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Infants born extremely premature (EP) (28 weeks gestational age) are at high risk of complications, particularly bronchopulmonary dysplasia (BPD), which can develop into chronic lung disease (CLD).The burden of respiratory complications in EP infants up to 2 years corrected age (CA) was evaluated using real-world data from the US Medicaid program. Data recorded between 1997 and 2018 on EP infants without major congenital malformations were collected from Medicaid records of six states. EP infants were divided into three cohorts: BPD, CLD, and without BPD or CLD. The incidence of respiratory conditions, respiratory medication use, and healthcare resource utilization were compared between the BPD cohort and CLD cohort versus the cohort without BPD or CLD, using unadjusted and adjusted generalized linear models.A total of 4462 EP infants were identified (17.4% of all premature infants in the database). Of these, BPD and CLD were diagnosed in 61.9% and 72.1%, respectively, and 14.5% were diagnosed with neither BPD nor CLD. Compared with infants without BPD or CLD, infants with BPD or CLD had more complications and a longer length of birth hospitalization stay. Respiratory distress syndrome was the most frequently reported complication (94.6%, 92.5%, and 82.3% of EP infants in the BPD, CLD, and without BPD or CLD cohorts, respectively). After the birth hospitalization, respiratory conditions, respiratory medication use, and incidence rates of rehospitalizations, emergency room visits, and outpatient visits were higher for infants with BPD or CLD. Rehospitalization occurred in 50.5%, 51.6%, and 27.3% of EP infants with BPD, CLD, or without BPD or CLD, respectively; most hospitalizations occurred for respiratory-related reasons.In this analysis of a large population of EP infants up to 2 years CA, respiratory conditions were prevalent after the birth hospitalization and were associated with high rates of medication and healthcare resource utilization.

Approximately 5% of global preterm births are extremely premature (EP), defined as occurring at less than 28 weeks gestational age. Advances in care have led to an increase in the survival of EP infants during the neonatal period. However, EP infants have a higher risk of developing complications such as bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH), and retinopathy of prematurity (ROP). BPD and other respiratory morbidities are particularly prevalent among this population. To understand the healthcare resource utilization (HRU) of EP infants in the United States, the clinical and economic burden of extreme prematurity was examined in this retrospective study of data extracted from electronic medical records in the Kaiser Permanente Northern California (KPNC) health system. The analysis included data from EP infants live-born between January 1997 and December 2016, and focused on complications and HRU up to 3 years corrected age (CA), covering the period up to December 2018. Stillbirths, infants born at 1 year and ≤2 years, and >2 years and ≤3 years CA). Analysis of HRU included hospital readmissions, ambulatory visits, and emergency room (ER) visits. A total of 2154 EP births (0.32% of total live births and 4.0% of preterm births that met the inclusion/exclusion criteria) were analyzed. The prevalence of EP birth showed a declining trend over time. ROP was the most commonly recorded complication during the birth hospitalization (37.1% any stage; 2.9% Stages 3 and 4). BPD was recorded in 34.3% of EP infants. IVH (any grade) was recorded in 22.7% of EP infants (6.4% Grades III and IV). A majority (78.7%) of EP infants were diagnosed with at least one respiratory condition during the first year CA, the most common being pneumonia (68.9%); the prevalence of respiratory conditions decreased over the second and third years CA. During the first 3 years CA, the most common medications prescribed to children born EP were inhaled bronchodilators (approximately 30% of children); at least 15% of children received systemic corticosteroids and inhaled steroids during this period. During the first 3 years CA, at least one hospital readmission was recorded for 16.4% of children born EP; 57.1% of these readmissions were related to respiratory conditions. At least one ER visit was recorded for 33.8% of children born EP, for which 53.1% were due to a respiratory condition. Ambulatory visits were recorded for 54.2% of EP children, for which 82.9% were due to a respiratory condition. The short- and long-term clinical burden of EP birth was high. The onset of BPD, IVH, and ROP was common during the birth hospitalization for EP infants. Medication use, hospital readmission, and clinic visits (ER and ambulatory) occurred frequently in these children during the first 3 years CA, and were commonly due to respiratory conditions. Strategies prioritizing the reduction of risk and severity of respiratory conditions may alleviate the clinical burden of EP birth over the long term.

Objectives To conduct a systematic literature review to evaluate the global incidence of intraventricular hemorrhage grade 2–4 among extremely preterm infants. Methods We performed searches in MEDLINE and Embase for intraventricular hemorrhage and prematurity cited in English language observational studies published from May 2006 to October 2017. Included studies analyzed data from infants born at ≤28 weeks’ gestational age and reported on intraventricular hemorrhage epidemiology. Results Ninety-eight eligible studies encompassed 39 articles from Europe, 31 from North America, 25 from Asia, five from Oceania, and none from Africa or South America; both Europe and North America were included in two publications. The reported global incidence range of intraventricular hemorrhage grade 3–4 was 5–52% (Europe: 5–52%; North America: 8–22%; Asia: 5–36%; Oceania: 8–13%). When only population-based studies were included, the incidence range of intraventricular hemorrhage grade 3–4 was 6–22%. The incidence range of intraventricular hemorrhage grade 2 was infrequently documented and ranged from 5–19% (including population-based studies). The incidence of intraventricular hemorrhage was generally inversely related to gestational age. Conclusions Intraventricular hemorrhage is a frequent complication of extremely preterm birth. Intraventricular hemorrhage incidence range varies by region, and the global incidence of intraventricular hemorrhage grade 2 is not well documented.

Purpose To evaluate functional vision, general health status, and work productivity in individuals with and without dry eye disease (DED). Design Cross-sectional study. Methods S etting : General US population (2018). S tudy Population : Adults ≥18 years with (n = 1003) or without (n = 1006) self-reported DED. Main Outcome Measures: All respondents completed the National Eye Institute Visual Function Questionnaire (VFQ) and the EuroQol 5-dimensions 5-levels (EQ-5D-5L). All respondents with DED completed the eye dryness score (EDS) visual analogue scale, Ocular Comfort Index (OCI), and Work Productivity and Activity Impairment (WPAI) questionnaire. Half of respondents with DED completed the Impact of Dry Eye on Everyday Life (IDEEL) questionnaire; the other half completed the Dry Eye Questionnaire 5 (DEQ-5) and Standardized Patient Evaluation of Eye Dryness (SPEED), McMonnies, and Symptom Assessment in Dry Eye (SANDE) questionnaires. All analyses were descriptive. Results Respondents with DED reported more comorbidities, greater exposure to adverse environmental conditions, and lower (worse) mean (standard deviation) scores on the modified Rasch-scored 28-item VFQ (VFQ-28R) total score (68.8 [11.9] vs 81.2 [12.7]) and EQ-5D-5L (0.82 [0.13] vs 0.88 [0.14]) than respondents without DED. Respondents with DED and EDS ≥60 (highest discomfort) fared worse on OCI, VFQ-28R, and WPAI than respondents with DED and EDS Conclusions There is a substantial burden of DED on functional vision, general health status, and productivity; and further, these parameters appear to worsen with increasing EDS.

ObjectiveNeurodevelopmental impairment (NDI) is a major complication of extreme prematurity. This systematic review was conducted to summarize the worldwide long-term prevalence of NDI associated with extreme prematurity.MethodsEmbase and MEDLINE databases were searched for epidemiologic and observational/real-world studies, published in English between 2011 and 2016, reporting long-term prevalence of NDI (occurring from 1 year) among extremely preterm infants born at gestational age (GA) ≤28 weeks.ResultsOf 2406 articles identified through searches, 69 met the protocol NDI definition (24 North America, 25 Europe, 20 Rest of World). Prevalence of any severity NDI in North America was 8%–59% at 18 months to 2 years, and 11%–37% at 2–5 years; prevalence of moderate NDI in Europe was 10%–13% at 18 months to 2 years, 3% at 2–5 years, and 9%–19% at ≥5 years; prevalence of any NDI in Rest of World was 15%–61% at 18 months to 2 years, and 42% at 2–5 years (no North America/Rest of World studies reported any NDI at ≥5 years). A trend toward higher prevalence of NDI with lower GA at birth was observed.ConclusionsExtreme prematurity has a significant long-term worldwide impact on neurodevelopmental outcomes.

Infants born extremely preterm (28 weeks gestational age (GA)) face a high risk of neonatal mortality. Bronchopulmonary dysplasia (BPD) is the most common morbidity of prematurity.To evaluate the global incidence of BPD among infants born extremely preterm.A systematic review of the literature was conducted in Embase and MEDLINE (via PubMed) using a prespecified search strategy for BPD and prematurity. Observational studies published in English between 16 May 2006 and 16 October 2017 reporting on the occurrence of BPD in infants born28 weeks GA were included.Literature searches yielded 103 eligible studies encompassing 37 publications from Europe, 38 publications from North America, two publications from Europe and North America, 19 publications from Asia, one publication from Asia and North America, six publications from Oceania, and zero publications from Africa or South America. The reported global incidence range of BPD was 10-89% (10-73% in Europe, 18-89% in North America, 18-82% in Asia, and 30-62% in Oceania). When only population-based observational studies that defined BPD as requiring supplemental oxygen at 36 weeks postmenstrual age were included, the global incidence range of BPD was 17-75%. The wide range of incidences reflected interstudy differences in GA (which was inversely related to BPD incidence), birthweight, and survival rates across populations and institutions.BPD is a common health morbidity occurring with extremely preterm birth. Further study of factors that impact incidence, aside from low GA, may help to elucidate modifiable risks.

Preterm birth is a leading cause of infant mortality, particularly for those born extremely prematurely (EP;28 weeks' gestational age [GA]). Survivors are predisposed to complications such as bronchopulmonary dysplasia (BPD), chronic lung disease (CLD), intraventricular hemorrhage (IVH), and retinopathy of prematurity (ROP).To examine the epidemiology, complications, and mortality/survival among EP infants.Retrospective analysis of electronic medical records from the Kaiser Permanente Northern California database.EP infants live-born between 22 and28 weeks' GA from 1997 to 2016.Cumulative all-cause mortality/survival were analyzed and stratified by GA (22 to24, 24 to26, 26 to28 weeks), complications (BPD/CLD, IVH, ROP), and birth period (1997 to 2003, 2004 to 2009, 2010 to 2016). Cox proportional hazard models were constructed to assess the mortality risk associated with BPD/CLD or IVH.2154 EP infants were identified; of these, 916 deaths were recorded. Mortality was highest during the first 3 months (41.7 % cumulative mortality), and few were reported after 2 years (42.5 % cumulative mortality). Mortality decreased with higher GA and over more recent birth periods. BPD/CLD and IVH grade 3/4 were associated with increased mortality risk versus no complications (adjusted hazard ratios 1.41 and 1.78, respectively).The risk of mortality is high during the first few months of life for EP infants, and is even higher for those with BPD and IVH. Despite an overall trend toward increased survival for EP infants, strategies targeting survival of EP infants with these complications are needed.

ObjectivesTo compare sociodemographics and vision-related quality of life (QoL) of individuals with or without dry eye disease (DED); and to explore the impact of DED symptom severity on visual function, activity limitations and work productivity.DesignCross-sectional web-based survey.SettingGeneral UK population.ParticipantsAdults ≥18 years with (N=1002) or without (N=1003) self-reported DED recruited through email and screened.Main outcome measuresAll participants completed the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25), with six additional questions (items A3–A8), and the EuroQol 5 dimensions 5 levels. DED participants also completed Impact of Dry Eye on Everyday Life questionnaire, 5-item Dry Eye Questionnaire and the Standardised Patient Evaluation of Eye Dryness questionnaire along with the Ocular Comfort Index, Work Productivity and Activity Impairment and the Eye Dryness Score (EDS), a Visual Analogue Scale.ResultsBaseline demographic and clinical characteristics were similar in participants with versus without DED (mean age, 55.2 vs 55.0 years; 61.8% vs 61.0% women, respectively) based on recruitment targets. Scores were derived from NEI VFQ-25 using the new 28-item revised VFQ (VFQ-28R) scoring. Mean (SD) VFQ-28R scores were lower in participants with versus without DED, indicating worse functioning (activity limitations, 73.3 (12.3) vs 84.4 (12.3); socioemotional functioning, 75.3 (21.5) vs 90.3 (16.2); total score, 71.6 (12.8) vs 83.6 (12.6)). Higher percentages of problems/inability to do activities were observed among those with versus without DED. The impact of DED on visual function was worse for participants with more severe DED symptoms, as assessed by EDS. In addition, a higher EDS was associated with worse symptoms on common DED scales and a worse impact on work productivity.ConclusionsDED symptoms were associated with negative effects on visual function, activities and work productivity, whereas worse DED symptoms had a greater impact on vision-related QoL and work productivity.

Background We assessed sociodemographic and clinical factors that are associated with survival among infants with congenital diaphragmatic hernia (CDH). Methods Using data from the Metropolitan Atlanta Congenital Defects Program, we ascertained 150 infants born with CDH between 1979 and 2003 and followed via linkage with state vital records and the National Death Index. Kaplan–Meier survival probabilities and adjusted hazard ratios (HRs) were calculated for socioeconomic and clinical characteristics. Results Survival increased from 40 to 62% over the study period. White infants born before 1988 were 2.9 times less likely to survive than those born after 1988. Black infants' survival did not show significant improvement after 1988. White infants' survival was not significantly affected by poverty, whereas black infants born in higher levels of poverty were 2.7 times less likely to survive than black infants born in lower levels of neighborhood poverty. White infants with multiple major birth defects were 2.6 times less likely to survive than those with CDH alone. The presence of multiple defects was not significantly associated with survival among black infants. Conclusions Survival among infants and children with CDH has improved over time among whites, but not among blacks. Poverty is associated with lower survival among blacks, but not among whites. The presence of multiple defects is associated with lower survival among whites, but not among blacks. The differential effects of poverty and race should be taken into account when studying disparities in health outcomes. Birth Defects Research 109:816–823, 2017. © 2017 Wiley Periodicals, Inc.

PURPOSE To evaluate the clinical and economic burden of dry eye disease (DED) among affected patients in Germany. METHODS Adult patients (≥18 years) with ≥1 confirmed diagnosis of DED during the study period (2008-2015) were identified from the medical claims of ~3.6 million insured patients from Betriebskrankenkassen, a German statutory health insurance database. Prevalence (per 1000 patients) and incidence (per 1000 person-years at risk) were estimated, and demographic and clinical characteristics, treatment history (excluding over-the-counter tear supplements), healthcare resource use (HCRU) and costs were assessed. RESULTS In this population, the prevalence of DED increased from 20.24 in 2008 to 23.13 per 1000 patients in 2014. Overall incidence was 6.24 per 1000 person-years at risk (2008-2015). Prevalence and incidence increased with age and were higher in women. Mean age at index was 63.4 years (incident cohort, n = 35 026). The most common ocular comorbidity was cataract (48.5%), and ~36% of patients were dispensed a reimbursed DED-specific medication during the postindex period - most commonly, corticosteroids alone (13.2%) or in combination with anti-infectives (21.8%). HCRU was high in patients with DED, mostly due to comorbidities. HCRU and associated costs were highest in patients ≥60 years. Total costs during the postindex period were higher in the DED cohort than among matched controls (€117 million versus €107 million; p

Population-based cross-sectional survey in Ontario to estimate the 2016 prevalence of dry eye disease (DED) and associated risk factors among adults in Canada.We emailed the 5-Item Dry Eye Questionnaire (DEQ-5) to 124,469 Ontario adults (age ≥18 years) in the IQVIA E360 database, March-April 2017. Inclusion criteria were: ≥2 visits to an Ontario based clinic, ≥1 visits in the 1 year before the study; database record with email. DED was defined as a DEQ-5 score of6/22. The crude prevalence by age/sex of the Ontario sample was adjusted to the 2016 Canadian population (mean age 41.0 years, 51% female). Significance of DED risk factors (age, sex, selected diseases/medical conditions and medications) was evaluated by logistic regression analysis.Of the 5163 (4.1%) patients who completed the survey (59.5% female, median age, 46 years; 40.4% male, 56 years), 1135 respondents reported DED. Prevalence increased with age (p 0.05) and was highest among those aged 55-64 years (24.7%; 95% CI, 22.1-27.3%) and lowest among those aged 25-34 years (18.4%; 95% CI, 15.9-21.0%). Prevalence was significantly higher (p 0.001) among women (24.7%; 95% CI, 23.2-26.2%) than men (18.0%; 95% CI, 16.4-19.7%). Other risk factors were not significant. The age-/sex-adjusted Canadian DED prevalence estimate from this sample was 21.3% (95% CI, 19.8-23.2%), corresponding to ∼6.3 million people.Based on the Ontario sample, we estimate that6 million Canadian adults may have DED, and that older people and females are more likely to be affected.

Background Sanfilippo syndrome (mucopolysaccharidosis [MPS] III subtypes A, B, C, and D) is a rare autosomal recessive inherited metabolic disorder that causes progressive neurocognitive degeneration. This systematic literature review was undertaken to compile and assess published epidemiological data, including various frequency measures and geographical variation on Sanfilippo syndrome. Methods The following databases were systematically searched for terms related to Sanfilippo syndrome epidemiology: Medline, Embase, Cochrane Database of Systematic Reviews, Academic Search Complete, Cumulative Index to Nursing and Allied Health Literature, and the Centre for Reviews and Dissemination. Qualitative synthesis of research findings was performed. Results Of 2794 publications found in the initial search, 116 were deemed eligible after title and abstract screening. Following full-text review, 46 papers were included in the qualitative synthesis. Results of this systematic literature review indicate that lifetime risk at birth ranges from 0.17–2.35 per 100,000 live births for all 4 subtypes of MPS III together, and from 0.00–1.62 per 100,000 live births for the most frequent subtype, MPS IIIA. Conclusion All 4 subtypes of MPS III are exceptionally rare, but they each have devastating effects on children. Higher-quality epidemiological data are needed to appropriately target resources for disease research and management. Electronic supplementary material The online version of this article (10.1186/s13023-018-0796-4) contains supplementary material, which is available to authorized users.

Background: Epidemiologic literature suggests that exposure to air pollutants is associated with fetal development. Objectives: We investigated maternal exposures to air pollutants during weeks 2–8 of pregnancy and their associations with congenital heart defects. Methods: Mothers from the National Birth Defects Prevention Study, a nine-state case–control study, were assigned 1-week and 7-week averages of daily maximum concentrations of carbon monoxide, nitrogen dioxide, ozone, and sulfur dioxide and 24-hr measurements of fine and coarse particulate matter using the closest air monitor within 50 km to their residence during early pregnancy. Depending on the pollutant, a maximum of 4,632 live-birth controls and 3,328 live-birth, fetal-death, or electively terminated cases had exposure data. Hierarchical regression models, adjusted for maternal demographics and tobacco and alcohol use, were constructed. Principal component analysis was used to assess these relationships in a multipollutant context. Results: Positive associations were observed between exposure to nitrogen dioxide and coarctation of the aorta and pulmonary valve stenosis. Exposure to fine particulate matter was positively associated with hypoplastic left heart syndrome but inversely associated with atrial septal defects. Examining individual exposure-weeks suggested associations between pollutants and defects that were not observed using the 7-week average. Associations between left ventricular outflow tract obstructions and nitrogen dioxide and between hypoplastic left heart syndrome and particulate matter were supported by findings from the multipollutant analyses, although estimates were attenuated at the highest exposure levels. Conclusions: Using daily maximum pollutant levels and exploring individual exposure-weeks revealed some positive associations between certain pollutants and defects and suggested potential windows of susceptibility during pregnancy. Citation: Stingone JA, Luben TJ, Daniels JL, Fuentes M, Richardson DB, Aylsworth AS, Herring AH, Anderka M, Botto L, Correa A, Gilboa SM, Langlois PH, Mosley B, Shaw GM, Siffel C, Olshan AF, National Birth Defects Prevention Study. 2014. Maternal exposure to criteria air pollutants and congenital heart defects in offspring: results from the National Birth Defects Prevention Study. Environ Health Perspect 122:863–872; http://dx.doi.org/10.1289/ehp.1307289

BACKGROUND Children with birth defects may face significant geographic barriers accessing medical care and specialized services. Using a Geographic Information Systems–based approach, one-way travel time and distance to access medical care for children born with spina bifida was estimated. METHODS Using 2007 road information from the Florida Department of Transportation, we built a topological network of Florida roads. Live-born Florida infants with spina bifida during 1998 to 2007 were identified by the Florida Birth Defects Registry and linked to hospital discharge records. Maternal residence at delivery and hospitalization locations were identified during the first year of life. RESULTS Of 668 infants with spina bifida, 8.1% (n = 54) could not be linked to inpatient data, resulting in 614 infants. Of those 614 infants, 99.7% (n = 612) of the maternal residential addresses at delivery were successfully geocoded. Infants with spina bifida living in rural areas in Florida experienced travel times almost twice as high compared with those living in urban areas. When aggregated at county levels, one-way network travel times exhibited statistically significant spatial autocorrelation, indicating that families living in some clusters of counties experienced substantially greater travel times compared with families living in other areas of Florida. CONCLUSION This analysis demonstrates the usefulness of linking birth defects registry and hospital discharge data to examine geographic differences in access to medical care. Geographic Information Systems methods are important in evaluating accessibility and geographic barriers to care and could be used among children with special health care needs, including children with birth defects. Birth Defects Research (Part A) 97:673–684, 2013. © 2013 Wiley Periodicals, Inc.

We assessed sociodemographic and clinical factors that are associated with survival among infants with congenital diaphragmatic hernia (CDH).Using data from the Metropolitan Atlanta Congenital Defects Program, we ascertained 150 infants born with CDH between 1979 and 2003 and followed via linkage with state vital records and the National Death Index. Kaplan-Meier survival probabilities and adjusted hazard ratios (HRs) were calculated for socioeconomic and clinical characteristics.Survival increased from 40 to 62% over the study period. White infants born before 1988 were 2.9 times less likely to survive than those born after 1988. Black infants' survival did not show significant improvement after 1988. White infants' survival was not significantly affected by poverty, whereas black infants born in higher levels of poverty were 2.7 times less likely to survive than black infants born in lower levels of neighborhood poverty. White infants with multiple major birth defects were 2.6 times less likely to survive than those with CDH alone. The presence of multiple defects was not significantly associated with survival among black infants.Survival among infants and children with CDH has improved over time among whites, but not among blacks. Poverty is associated with lower survival among blacks, but not among whites. The presence of multiple defects is associated with lower survival among whites, but not among blacks. The differential effects of poverty and race should be taken into account when studying disparities in health outcomes. Birth Defects Research 109:816-823, 2017. © 2017 Wiley Periodicals, Inc.

BACKGROUND: The prevalence of esophageal atresia (EA) has been shown to vary across different geographical settings. Investigation of geographical differences may provide an insight into the underlying etiology of EA. METHODS: The study population comprised infants diagnosed with EA during 1998 to 2007 from 18 of the 46 birth defects surveillance programs, members of the International Clearinghouse for Birth Defects Surveillance and Research. Total prevalence per 10,000 births for EA was defined as the total number of cases in live births, stillbirths, and elective termination of pregnancy for fetal anomaly (ETOPFA) divided by the total number of all births in the population. RESULTS: Among the participating programs, a total of 2943 cases of EA were diagnosed with an average prevalence of 2.44 (95% confidence interval [CI], 2.352.53) per 10,000 births, ranging between 1.77 and 3.68 per 10,000 births. Of all infants diagnosed with EA, 2761 (93.8%) were live births, 82 (2.8%) stillbirths, 89 (3.0%) ETOPFA, and 11 (0.4%) had unknown outcomes. The majority of cases (2020, 68.6%), had a reported EA with fistula, 749 (25.5%) were without fistula, and 174 (5.9%) were registered with an unspecified code. CONCLUSIONS: On average, EA affected 1 in 4099 births (95% CI, 1 in 39544251 births) with prevalence varying across different geographical settings, but relatively consistent over time and comparable between surveillance programs. Findings suggest that differences in the prevalence observed among programs are likely to be attributable to variability in population ethnic compositions or issues in reporting or registration procedures of EA, rather than a real risk occurrence difference. Birth Defects Research (Part A), 2012. (c) 2012 Wiley Periodicals, Inc.

Bladder exstrophy (BE) is a complex congenital anomaly characterized by a defect in the closure of the lower abdominal wall and bladder. We aimed to provide an overview of the literature and conduct an epidemiologic study to describe the prevalence, and maternal and case characteristics of BE. We used data from 22 participating member programs of the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR). All cases were reviewed and classified as isolated, syndrome, and multiple congenital anomalies. We estimated the total prevalence of BE and calculated the frequency and odds ratios for various maternal and case characteristics. A total of 546 cases with BE were identified among 26,355,094 births. The total prevalence of BE was 2.07 per 100,000 births (95% CI: 1.90-2.25) and varied between 0.52 and 4.63 among surveillance programs participating in the study. BE was nearly twice as common among male as among female cases. The proportion of isolated cases was 71%. Prevalence appeared to increase with increasing categories of maternal age, particularly among isolated cases. The total prevalence of BE showed some variations by geographical region, which is most likely attributable to differences in registration of cases. The higher total prevalence among male cases and older mothers, especially among isolated cases, warrants further attention. (C) 2011 Wiley Periodicals, Inc.

Conjoined twins (CT) are a very rare developmental accident of uncertain etiology. Prevalence has been previously estimated to be 1 in 50,000 to 1 in 100,000 births. The process by which monozygotic twins do not fully separate but form CT is not well understood. The purpose of the present study was to analyze diverse epidemiological aspects of CT, including the different variables listed in the Introduction Section of this issue of the Journal. The study was made possible using the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR) structure. This multicenter worldwide research includes the largest sample of CT ever studied. A total of 383 carefully reviewed sets of CT obtained from 26,138,837 births reported by 21 Clearinghouse Surveillance Programs (SP) were included in the analysis. Total prevalence was 1.47 per 100,000 births (95% CI: 1.32-1.62). Salient findings including an evident variation in prevalence among SPs: a marked variation in the type of pregnancy outcome, a similarity in the proportion of CT types among programs: a significant female predominance in CT: particularly of the thoracopagus type and a significant male predominance in parapagus and parasitic types: significant differences in prevalence by ethnicity and an apparent increasing prevalence trend in South American countries. No genetic, environmental or demographic significant associated factors were identified. Further work in epidemiology and molecular research is necessary to understand the etiology and pathogenesis involved in the development of this fascinating phenomenon of nature. (C) 2011 Wiley Periodicals, Inc.

Epidemiologic data on phocomelia are scarce. This study presents an epidemiologic analysis of the largest series of phocomelia cases known to date. Data were provided by 19 birth defect surveillance programs, all members of the International Clearinghouse for Birth Defects Surveillance and Research. Depending on the program, data corresponded to a period from 1968 through 2006. A total of 22,740,933 live births, stillbirths and, for some programs, elective terminations of pregnancy for fetal anomaly (ETOPFA) were monitored. After a detailed review of clinical data, only true phocomelia cases were included. Descriptive data are presented and additional analyses compared isolated cases with those with multiple congenital anomalies (MCA), excluding syndromes. We also briefly compared congenital anomalies associated with nonsyndromic phocomelia with those presented with amelia, another rare severe congenital limb defect. A total of 141 phocomelia cases registered gave an overall total prevalence of 0.62 per 100,000 births (95% confidence interval: 0.52–0.73). Three programs (Australia Victoria, South America ECLAMC, Italy North East) had significantly different prevalence estimates. Most cases (53.2%) had isolated phocomelia, while 9.9% had syndromes. Most nonsyndromic cases were monomelic (55.9%), with an excess of left (64.9%) and upper limb (64.9%) involvement. Most nonsyndromic cases (66.9%) were live births; most isolated cases (57.9%) weighed more than 2,499 g; most MCA (60.7%) weighed less than 2,500 g, and were more likely stillbirths (30.8%) or ETOPFA (15.4%) than isolated cases. The most common associated defects were musculoskeletal, cardiac, and intestinal. Epidemiological differences between phocomelia and amelia highlighted possible differences in their causes.

This study describes the epidemiology of congenital amelia (absence of limb/s), using the largest series of cases known to date. Data were gathered by 20 surveillance programs on congenital anomalies, all International Clearinghouse for Birth Defects Surveillance and Research members, from all continents but Africa, from 1968 to 2006, depending on the program. Reported clinical information on cases was thoroughly reviewed to identify those strictly meeting the definition of amelia. Those with amniotic bands or limb-body wall complex were excluded. The primary epidemiological analyses focused on isolated cases and those with multiple congenital anomalies (MCA). A total of 326 amelia cases were ascertained among 23,110,591 live births, stillbirths and (for some programs) elective terminations of pregnancy for fetal anomalies. The overall total prevalence was 1.41 per 100,000 (95% confidence interval: 1.26-1.57). Only China Beijing and Mexico RYVEMCE had total prevalences, which were significantly higher than this overall total prevalence. Some under-registration could influence the total prevalence in some programs. Liveborn cases represented 54.6% of total. Among monomelic cases (representing 65.2% of nonsyndromic amelia cases), both sides were equally involved, and the upper limbs (53.9%) were slightly more frequently affected. One of the most interesting findings was a higher prevalence of amelia among offspring of mothers younger than 20 years. Sixty-nine percent of the cases had MCA or syndromes. The most frequent defects associated with amelia were other types of musculoskeletal defects, intestinal, some renal and genital defects, oral clefts, defects of cardiac septa, and anencephaly. (C) 2011 Wiley Periodicals, Inc.

Although maternal age has been associated with a number of birth defects in several reports, the literature on the association of maternal age with isolated congenital heart defect (CHD) phenotypes has been limited. We evaluated CHD prevalence based on a cohort of 5,289 infants and fetuses with isolated CHDs born during the period 1968-2005 and ascertained by the Metropolitan Atlanta Congenital Defects Program (MACDP) among residents of five central counties in Atlanta. For our denominator, we obtained information on births to residents of the same counties from vital records (n = 1,301,143). We calculated prevalence ratios for 23 CHD phenotypes by several maternal age categories, using the group 25-29 years of age as a reference group. We used Poisson regression models to estimate adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs), controlling for maternal race, infant sex, and birth cohort. A maternal age of 35 years or older was associated with an increased prevalence for several CHD phenotypes: laterality defects (aPR = 2.06; CI 1.22-3.48), all conotruncal defects (aPR = 1.30; CI 1.03-1.65), and specifically for dextro-transposition of the great arteries (aPR = 1.65; CI 1.10-2.48), coarctation of the aorta (aPR = 1.54; CI 1.10-2.16), ventricular septal defects (aPR = 1.20; CI 1.06-1.36), and atrial septal defects (aPR = 1.36; CI 1.05-1.77). Our findings suggest that the birth prevalence of specific isolated CHDs varies with maternal age. Further studies are warranted to corroborate these observations, taking into account potential confounding by known modifiable risk factors.

OBJECTIVE:The goal was to estimate the number of children and adolescents, 0 to 19 years of age, living with spina bifida (SB) in the United States.METHODS:A retrospective study was conducted by using population-based, birth defect surveillance data from 10 US regions, with vital status ascertainment. Birth defect surveillance data were obtained from Arkansas, Georgia (5 central counties of metropolitan Atlanta), California (11 counties), Colorado, Iowa, New York (New York City excluded), North Carolina, Oklahoma, Texas, and Utah. We estimated the numbers of children 0 to 19 years of age who were living with SB in the 10 US regions in 2002, according to age group, race/ethnicity, and gender, and examined a long-term trend in the prevalence of SB among children 0 to 11 years of age in 1991–2002.RESULTS:The overall prevalence of SB among children and adolescents 0 to 19 years of age in the study regions was 3.1 cases per 10000 in 2002. The prevalence of SB among children was lower among male and non-Hispanic black children.CONCLUSIONS:The prevalence estimates of SB among children and adolescents varied according to region, race/ethnicity, and gender, which suggests possible variations in prevalence at birth and/or inequities in survival rates. Additional studies are warranted to elucidate the reasons for these variations and to derive prevalence estimates of SB among adults.

OBJECTIVE: We aimed to estimate the prevalence of Down syndrome (DS) among children and adolescents aged 0 to 19 years in 10 regions of the United States. METHODS: This study was a cross-sectional analysis of live-born infants with DS during 1979–2003 from 10 population-based birth defects registries in the United States. We estimated the prevalence of DS at birth and among children aged 0 to 19 years in each region and in all regions pooled. The prevalence of DS among children and adolescents was calculated overall and according to age group, race/ethnicity, infant gender, and presence of a major heart defect. RESULTS: From 1979 through 2003, the prevalence of DS at birth increased by 31.1%, from 9.0 to 11.8 per 10000 live births in 10 US regions. In 2002, the prevalence among children and adolescents (0–19 years old) was 10.3 per 10000. The prevalence of DS among children in a given age group consistently increased over time but decreased with age within a given birth cohort. The pooled prevalence of DS among children and adolescents was lower among non-Hispanic black individuals and other racial/ethnic groups compared with non-Hispanic white individuals; it was also lower among females than males. CONCLUSIONS: This study provides prevalence estimates of DS among children and adolescents from 10 US regions. These estimates varied according to region, race/ethnicity, and gender, suggesting possible variation in prevalence at birth or in survival rates on the basis of these characteristics.

Information on patterns and correlates of residential mobility can be important in studies of environmental factors and birth outcomes. The objective of this study was to describe residential mobility patterns and possible sociodemographic correlates of residential mobility among pregnant women. We obtained information on 656 mothers of infants with birth defects (cases) and 335 mothers of infants without birth defects (controls) from the geocoded dataset of the Birth Defects Risk Factor Surveillance Study, a case-control study conducted in Atlanta, Georgia, from 1993 through 1997. Using geographic information techniques, we measured distances mothers moved between residential addresses, and evaluated the proportion of moves and movement patterns by trimester. We used multivariate logistic regression to evaluate possible correlates of residential mobility for case and control mothers, including race, age, education, occupation, socioeconomic status, smoking, parity, and pregnancy planning. About 22% of women moved during pregnancy and most of them moved during the second trimester (11.9%), with no variation by case-control status. Among mothers who moved 51% moved within the same county. Pregnant women were more likely to move if they were younger (20-24 years, adjusted odds ratio (aOR) 3.39, 95% confidence interval (CI) 2.12-5.42;or = 30 years: reference), did not plan their pregnancy (aOR 1.66, 95% CI 1.18-2.34), and smoked (aOR 1.46, 95% CI 1.01-2.12). For these associations with mother's residential mobility, there were no appreciable confounding or effect modification effects by case-control status. In studies of pregnancy outcomes and potential environmental exposures based on residence at the time of delivery, residential mobility during pregnancy may not vary by case-control status, but it still needs to be considered as a possible source of exposure misclassification. Accounting for potential case-control differences in correlates of residential mobility could be useful in minimizing potential non-differential misclassification.

Associations between ambient air pollution levels during weeks 3-7 of pregnancy and risks of cardiovascular malformations were investigated among the cohort of pregnancies reaching at least 20 weeks' gestation that were conceived during January 1, 1986-March 12, 2003, in Atlanta, Georgia. Surveillance records obtained from the Metropolitan Atlanta Congenital Defects Program, which conducts active, population-based surveillance on this cohort, were reviewed to classify cardiovascular malformations. Ambient 8-hour maximum ozone and 24-hour average carbon monoxide, nitrogen dioxide, particulate matter with an average aerodynamic diameter of

Our objective was to evaluate the frequency and type of malformations associated with gastroschisis in Large 11001 of international data, to identify malformation patterns, and to evaluate the role of maternal age in non-isolated cases. Case-by-case information from 24 registries, all members of the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR), WERE evaluated. After the exclusion of other abdominal wall defects cases were classified as: (a) isolated: (h) recognizable syndrome, chromosomal or not; (c) multiple congenital anomalies (MCA). Our results showed that out of 3,322 total cases 469 non-isolated cases were registered (14.1%): 41 chromosomal syndromes. 24 other syndromes, and 404 MCA. Among MCA four groups of anomalies were most frequent: CNS (4.5%), cardiovascular (2.5%), limb (2.2%), and kidney anomalies (1.9%). No similar patterns emerged except two patterns resembling limb-body wall complex and OEIS. In both of them the gastroschisis could he however misclassified. Chromosomal trisomies and possibly non-syndromic MCA are associated, with,in older Maternal age more than isolated cases. On consideration of our Data and the most valid studies published in the literature, the best estimate of the proportion of gastroschisis associated with major unrelated defects is about 10%, with a few cases associated to recognizable syndromes. Recognized syndromes with gastroschisis seem to be so exceptional that the well documented and validated cases are worth being published as interesting case report. An appropriate case definition in etiological studies should include only isolated gastroschisis after an appropriate definition of isolated and non-isolted cases and a thorough case-by-case review. (c) 2007 Wiley-Liss, Inc.

BACKGROUND: One of the challenges in epidemiologic studies of congenital heart defects (CHDs) has been the lack of a current, standard nomenclature and classification system. Recently such a standard nomenclature became available from the Society of Thoracic Surgeons (STS) Congenital Heart Surgery Database. This study reports the classification of cases of CHDs in a birth defects surveillance database using modified STS nomenclature. METHODS: Records of infants and fetuses in the Metropolitan Atlanta Congenital Defects Program delivered during 1968–2003 with CHD diagnoses were reviewed by a team of pediatric cardiologists. The cases were assigned one or more STS codes and subsequently grouped into successively broader levels of aggregation. Aggregation was based on presumed morphogenetically similar developmental mechanisms. RESULTS: There were 12,639 cases reviewed, of which 89% had a single, primary STS code. Structural CHDs were found in 7,749 infants, while 4,890 were considered to have structurally normal hearts. Application of clinical CHD nomenclature improved the clinical accuracy of surveillance data by eliminating normal physiologic variants and obligatory shunt lesions. Classification also aggregated specific CHDs into groups appropriate for research and surveillance. CONCLUSIONS: Application of a current, standard CHD nomenclature and classification system to cases in a birth defects surveillance database improves the specificity of cardiac diagnoses and allows for the development of a flexible case aggregation system for monitoring of CHD prevalence. Birth Defects Research (Part A) 79:743–753, 2007. © 2007 Wiley-Liss, Inc.

OBJECTIVE: To examine the survival of infants with hypoplastic left heart syndrome (HLHS) and potential influence of demographic and clinical characteristics on survival using population-based data. METHODS: Infants with nonsyndromic HLHS (n = 212) born between 1979 and 2005 were identified through the Metropolitan Atlanta Congenital Defects Program. Vital status was ascertained through 2009 based on linkage with vital records. We estimated Kaplan-Meier survival probabilities stratified by select demographic and clinical characteristics. RESULTS: The overall survival probability to 2009 was 24% and significantly improved over time: from 0% in 1979–1984 to 42% in 1999–2005. Survival probability was 66% during the first week, 27% during the first year of life, and 24% during the first 10 years. Survival of very low and low birth weight or preterm infants and those born in high-poverty neighborhoods was significantly poorer. For children with information on surgical intervention (n = 88), the overall survival was 52%, and preterm infants had significantly poorer survival (31%) compared with term infants (56%). For children who survived to 1 year of age, long-term survival was ∼90%. CONCLUSIONS: Survival to adolescence of children with nonsyndromic HLHS born in metropolitan Atlanta has significantly improved in recent years, with those born full term, with normal birth weight, or in a low-poverty neighborhood having a higher survival probability. Survival beyond infancy to adolescence is high. A better understanding of the growing population of survivors with HLHS is needed to inform resource planning.

BACKGROUND The impact of prenatal diagnosis on the live birth prevalence of Down syndrome (trisomy 21) has been described. This study examines the prevalence of Down syndrome before (1990–1993) and after inclusion of prenatally diagnosed cases (1994–1999) in a population-based registry of birth defects in metropolitan Atlanta. METHODS We identified infants and spontaneous fetal deaths with Down syndrome (n = 387), and pregnancies electively terminated after a prenatal diagnosis of Down syndrome (n = 139) from 1990 to 1999 among residents of metropolitan Atlanta from a population-based registry of birth defects, the Metropolitan Atlanta Congenital Defects Program (MACDP). Only diagnoses of full trisomy 21 were included. Denominator information on live births was derived from State of Georgia birth certificate data. We compared the prevalence of Down syndrome by calendar period (1990–1993, 1994–1999), maternal age (

BACKGROUND: The Metropolitan Atlanta Congenital Defects Program (MACDP) is a population-based birth defects surveillance program administered by the Centers for Disease Control and Prevention (CDC) that has been collecting, analyzing, and interpreting birth defects surveillance data since 1967. This paper presents an overview of MACDP current methods and accomplishments over the past 35 years. METHODS: MACDP actively monitors major birth defects among infants born to residents of five counties of metropolitan Atlanta, an area with approximately 50,000 annual births. Cases are ascertained from multiple sources, coded using a modified British Pediatric Association six-digit code, and reviewed and classified by clinical geneticists. RESULTS: MACDP has monitored trends in birth defects rates and has served as a case registry for descriptive, risk factor, and prognostic studies of birth defects, including studies of Agent Orange exposure among Vietnam War veterans, maternal use of multivitamins, diabetes, febrile illnesses, and survival of children with neural tube defects. MACDP has served as a data source for one of the centers participating in the National Birth Defects Prevention Study, and for developing and evaluating neural tube defects prevention strategies related to the periconceptional use of folic acid supplements. CONCLUSIONS: Since its inception, MACDP has served as a resource for the development of uniform methods and approaches to birth defect surveillance across the United States and in many other countries, monitoring birth defects rates, and as a case registry for various descriptive, etiologic, and survival studies of birth defects. MACDP has also served as a training ground for a large number of professionals active in birth defects epidemiology. Birth Defects Research (Part A) 67:617– 624, 2003. Published 2003 Wiley-Liss, Inc. †

This study aimed to evaluate the survival of a cohort of liveborn infants diagnosed with encephalocele during a 20-year period and the variation of such survival by selected demographic and clinical characteristics. We reviewed data from the Metropolitan Atlanta Congenital Defects Program (MACDP) to ascertain all live births diagnosed with encephalocele (n = 83) from 1979 to 1998. Of these, 66 (79%) had isolated defects. Among 70 liveborn infants with site of the defect specified, 50 were classified as having posterior and 20 with anterior defects. To identify their vital status, we used data from MACDP hospital records and vital records from the State of Georgia supplemented by linking registry data with the National Death Index from 1979 to 1999. Among children with encephalocele, 76.0% of the deaths (19/25) occurred during the first day of life. The survival probability to 1 year of age was 70.8%[95% confidence intervals (CI) 60.9, 80.7] and to 20 years of age was 67.3%[95% CI 55.7, 78.8]. In multivariable analysis, factors associated with increased mortality were low birthweight (

Background The Hungarian Case-Control Surveillance of Congenital Abnormalities was established in 1980. This article describes how the Hungarian Case-Control Surveillance of Congenital Abnormalities was first organized and is currently maintained. The baseline statistics are provided and potential venues of postmarketing surveillance of drug teratogenicity and other public health tasks and research are proposed. Methods Cases with congenital abnormalities and patient controls with Down syndrome were selected from the Hungarian Congenital Abnormality Registry. Population controls without congenital abnormalities were selected from the National Birth Registry on the basis of three matching criteria: sex, week of birth, and district of parent's residence. Three sources of information concerning drug exposures, maternal disorders, and pregnancy complications, among others, were used: (1) prospective and medically recorded data from antenatal care logbooks and discharge summaries; (2) retrospective maternal self-reported data obtained with a structured questionnaire in all the three study groups; and (3) data collected by regional nurse in house visits to nonrespondent cases and patient controls. Twenty-five congenital abnormality groups were evaluated. During the 17-year period of data collection, 22,843 cases, 38,151 population controls, and 834 patient controls were incorporated into the data set, constituting the largest population-based case-control data set of congenital abnormalities to date. Results Demographic features of pregnant women and informative offspring are presented along with the distribution of 25 main groups of congenital abnormalities. Conclusions This system is appropriate for postmarketing the surveillance of drug teratogenicity, for the improvement of congenital abnormality diagnosis, to get informed consent, to have a communication with parents and to provide material for research. Teratology 63:176–185, 2001. © 2001 Wiley-Liss, Inc.

As the evidence for an association between spina bifida and parental agricultural occupations is inconclusive, we evaluated this association and the potential associations between spina bifida and other parental occupations. Three register-based case-referent studies were conducted in Sweden, Spain, and Hungary. From the registries of congenital malformations in each country, 482, 478, and 1119 cases with spina bifida were identified, respectively. Concluding, the results are not totally consistent but point to an increased risk of spina bifida among women in agricultural occupations.

This retrospective cohort study was planned to determine whether recommendations to take folic acid have in fact lessened the risk of neural tube defects. Recommendations typically include eating a healthy diet and takingfolic acid supplements when planning pregnancy or throughout the childbearing years. In a few countries, including the United States, flour is fortified so that much of the population will receive at least a small supplemental amount of folic acid. Many governments promote the use of supplements because folic acid is inexpensive, safe, and easy to use. The authors acquired information on more than 13 million births from 13 birth defects registries in Norway that monitored rates of neural tube defects from 1988 to 1998. Cases of anencephaly and spina bifida totaled 8636. Rates of defects were stable during the 10-year monitoring interval in most areas. There were no evident changes in rates of defects after local recommendations were issued. Comparable findings were obtained when analyzing anencephaly and spina bifida separately and combined. Folic acid use in Europe is, in general, low; in Norway, it is approximately 10%. In China, intensive educational efforts and a high rate of planned pregnancies probably are responsible for the effectiveness of a public health campaign to promote the use of folic acid supplements. Rates of folic acid use generally follow economic and educational trends. Fortifying flour with folic acid holds promise for delivering some folic acid to a large part of the population, crossing social and economic barriers. Blood folate levels have increased rapidly where this practice is followed. It is estimated that thousands of neural tube defects occurring since 1992 could have been prevented.

OBJECTIVE: This study examined changes in survival among children with Down syndrome (DS) by race/ethnicity in 10 regions of the United States. A retrospective cohort study was conducted on 16 506 infants with DS delivered during 1983–2003 and identified by 10 US birth defects monitoring programs. Kaplan-Meier survival probabilities were estimated by select demographic and clinical characteristics. Adjusted hazard ratios (aHR) were estimated for maternal and infant characteristics by using Cox proportional hazard models. RESULTS: The overall 1-month and 1-, 5-, and 20-year survival probabilities were 98%, 93%, 91%, and 88%, respectively. Over the study period, neonatal survival did not improve appreciably, but survival at all other ages improved modestly. Infants of very low birth weight had 24 times the risk of dying in the neonatal period compared with infants of normal birth weight (aHR 23.8; 95% confidence interval [CI] 18.4–30.7). Presence of a heart defect increased the risk of death in the postneonatal period nearly fivefold (aHR 4.6; 95% CI 3.9–5.4) and continued to be one of the most significant predictors of mortality through to age 20. The postneonatal aHR among non-Hispanic blacks was 1.4 (95% CI 1.2–1.8) compared with non-Hispanic whites and remained elevated by age 10 (2.0; 95% CI 1.0–4.0). CONCLUSIONS: The survival of children born with DS has improved and racial disparities in infant survival have narrowed. However, compared with non-Hispanic white children, non-Hispanic black children have lower survival beyond infancy. Congenital heart defects are a significant risk factor for mortality through age twenty.

Background: Population-based empirical information to inform health care professionals working with children with spina bifida currently is lacking. Spina bifida is a highly complex condition that not only affects mobility but many additional aspects of life. We have developed a pilot project that focuses on a broad range of domains: surgeries, development and learning, nutrition and physical growth, mobility and functioning, general health, and family demographics. Specifically, we will: (1) explore the feasibility of identifying and recruiting participants using different recruitment sources, (2) test a multidisciplinary module to collect the data, (3) determine the utility of different methods of retrieving the data, and (4) summarize descriptive information on living with spina bifida. Objective: The overall objective of the project was to provide information for a future multistate prospective study on the natural history of spina bifida. Methods: Families with a child 3 to 6 years of age with a diagnosis of spina bifida were eligible for enrollment. Eligible families were identified through a US population-based tracking system for birth defects and from a local spina bifida clinic. Results: This is an ongoing project with first results expected in 2013. Conclusions: This project, and the planned multistate follow-up project, will provide information both to health care professionals experienced in providing care to patients with spina bifida, and to those who have yet to work with this population. The long-term purpose of this project is to increase the knowledge about growing up with spina bifida and to guide health care practices by prospectively studying a cohort of children born with this condition. (JMIR Res Protoc 2013; 2(1): e2) doi:10.2196/resprot.2209

Cloacal exstrophy presents as a complex abdominal wall defect thought to result from a mesodermal abnormality. Anatomically, its main components are Omphalocele, bladder Exstrophy and Imperforate anus. Other associated malformations include renal malformations and Spine defects (OEIS complex). Historically, the prevalence ranges from 1 in 200,000 to 400,000 births, with higher rates in females. Cloacal exstrophy is likely etiologically heterogeneous as suggested by its recurrence in families and occurrence in monozygotic twins. The defect has been described in infants with limb-body wall, with trisomy 18, and in one pregnancy exposed to Dilantin and diazepam. Due to its rarity, the use of a nonspecific diagnostic code for case identification, and lack of validation of the clinical findings, cloacal exstrophy remains an epidemiologic challenge. The purpose of this study was to describe the prevalence, associated anomalies and maternal characteristics among infants born with cloacal exstrophy. We used data from the International Clearinghouse for Birth Defects Surveillance and Research submitted from 18 birth defect surveillance programs representing 24 countries. Cases were clinically evaluated locally and reviewed centrally by two authors. Cases of persistent cloaca were excluded. A total of 186 cases of cloacal exstrophy were identified. Overall prevalence was 1 in 131,579 births: ranging from 1 in 44,444 births in Wales to 1 in 269,464 births in South America. Live birth prevalence was 1 in 184,195 births. Prevalence ratios did not vary by maternal age. Forty-two (22.6%) cases met the criteria for the OEIS complex, whereas 60 (32.3%) were classified as OEI and 18 (9.7%) as EIS (one with suspected VATER (0.5%)). Other findings included two cases with trisomy 13 (one without a karyotype confirmation), one with mosaic trisomy 12 (0.5%), one with mosaic 45, X (0.5%) and one classified as having amnion band sequence (0.5%). Twenty-seven (14.5%) infants had other anomalies unrelated to cloacal exstrophy. Cloacal exstrophy is a rare anomaly with variability in prevalence by geographic location. The proportion of cases classified as OEIS complex was lower in this study than previously reported. Among all cases, 54.8% were reported to have an omphalocele. (C) 2011 Wiley Periodicals, Inc.