An overview of infant mortality and birth defects in the United States

US Mortality Attributable to Congenital Heart Disease Across the Lifespan From 1999 Through 2017 Exposes Persistent Racial/Ethnic Disparities

BACKGROUND

Congenital heart disease (CHD) accounts for ≈40% of deaths in US children with birth defects. Previous US data from 1999 to 2006 demonstrated an overall decrease in CHD mortality. Our study aimed to assess current trends in US mortality related to CHD from infancy to adulthood over the past 19 years and determine differences by sex and race/ethnicity.

METHODS

We conducted an analysis of death certificates from 1999 to 2017 to calculate annual CHD mortality by age at death, race/ethnicity, and sex. Population estimates used as denominators in mortality rate calculations for infants were based on National Center for Health Statistics live birth data. Mortality rates in individuals ≥1 year of age used US Census Bureau bridged-race population estimates as denominators. We used joinpoint regression to characterize temporal trends in all-cause mortality, mortality resulting directly attributable to and related to CHD by age, race/ethnicity, and sex.

RESULTS

There were 47.7 million deaths with 1 in 814 deaths attributable to CHD (n=58 599). Although all-cause mortality decreased 16.4% across all ages, mortality resulting from CHD declined 39.4% overall. The mean annual decrease in CHD mortality was 2.6%, with the largest decrease for those >65 years of age. The age-adjusted mortality rate decreased from 1.37 to 0.83 per 100 000. Males had higher mortality attributable to CHD than females throughout the study, although both sexes declined at a similar rate (≈40% overall), with a 3% to 4% annual decrease between 1999 and 2009, followed by a slower annual decrease of 1.4% through 2017. Mortality resulting from CHD significantly declined among all races/ethnicities studied, although disparities in mortality persisted for non-Hispanic Blacks versus non-Hispanic Whites (mean annual decrease 2.3% versus 2.6%, respectively; age-adjusted mortality rate 1.67 to 1.05 versus 1.35 to 0.80 per 100 000, respectively).

CONCLUSIONS

Although overall US mortality attributable to CHD has decreased over the past 19 years, disparities in mortality persist for males in comparison with females and for non-Hispanic Blacks in comparison with non-Hispanic Whites. Determining factors that contribute to these disparities such as access to quality care, timely diagnosis, and maintenance of insurance will be important moving into the next decade.

The disproportionate cost of operation and congenital anomalies in infancy

BACKGROUND

Congenital anomalies are the leading cause of infant death and pediatric hospitalization, but existing estimates of the associated costs of health care are either cross-sectional surveys or economic projections. We sought to determine the percent of total hospital health care expenditures attributable to major anomalies requiring surgery within the first year of life.

METHODS

Utilizing comprehensive California statewide data from 2008 to 2012, cohorts of infants undergoing major surgery, with birth defects and with surgical anomalies, were constructed alongside a referent group of newborns with no anomalies or operations. Cost-to-charge and physician fee ratios were used to estimate hospital and professional costs, respectively. For each cohort, costs were broken down according to admission, birth episode, and first year of life, with additional stratifications by birth weight, gestational age, and organ system.

RESULTS

In total, 68,126 of 2,205,070 infants (3.1%) underwent major surgery (n = 32,614) or had a diagnosis of a severe congenital anomaly (n = 57,793). These accounted for $7.7 billion of the $18.9 billion (40.7%) of the total health care costs/expenditures of the first-year-of-life hospitalizations, $7.0 billion (48.6%) of the costs for infants with comparatively long birth episodes, and $5.2 billion (54.7%) of the total neonatal intensive care unit admission costs. Infants with surgical anomalies (n = 21,264) totaled $4.1 billion (21.7%) at $80,872 per infant. Cardiovascular and gastrointestinal diseases accounted for most admission costs secondary to major surgery or congenital anomalies.

CONCLUSION

In a population-based cohort of infant births compared with other critically ill neonates, surgical congenital anomalies are disproportionately costly within the United States health care system. The care of these infants, half of whom are covered by Medi-Cal or Medicaid, stands as a particular focus in an age of reform of health care payments.

Human Pluripotent Stem Cells to Assess Developmental Toxicity in the Osteogenic Lineage

Musculoskeletal birth defects are frequent, yet their causes remain insufficiently investigated. Aside from genetic factors, exposure to environmental toxicants is suspected to contribute to the etiology of skeletal malformations. However, most chemicals in the environment are insufficiently characterized for their potential to cause harm to the differentiation of osteoblasts, the bone-forming cells and thereby the development of the skeleton.This lack of information primarily stems from animal testing being prohibitively expensive and time-consuming, which has prompted the development of predictive in vitro alternative methods. With the advent of mouse embryonic stem cells, which represent cells with the potential to become any of the 200 cell types in the body, among them osteoblasts, the past 15 years have borne suitable opportunities to assess chemicals in vitro. However, with an increasing understanding of the differences between mouse and human embryonic development, a need for human-specific developmental toxicity testing has risen. This chapter provides a detailed protocol on how to differentiate human embryonic stem cells into the osteogenic lineage, how to assess differentiation inhibition and how to evaluate such findings in relation to the mitochondrial activity of human embryonic stem cells and human fibroblasts, while exposed to a potential toxicant. Together, these endpoints allow for a human-specific screening of developmental toxicity specifically related to the osteogenic lineage.

An overview of concepts and approaches used in estimating the burden of congenital disorders globally

Congenital disorders are an important cause of pregnancy loss, premature death and life-long disability. A range of interventions can greatly reduce their burden, but the absence of local epidemiological data on their prevalence and the impact of interventions impede policy and service development in many countries. In an attempt to overcome these deficiencies, we have developed a tool—The Modell Global Database of Congenital Disorders (MGDb) that combines general biological principles and available observational data with demographic data, to generate estimates of the birth prevalence and effects of interventions on mortality and disability due to congenital disorders. MGDb aims to support policy development by generating country, regional and global epidemiological estimates. Here we provide an overview of the concepts and methodological approach used to develop MGDb.

Survival Disparities Associated with Congenital Diaphragmatic Hernia

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.

The Ultrasonic Microsurgical Anatomical Comparative Study of the CHD Fetuses and Their Clinical Significance

The aim of our study was to increase the detection rate of fetal cardiac malformations for congenital heart disease (CHD). The ultrasonic and microanatomical methods were combined to study the CHD cases firstly, which could provide the microsurgical anatomical basis to the prenatal ultrasonic diagnosis which was used in suspected CHD and help the sonographer to improve the quality of fetal cardiac diagnosis. We established the ultrasonic standard section of the 175 complex CHD cases and collected the fetal echocardiography image files. The induced/aborted fetuses were fixed by 4% paraformaldehyde and dissected by the ultrasonic microsurgical anatomy. This research could obtain the fetal cardiac anatomic cross-sectional images which was consistent with the ultrasonic standard section and could clearly show the internal structure of the vascular malformation that optimized the ultrasound examination individually. This method could directly display the variation of the CHD fetal heart clearly and comprehensively help us to understand the complex fetal cardiac malformation from the internal structure of the vascular malformation which was consolidated by the anatomical basis of the fetal heart. This study could improve the integrity and accuracy of the prenatal cardiac ultrasound examination tremendously.

Age at referral and mortality from critical congenital heart disease

BACKGROUND AND OBJECTIVE

Newborn pulse oximetry screening is recommended to promote early referral of neonates with critical congenital heart disease (CCHD) and reduce mortality; however, the impact of late referral on mortality is not well defined. The purpose of this population-based study was to describe the association between timing of referral to a cardiac center and mortality in 2360 liveborn neonates with CCHD.

METHODS

Neonates with CCHD born before pulse oximetry screening (1996-2007) were selected from the Texas Birth Defects Registry and linked to state birth and death records. Age at referral was ascertained from date of first cardiac procedure at a cardiac center. Logistic and Cox proportional hazards regression models were used to estimate factors associated with late referral and mortality; the Kaplan-Meier method was used to estimate 3-month survival.

RESULTS

Median age at referral was 1 day (25th-75th percentile: 0-6 days). Overall, 27.5% (649 of 2360) were referred after age 4 days and 7.5% (178 of 2360) had no record of referral. Neonatal mortality was 18.1% (277 of 1533) for those referred at 0 to 4 days of age, 9.0% (34 of 379) for those referred at 5 to 27 days of age, and 38.8% (69 of 178) for those with no referral. No improvement in age at referral was found across the 2 eras within 1996-2007.

CONCLUSIONS

A significant proportion of neonates with CCHD experienced late or no referral to cardiac specialty centers, accounting for a significant number of the deaths. Future population-based studies are needed to determine the benefit of pulse oximetry screening on mortality and morbidity.

National trend in congenital heart disease mortality in China during 2003 to 2010: a population-based study

BACKGROUND

Previous studies suggest that mortality from congenital heart diseases (CHDs) is declining in the United States. But we do not know what the CHD mortality trend is in China, especially the rural versus urban patterns. Our study aimed to determine recent changes in death caused by CHD in China and describe CHD mortality in rural and urban Chinese populations.

METHODS

The data source was the China Ministry of Health 2003 to 2010 annual reports. Mortality was defined as death caused by CHD. Mortality rates for each year were calculated per 10,000,000 person-years. Poisson regression and descriptive analyses were conducted for overall trend and subgroup analysis was conducted by sex, age, and urban versus rural residency to understand potential disparities in mortality.

RESULTS

From 2003 to 2010, the overall mortality rate increased from 141 per 10,000,000 person-years in 2003 to 229 per 10,000,000 person-years in 2010, a 62.4% relative increase. This represents a region-sex adjusted annual increase of 9% (incidence rate ratio, 1.09; 95% confidence interval, 1.09-1.10). The increase in CHD mortality was not uniformly observed across age groups, urban versus rural residence, and sex. The relative increases were 65.3%, 212.2%, and 131.7% for ages 1 to 10 years, 21 to 64 years, and 65 years or older groups, respectively. Urban areas had a relative increase of 154.5% versus 5.3% for rural areas. Females who lived in an urban environment had a relative increase of 313.5%.

CONCLUSIONS

Our observation showed an obvious increasing trend of CHD mortality in China. What is more, the increase in CHD mortality was not uniformly observed across subgroups. Such information is needed for strategy-making procedures.

Mortality resulting from congenital heart disease among children and adults in the United States, 1999 to 2006

BACKGROUND

Previous reports suggest that mortality resulting from congenital heart disease (CHD) among infants and young children has been decreasing. There is little population-based information on CHD mortality trends and patterns among older children and adults.

METHODS AND RESULTS

We used data from death certificates filed in the United States from 1999 to 2006 to calculate annual CHD mortality by age at death, race-ethnicity, and sex. To calculate mortality rates for individuals ≥1 year of age, population counts from the US Census were used in the denominator; for infant mortality, live birth counts were used. From 1999 to 2006, there were 41,494 CHD-related deaths and 27,960 deaths resulting from CHD (age-standardized mortality rates, 1.78 and 1.20 per 100,000, respectively). During this period, mortality resulting from CHD declined 24.1% overall. Mortality resulting from CHD significantly declined among all race-ethnicities studied. However, disparities persisted; overall and among infants, mortality resulting from CHD was consistently higher among non-Hispanic blacks compared with non-Hispanic whites. Infant mortality accounted for 48.1% of all mortality resulting from CHD; among those who survived the first year of life, 76.1% of deaths occurred during adulthood (≥18 years of age).

CONCLUSIONS

CHD mortality continued to decline among both children and adults; however, differences between race-ethnicities persisted. A large proportion of CHD-related mortality occurred during infancy, although significant CHD mortality occurred during adulthood, indicating the need for adult CHD specialty management.

Congenital abnormalities and multiple sclerosis

Background

There is a strong maternal parent-of-origin effect in determining susceptibility to multiple sclerosis (MS). One hypothesis is that an abnormal intrauterine milieu leading to impaired fetal development could plausibly also result in increased susceptibility to MS. A possible marker for this intrauterine insult is the presence of a non-fatal congenital anomaly.

Methods

We investigated whether or not congenital anomalies are associated with MS in a population-based cohort. We identified 7063 MS index cases and 2655 spousal controls with congenital anomaly information from the Canadian Collaborative Project on Genetic Susceptibility to MS (CCPGSMS).

Results

The frequency of congential anomalies were compared between index cases and controls. No significant differences were found.

Conclusions

Congenital anomalies thus do not appear to be associated with MS. However, we did not have complete data on types and severity of congenital anomalies or on maternal birth history and thus this study should be regarded as preliminary.

Effect of different dosage and administration schedules of folic acid on blood folate levels in a population of Honduran women of reproductive age

Background

Observational studies and clinical trials have shown conclusive evidence that periconceptional folic acid supplementation prevents up to 70 % of neural tube defects (NTD). The Honduran government wanted to implement a supplementation programme of folic acid but needed to assess the relative effects of two dosages of folic acid.

Objective

To determine the effect of two dosages of folic acid on blood folate levels in Honduran female factory workers aged 18 to 49 years.

Design

This was a randomized, double-blind control supplementation trial conducted in Choloma, Honduras. A total of 140 eligible women were randomly assigned to two dosage groups and followed up for 12 weeks. One group received a daily dosage of 1 mg folic acid and the other a once weekly dosage of 5 mg. Serum folate and red blood cell folate levels were determined by radioassay at baseline, 6 weeks and 12 weeks.

Results

Serum folate levels increased from 6·3 (se 0·2) to 14·9 (se 0·6) ng/ml (P < 0·0001) in women assigned to the 1 mg/d group and from 6·9 (se 0·3) to 10·1 (se 0·4) ng/ml (P < 0·0001) in those assigned to the 5 mg/week group. Red blood cell folate concentrations also increased significantly in both groups, albeit more slowly. Educational level, age and BMI were not associated with the changes in serum and red blood cell folate levels during the supplementation period. However, a differential effect on serum folate levels by dosage group and time was observed.

Conclusions

Although both folate supplementation regimens increased serum and red blood cell folate levels significantly among the women studied, blood folate levels that are considered to be protective of NTD were reached faster with the daily dosage of 1 mg folic acid.

The effectiveness of Teratology Information Services (TIS)

BACKGROUND

Women and their health care providers have few reliable sources of information regarding the safety of exposures in pregnancy and lactation. Evidence-based information on these topics is provided by Teratology Information Services (TIS). Access to TIS, however, is limited in many regions, and many services have difficulty maintaining ongoing funding. The objective of this review is to highlight published reports of the effectiveness of TIS in improving maternal and neonatal health.

METHODS

A search of the Pub Med and Econ Lit databases was performed with no date restriction, using the search terms teratology, information, counseling, pregnancy, effectiveness, birth defects.

RESULTS

Information disseminated from TIS has been shown to prevent congenital malformations, unnecessary pregnancy terminations, and occupational risks. TIS support optimal nutritional supplementation in pregnancy and optimal drug therapy in pregnancy and breast-feeding. In addition, they correct misperceptions of risk and facilitate knowledge transfer and translation. TIS have the potential to provide health care cost savings.

CONCLUSIONS

TIS are vital services in supporting optimal maternal and neonatal health. A formal economic evaluation of TIS is required in order to inform resource allocation decision-making and continued funding of these services.

Determinants of survival in children with congenital abnormalities: a long-term population-based cohort study

BACKGROUND

Today more children with birth defects survive early childhood because of improved medical care; however, little information is available about patterns of long-term mortality and survival in this population. In particular, it is not clear whether other birth characteristics, apart from birth defects, have any role in their mortality.

METHODS

Two large cohorts of children with and without birth defects were followed for up to 17 years. More than 45,000 children with birth defects, and 45,000 matched children without birth defects born in Ontario between 1979 and 1986 were followed. Throughout the study period long-term survival rates and the risk of death were compared between the 2 cohorts. Birth characteristics were also examined to determine their effect on the risk of death.

RESULTS

During the study the deaths of 3620 and 301 children with and without birth defects, respectively, were recorded, indicating that those with birth defects had a 13 times higher rate of mortality (relative risk [RR], 12.9, 95% confidence interval [CI], 12.1-13.7). Mortality rates in the birth-defects cohort remained higher even after 10-15 years. In both groups children of low gestational age and low birth weight had a higher risk of death. There was a strong dose-response relationship between the number of defects and the risk of death.

CONCLUSIONS

Children born with abnormalities face many challenges throughout their lifetimes. If they survive the high mortality risk of the first year of life, they still have to face the considerably higher risk of death in the years to come. In addition to birth defects, other birth characteristics play an independent role in their mortality. These indicators could be used to identify high-risk children.

Ethnic differences in congenital malformations in the Netherlands: analyses of a 5-year birth cohort

Congenital malformations are among the major causes of perinatal mortality and morbidity at present. Research into the ethnic diversity of congenital malformations can form a basis both for aetiological studies and for health care advice and planning. This study compared the overall prevalence of congenital malformations, the prevalence in different organ systems and of several specific malformations between different maternal ethnic groups in the Netherlands using a 5-year national birth cohort (1996-2000) containing 881 800 births. Maternal ethnic groups considered were Dutch; Mediterranean (Moroccan/Turkish); other European; Black; Hindu and Asian. Mediterranean women had a 20% higher risk of having a child with a congenital malformation than Dutch women (age-adjusted OR = 1.21 [95% CI 1.16, 1.27]). They showed an increased risk of malformations in several organ systems such as the central nervous system and sensory organs, the urogenital system and skin and abdominal wall. Further, they had an increased risk of the group of chromosomal malformations/multiple malformations/syndromes. For the specific group of multiple malformations the maternal age adjusted OR was 1.80 [95% CI 1.47, 2.20]. The Black group showed a significantly increased risk of skeletal and muscular malformations (age adjusted OR = 1.76 [95% CI 1.53, 2.02]) with a sixfold increased risk of polydactyly compared with the Dutch group. For Mediterranean women, the largest and fastest growing group of immigrants in the Netherlands, this study demonstrated an increased risk of congenital malformations.

Contribution of malformations and genetic disorders to mortality in a children's hospital

Malformations and genetic disorders are the leading cause of infant mortality in the US. Many malformations have a genetic basis due to genic, chromosomal, or multifactorial causation. We have studied the proportion of pediatric cases in a university-affiliated children's hospital that died of malformations and genetic disorders. We reviewed, retrospectively, deaths over a 4 year period (1994-1998) at Primary Children's Medical Center (PCMC), a university-affiliated tertiary children's referral hospital in Utah. The age at death and the cause of death were recorded for each case. We analyzed 523 cases; 180 (34.4%) deaths were due to malformations and genetic disorders. Of those 180, 30 (16.7%) had chromosome anomalies, 21 (11.7%) had a recognizable malformation syndrome, 118 (65.6%) had a malformation of unknown cause, and 11 (6.1%) had some other genetic disorder. One hundred and twenty-two (23.3%) deaths were due to trauma (accidental and non-accidental). Seventy-nine (15.1%) deaths were due to short gestation or perinatal complications. Forty-five (8.6%) deaths were due to an infectious disease and 45 (8.6%) from neoplasms. Thirteen (2.5%) were diagnosed for sudden infant death "syndrome." Twelve (2.3%) patients with malformations and/or genetic disorders died of an acquired condition not clearly related to the underlying disorder. Seven (1.3%) patients died of an unknown cause and 20 (3.8%) patients died of other specified conditions. In addition, 51.0% patients (age <1 year) died of a malformation and/or genetic disorder. Genetic disorders and malformations are a substantial cause of mortality in a referral pediatric hospital. Knowledge of the impact of genetic diseases on mortality is important for the integration of preventive measures and health care strategies to care effectively for patients and their families. This information emphasizes the importance of further study of whether or not early recognition influences mortality rate and management.

Mortality throughout early childhood for Michigan children born with congenital anomalies, 1992-1998

BACKGROUND

Congenital anomalies are a leading cause of infant deaths, accounting for almost a fifth of all infant deaths. Few studies have researched the survival experience of infants born with congenital anomalies past the infant stage.

METHODS

Using birth and death files routinely linked to the Michigan Birth Defects Registry, we identified all singleton infants during calendar years 1992 through 1998 with reportable congenital anomalies for our study. A comparative file of children born without congenital anomalies during the same time period was developed using linked birth and death files. The mortality data were assessed by age at death (through age six) and race to determine mortality rates, relative risks, hazard ratios, and survival trends.

RESULTS

Throughout early childhood, children born with congenital anomalies had a high risk of mortality compared with all other children. The overall 7-year hazard ratio comparing children with congenital anomalies with all other children was 7.2. Overall mortality rates for black children were significantly higher than white children through the age of seven, irrespective of whether they had congenital anomalies. Among children with congenital anomalies, this disparity disappeared after adjusting for birth weight, sex, mother's age, mother's education, and number of organ systems affected.

CONCLUSIONS

Compared with children without congenital anomalies, children born with congenital anomalies had a higher risk of mortality well beyond the infant period. Racial disparities in mortality rates among children with congenital anomalies were due to confounding factors.

Patterns of first-year survival among infants with selected congenital anomalies in Texas, 1995-1997

BACKGROUND

Few registry-based studies have investigated survival among infants with congenital anomalies. We conducted a registry-based study to examine patterns and probability of survival during the first year of life among infants with selected congenital anomalies.

METHODS

Data from the Texas Birth Defects Monitoring Division were merged with linked birth-infant death files for 2,774 infants born January 1, 1995 to December 31, 1997, with at least 1 of 23 common anomalies. Deaths before the first birthday were assessed from infant death files. Kaplan-Meier was used to estimate first-year survival; first-year survival was assessed for specific anomalies and by the number of life-threatening anomalies.

RESULTS

Overall, 80.8% of infants with these 23 anomalies survived the first year of life. We observed the highest survival rates for infants with gastroschisis (92.9%, 95% CI = 86.8, 96.3), trisomy 21 (92.3%, 95% CI = 89.5, 94.4) or cleft lip with or without cleft palate (87.6%, 95% CI = 84.0, 90.5). Infants with intermediate survival rates included those with microcephaly (79.7%; 95% CI = 73.6, 84.6), tetralogy of Fallot (75.0%; 95% CI = 65.5, 82.2), or with diaphragmatic hernia (72.8%; 95% CI = 61.8, 81.2). As expected, all infants with anencephaly and almost all infants with trisomy 13 or trisomy 18 died during the first year of life. First-year survival declined as the number of co-occurring life-threatening anomalies increased.

CONCLUSIONS

Overall, first-year survival for infants with congenital anomalies was high. Additional population-based studies are needed to quantify improvements in first-year survival.

Major birth defects in very low birth weight infants in the Vermont Oxford Network

OBJECTIVE

To study the frequency and types of major birth defects in very low birth weight (VLBW) infants and their impact on mortality and resource use.

STUDY DESIGN

Analysis of data from the Vermont Oxford Network Database from 1994 and 1995 on infants with birth weights of 501 to 1500 g. Major birth defects were reported from a list of 40 defined major defects or if they were considered lethal or life-threatening. Mortality and length of stay were determined.

RESULTS

Major birth defects were present in 823 (4.3%) of 19,228 VLBW infants from 147 hospitals. The most common categories were chromosomal anomalies (20%); named syndromes, sequences, and associations (19%); and gastrointestinal (14%), cardiovascular (11%), and nervous system (10%) anomalies. Infants with major birth defects had a higher mortality rate (58% vs 13%, P <.001) and a higher rate of major surgery (29% vs 5%, P <.001) than infants without such defects. Infants with major birth defects accounted for 16.3% of deaths and 18.9% of major surgical procedures but only for 2.9% of total hospital days.

CONCLUSIONS

Major birth defects accounted for 16% of all deaths in VLBW infants. However, they accounted for a low proportion of total hospital days.

Infant mortality and congenital anomalies from 1950 to 1994: an international perspective

STUDY OBJECTIVE

To provide an international perspective on the impact of congenital anomalies on infant mortality from 1950 to 1994.

DESIGN

Population-based study based on data obtained from vital statistics reported to the World Health Organisation.

SETTINGS

36 countries from Europe, the Middle East, the Americas, Asia, and the South Pacific.

RESULTS

On average, infant mortality declined 68.8 per cent from 1950 to 1994. In the countries studied, infant mortality attributable to congenital anomalies decreased by 33.4 per cent, although it recently increased in some countries in Central and Latin America and in Eastern Europe. Anomalies of the heart and of the central nervous system accounted for 48.9 per cent of infant deaths attributable to congenital anomalies. During 1990-1994, infant mortality attributable to congenital anomalies was inversely correlated to the per capita gross domestic product in the countries studied. At the same time, the proportion of infant deaths attributable to congenital malformations was directly correlated with the per capita gross domestic product.

CONCLUSIONS

Congenital malformations account for an increasing proportion of infant deaths in both developed and developing countries. Infant mortality attributable to congenital anomalies is higher in poorer countries although as a proportion of infant deaths it is greater in wealthier countries. Conditions such as spina bifida, whose occurrence can be reduced through preventive strategies, still cause many infant deaths. The apparent increase of infant mortality because of congenital anomalies in some countries should be investigated to confirm the finding, find the causes, and provide prevention opportunities.