 (92 cases) were selected from SINASC data files. All 168 birth defect cases from the same city and year registered at ECLAMC were also retrieved. An underreporting of 46.8% was observed for all birth defects, and 36.4% when considering only the major birth defects. The ascertained sensitivity and specificity were, respectively, 54.2% and 99.8%. The reliability of three and four-digit ICD-10 coding for birth defects was 0.77 and 0.55 respectively (kappa statistic). These results suggest that information provided by birth certificates in Campinas still presents limitations when seeking to ascertain accurate estimates of the prevalence of birth defects, hence indicating the need for improvements in the SINASC database to enable it to portray birth defect prevalence at birth in this city.

The relationship between utilization of prenatal care and Down syndrome live births

OBJECTIVE

This study evaluated whether utilization of prenatal care, as measured by the Kessner index, affects the number of Down syndrome live births.

METHODS

A retrospective analysis of birth certificate data of Down syndrome live births comparing 1989 to 2001 by year, maternal age, gestational age at first prenatal visit, and adequacy of prenatal care according to Kessner categories of adequacy of prenatal care.

RESULTS

Down syndrome live births were inversely correlated with adequacy of prenatal care. Reductions in Down syndrome live births were seen in all categories of prenatal care in all age groups. In 2001 a minimum 30% reduction was seen in any category rising to a 58% reduction in women > or =35 years with adequate prenatal care. The largest reductions were seen in women > or =35 years of age.

CONCLUSIONS

Reductions in Down syndrome live births occurred in all age groups between 1989 and 2001. Utilization of prenatal care as measured by the Kessner index was associated with reductions in Down syndrome live births, with a greater reduction in women > or =35 years of age.

A case-control study of infant, maternal and perinatal characteristics associated with deformational plagiocephaly

Deformational plagiocephaly, an abnormal asymmetric flattening of infants' heads, is diagnosed in approximately 10% of infants. The prevalence of plagiocephaly has increased dramatically since 1992 when it was first recommended that infants be placed to sleep in a non-prone position to reduce the risk of sudden infant death syndrome. The authors conducted a case-control study to evaluate associations between plagiocephaly and perinatal characteristics. The authors assessed whether risk factors for plagiocephaly have changed since 1992. Cases were born 1987-2002 in Washington State and diagnosed with plagiocephaly at the Craniofacial Center at Seattle Children's Hospital. Risk factor information was abstracted from birth certificate and hospital discharge data and unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI). Cases (n = 2764) were more likely than controls (n = 13 817) to have been injured at birth (OR 1.4; 95% CI 1.2, 1.7) or diagnosed with a congenital anomaly (OR 2.0; 95% CI 1.8, 2.3). Cases were more likely to have been male, a twin, or small-for-gestational-age. This first large-scale, case-control study of risk factors for plagiocephaly in a U.S. population provides new evidence that birth injuries and congenital anomalies are associated with plagiocephaly risk.

A case control population-based study investigating smoking as a risk factor for gastroschisis in Utah, 1997-2005

BACKGROUND

Smoking in pregnancy increases the risk for many different adverse pregnancy outcomes, including birth defects. Gastroschisis, a birth defect most commonly associated with young maternal age has been associated with smoking, but findings are inconsistent. We assessed whether smoking increases the risk for gastroschisis using population-based data from Utah.

METHODS

Gastroschisis cases (n = 189) were identified from the Utah Birth Defect Network and all live births without birth defects (n = 423,499) occurring in Utah from January 1, 1997 through December 31, 2005 served as controls. Exposure data were derived from birth certificates and fetal death certificates and, for terminated pregnancies, the Utah Birth Defect Network.

RESULTS

Women who smoked during the first trimester of pregnancy had an increased risk of gastroschisis (OR 1.6; 95% CI: 1.1, 2.3) after adjusting for maternal age and preconception BMI. Discordance between birth certificate data and data from structured interviews increased exposure prevalence from 16.9 to 22.2% for case mothers and 7.4 to 13.2% for control mothers. Accounting for this misclassification, the crude OR decreased by 24%, 1.9 (1.3, 2.7).

CONCLUSIONS

Though first trimester cigarette smoking was reported on birth certificates by more mothers of gastroschisis cases than controls, adjustment for confounders (maternal age and preconception BMI) and smoking misclassification suggests the association is weak. Despite a decrease in smoking prevalence among all women of childbearing years in Utah between 1997 and 2005, the prevalence of gastroschisis has not followed a similar trend.

Characteristics of 2733 cases diagnosed with deformational plagiocephaly and changes in risk factors over time

OBJECTIVES

To describe infant and maternal characteristics among infants with plagiocephaly and to quantify time trends in potential risk factors for plagiocephaly.

DESIGN

Case-only study. We described the characteristics of individuals born between 1987 and 2002. We also compared characteristics of individuals born from 1987 through 1990, before the American Academy of Pediatrics 1992 sleep-position recommendations, with those of individuals born from 1991 to 2002.

SETTING

Children's Craniofacial Center at Children's Hospital and Regional Medical Center in Seattle, Washington.

PARTICIPANTS

Subjects included 2733 infants diagnosed with deformational plagiocephaly or brachycephaly before 18 months of age who were born from 1987 to 2002.

MAIN OUTCOME MEASURE

Descriptive statistics, odds ratios, and 95% confidence intervals.

RESULTS

Among individuals born from 1991 to 2002, 91.6% had occipital-only flattening, 17.2% were brachycephalic, 67.7% were boys, and 9.9% were multiple birth infants. As compared with individuals born from 1987 through 1990, those born from 1991 to 2002 were more apt to be a multiple birth (odds ratio [OR] 3.4, 95% confidence interval [CI]: 0.8, 14.1) and to have a mother > or =35 years of age (OR, 3.2; 95% CI, 1.4 to 7.3); they were hospitalized less commonly at birth for 4 or more days (OR, 0.02; 95% CI, 0.01 to 0.06).

CONCLUSIONS

Several risk factors for plagiocephaly were more common among individuals born after the 1992 American Academy of Pediatrics sleep-position recommendations. These results are consistent with the explanation that supine sleeping modifies the association between such risk factors and plagiocephaly. Further studies with a control group are needed to validate this conclusion.

Positive predictive value of computerized records for major congenital malformations

PURPOSE

To assess the positive predictive value of computerized records in a linked database of vital records and infant claims, with medical record confirmation to detect congenital malformations in a Medicaid population.

METHODS

Study subjects were selected from cases identified for three studies of congenital malformations in the Tennessee Medicaid (TennCare) population including 173 827 (studies 1 and 2) and 519 465 (study 3) mother/infant pairs. Possible malformations were identified from computerized databases of birth certificates linked with maternal and infant claims. Medical records were reviewed for all possible congenital malformations and positive predictive values were calculated for each data source and for each malformation.

RESULTS

Among 1430 potential congenital malformations identified from either birth certificates or inpatient claims, 67.7% were confirmed by medical record review. The positive predictive value varied considerably depending on the data source and the organ system. For example, cardiac defects had a very low positive predictive value when identified from birth certificates, and somewhat higher positive predictive value when identified from inpatient claims. Orofacial defects had 90.9% positive predictive value from birth certificates and inpatient claims. Requiring evidence of a diagnostic or therapeutic procedure increased the positive predictive value to >90% for specific defects, but substantially reduced the number of included cases.

CONCLUSIONS

Depending on the defect, computerized claims data linked to vital records offer opportunities for identifying birth defects in populations of vulnerable persons. However, for many defects, medical record confirmation is likely to be required to provide valid identification of malformation occurrence.

JC, Gama SGND, Cunha CBD, Theme Filha MM. Confiabilidade das informações das declarações de nascido vivo com registro de defeitos congênitos no Município do Rio de Janeiro, Brasil, 2004

Avaliou-se a confiabilidade das informações sobre defeitos congênitos contidas nas declarações de nascido vivo do Sistema de Informações sobre Nascidos Vivos (SINASC) no Município do Rio de Janeiro, Brasil, no ano de 2004 comparando-as com os prontuários hospitalares destas crianças e de suas mães na internação para o parto. Após a seleção de 24 maternidades do SUS, os tipos de defeitos congênitos constantes nos prontuários foram transcritos em formulários de coleta próprios, codificados com base na CID-10 e comparados com os arquivos do SINASC. Verificou-se uma maior freqüência de defeitos congênitos dos sistemas osteomuscular e nervoso central e percentual de concordância acima de 50% nos aparelhos digestivo, urinário e osteomuscular, órgãos genitais e de anomalias cromossômicas. O kappa ajustado pela prevalência variou conforme as análises para 2 ou 3 dígitos da CID-10, com melhores resultados nos aparelhos osteomuscular, genito-urinário, digestivo e as anomalias cromossômicas e os piores nos sistemas nervoso central e cárdio-circulatório, malformações congênitas da face, olhos pescoço e orelhas e fendas lábio-palatinas. Os resultados encontrados são insatisfatórios e apontam para a necessidade de qualificação do pessoal envolvido no preenchimento das declarações assim como a padronização da codificação dos defeitos congênitos.

Fetal death certificates as a source of surveillance data for stillbirths with birth defects

OBJECTIVE

We assessed fetal death certificates (FDCs) as a source of surveillance for stillbirths with birth defects by linkage with data from the Metropolitan Atlanta Congenital Defects Program (MACDP), a population-based birth defects surveillance system.

METHODS

Stillbirths with defects in MACDP were identified from 1994 through 2002 and linked to FDCs. Sensitivity of FDCs for capturing stillbirths with defects was estimated, and predictors for a case being reported were assessed. Concordance for selected variables from each data source was evaluated. RESILTS: Two hundred twenty-four of 257 stillbirths with birth defects in MACDP were linked to an FDC (linkage rate = 87.2%; 95% confidence interval [CI] 82.4, 91.0). Stillbirths of non-Hispanic black and Hispanic/other mothers were more likely to be issued an FDC (odds ratio [OR] = 5.6 [95% CI 1.9, 17.0] and 14.0 [95% CI 1.7, 114.0], respectively). Cases undergoing autopsy were more likely to be issued an FDC (OR = 3.2; 95% CI 1.1, 8.7). Performance of an amniocentesis was poorly recorded on FDCs. The sensitivity and positive predictive value of FDCs for selected classes of defects ranged from 10% to 70% and 25% to 93%, respectively.

CONCLUSIONS

Compared to FDCs, MACDP's active case identification improves the ascertainment of stillbirths with birth defects and the quality of certain recorded data.