Trends in the Prevalences of Selected Birth Defects in Korea (2008⁻2014)

Neurodevelopmental outcomes among children with congenital gastrointestinal anomalies using Korean National Health Insurance claims data

This study investigated neurodevelopment and risk factors in children surgically treated for congenital gastrointestinal anomalies (CGIA), excluding those with known high-risk factors such as low birth weight or chromosomal anomalies. Data of children born between 2008 and 2015 who underwent surgical treatment for CGIA were retrieved from the Korean National Health Insurance Database. CGIA included esophageal atresia, duodenal atresia, jejunoileal atresia, anorectal malformations, and congenital megacolon. Neurodevelopmental impairment (NDI) was defined as Korean Ages and Stages Questionnaire scores below the determined cut-off or Korean Developmental Screening Test scores < 2 standard deviations at 3 years of age. Children with CGIA had a significantly higher risk of NDI than controls (6.2% vs. 2.7%, p < 0.001). Growth failure was correlated with NDI. Longer durations of oxygen support (adjusted odds ratio [aOR], 1.037; 95% confidence interval [CI], 1.013-1.063), mechanical ventilation (aOR, 1.053; 95% CI, 1.018-1.089), and number of surgeries (aOR, 1.137; 95% CI, 1.016-1.273) were significantly associated with NDI. These findings emphasize that cautious yet proactive neurodevelopmental monitoring is crucial in affected children, ensuring timely intervention and that excessive concern among families is unnecessary.

Prevalence of congenital cryptorchidism in China: A nationwide population-based surveillance study, 2007-2021

BACKGROUND

Despite cryptorchidism being a common genital abnormality in male newborns with significant prevalence variations globally, there is a notable scarcity of epidemiological data on this condition in China.

OBJECTIVE

This study aimed to delineate the prevalence pattern of cryptorchidism in Chinese population over the past 15 years using nationwide surveillance data.

MATERIALS AND METHODS

Data from the China National Population-based Birth Defects Surveillance System (2007-2021) were analyzed to calculate the prevalence rates of cryptorchidism, stratified by birth year, maternal age, maternal residence, and geographic region. Adjusted prevalence rate ratios were computed using Poisson regression, while trends in prevalence and average annual percent change (AAPC) were assessed using the joinpoint regression model.

RESULTS

During the study period, a total of 1,833 cases of cryptorchidism were identified among 2,565,964 full-term male births, resulting in prevalence rates of 7.14, 5.60, and 1.54 per 10,000 births for overall, isolated, and associated cryptorchidism, respectively. The overall prevalence increased from 3.86 to 11.20 per 10,000 births, with an AAPC of 7.9% (95% confidence interval: 5.5-11.0). Significant variations were observed across maternal age (< 20 years, 7.62/10,000; 20-24 years, 6.14/10,000; 25-29 years, 6.96/10,000; 30-34 years, 7.48/10,000; ≥35 years, 9.22/10,000), maternal residence (urban vs. rural, 10.99/10,000 vs. 2.86/10,000), and geographic region (eastern, 12.38/10,000; central, 2.36/10,000; western, 2.63/10,000). Approximately one-third of cryptorchidism cases were bilaterally, while two-thirds were unilateral. Commonly observed associated abnormalities included congenital hydrocele testis, as well as anomalies in the genital organs, circulatory system, and musculoskeletal system.

CONCLUSION

Despite lower rates compared to other countries, the increasing trend in prevalence of cryptorchidism necessitates further investigation and intervention.

Translation and validation of the Korean version of the QUAlity of Life Assessment in Spina bifida for Teenagers (QUALAS-T-K)

PURPOSE

The Quality of Life Assessment in Spina bifida for Teenagers (QUALAS-T) is a tool used to evaluate health-related quality of life (HRQOL) in adolescents with spina bifida (SB). The purpose of this study was to translate the QUALAS-T into Korean and validate its Korean version (QUALAS-T-K).

METHODS

Translation and validation processes were carried out in accordance with a specified protocol, including forward and back translation, a content validity study, and a main study. The tool's reliability was evaluated based on its internal consistency and stability. Factor analysis was conducted, and convergent validity was confirmed using the KIDSCREEN-27.

RESULTS

Of the 59 participants, 35 had lipomyelomeningoceles. Confirmatory factor analysis confirmed that QUALAS-T-K had the same structure as QUALAS-T. The QUALAS-T-K showed excellent internal consistency (α: 0.872-0.893, ω: 0.875-0.885), test-retest reliability (ICC:0.84-0.92), and weak to strong correlations with the KIDSCREEN-27.

CONCLUSIONS

The QUALAS-T-K, developed by reflecting on the characteristics of SB and considering the applicability of Korean cultural characteristics and clinical practice, is a convenient and reliable tool with excellent internal consistency and stability. This could be a useful tool in clinical and research settings for HRQOL evaluation of adolescents with SB.

Prevalence and death rate of birth defects from population-based surveillance in Hunan Province, China, 2010-2020

To describe the prevalence and death rate of birth defects from population-based surveillance in Hunan Province, China. Data were obtained from the population-based Birth Defects Surveillance System in Hunan Province, China (2010-2020). The surveillance population included all live births, stillbirths, infant deaths, and legal terminations of pregnancy from 28 weeks of gestation to 42 days after birth between 2010 and 2020 when the mother resided in the surveillance area (Liuyang County and Shifeng District, Hunan Province). The prevalence of birth defects is the number of birth defects per 1000 infants (‰). The death rate of birth defects is the number of deaths attributable to birth defects per 100 birth defects (%). The prevalence and death rate with 95% confidence intervals (CI) were calculated by the log-binomial method. Crude odds ratios (ORs) were calculated to examine the association of each demographic characteristic with birth defects. Our study included 228,444 infants, and 4453 birth defects were identified, with a prevalence of 19.49‰ (95%CI 18.92-20.07). Congenital heart defects were the most common specific defects (5.29‰), followed by limb defects (4.01‰). Birth defects were more common in males than females (22.34‰ vs. 16.26‰, OR = 1.38, 95%CI 1.30-1.47), in premature birth than not (91.82‰ vs. 16.14‰, OR = 6.16, 95%CI 5.72-6.65), in birth weight < 2500 g (98.26‰ vs. 16.22‰, OR = 6.61, 95%CI 6.11-7.15) or > 4000 g (19.48‰ vs. 16.22‰, OR = 1.21, 95%CI 1.03-1.42) than birth weight 2500-4000 g, in hospitalized deliveries than other institutions (22.16‰ vs. 11.74‰, OR = 1.91, 95%CI 1.76-2.07), in multiple births than singletons (28.50‰ vs. 19.28‰, OR = 1.49, 95%CI 1.27-1.76), in maternal age < 20 years (26.33‰ vs. 18.69‰, OR = 1.42, 95%CI 1.15-1.76) or >  = 35 years (24.31‰ vs. 18.69‰, OR = 1.31, 95%CI 1.18-1.45) than maternal age 25-29 years, and in number of pregnancies >  = 4 (22.91‰ vs. 18.92‰, OR = 1.22, 95%CI 1.10-1.35) than the first pregnancy. A total of 747 deaths attributable to birth defects were identified, including 603 (80.72%) stillbirths, 75 (10.04%) deaths within 7 days after birth, 46 (6.16%) deaths in 7-27 days after birth, 23 (3.08%) deaths in 28-42 days after birth. The death rate of birth defects was 16.78% (95%CI 15.57-17.98). Deaths attributable to birth defects accounted for 51.09% (747/1462) of all deaths. Central nervous system defects had the highest death rate (90.27%), and neonatal genetic metabolic defects had the lowest death rate (0.39%). In summary, we have described the prevalence and epidemiology of birth defects from population-based surveillance in Hunan Province, China, 2010-2020. There were differences in the prevalence and death rate of birth defects between population-based surveillance and hospital-based surveillance.

Epidemiology of congenital malformations of the external ear in Hunan Province, China, from 2016 to 2020

To describe the epidemiology of congenital malformations of the external ear (CMEE). Data were obtained from the Birth Defects Surveillance System in Hunan Province, China, 2016 to 2020. The prevalence of CMEEs is defined as the number of cases per 1000 fetuses (births and deaths at 28 weeks of gestation and beyond) (unit: ‰). Prevalence and 95% confidence intervals (CI) were calculated by the log-binomial method. Chi-square trend tests (χ2trend) were used to determine trends in prevalence by year. P < .05 was considered statistically significant. Crude odds ratios (ORs) were calculated to examine the association of sex, residence, and maternal age with CMEEs. Our study included 847,755 fetuses, and 14,459 birth defects were identified, including 1227 CMEEs (accounted for 8.49% of birth defects). The prevalences of birth defects and CMEEs were 17.06‰ (95%CI: 16.78-17.33) and 1.45‰ (95%CI: 1.37-1.53), respectively. A total of 185 microtia-anotias were identified, accounting for 15.08% of CMEEs, with a prevalence of 0.22‰ (95%CI: 0.19-0.25). And 1042 other CMEEs were identified, accounting for 84.92% of CMEEs. From 2016 to 2020, the prevalences of birth defects were 18.20‰, 18.00‰, 16.31‰, 16.03‰, and 16.47‰, respectively, showing a downward trend (χ2trend =8.45, P < .01); the prevalences of CMEEs were 1.19‰, 1.62‰, 1.80‰, 1.21‰, and 1.35‰, respectively, with no significant trend (χ2trend =0.09, P = .77). CMEEs were more common in males than females (1.60‰ vs 1.27‰, OR = 1.26, 95%CI: 1.12-1.41), in urban areas than in rural areas (1.77‰ vs 1.23‰, OR = 1.45, 95%CI: 1.29-1.62). The prevalences of CMEEs for maternal age < 20, 20-24, 25-29, 30-34, and ≥ 35 were 1.75‰, 1.27‰, 1.44‰, 1.47‰, and 1.58‰, respectively, with no significant difference (P > .05, reference: 25-29). Most CMEEs were diagnosed by clinical examinations (92.34%), and most CMEEs were diagnosed postpartum (within 7 days) (96.25%). In summary, we have presented the epidemiology of CMEEs in Hunan Province, China. CMEEs were more common in males than females, in urban areas than rural areas, whereas there was no significant difference in prevalence of CMEEs by maternal age. We inferred that CMEEs may be mainly related to genetics, and the mechanism needs to be examined in the future.

Update from a cohort study for birth defects in Hunan Province, China, 2010-2020

To define the relationship between sex, residence, maternal age, and a broad range of birth defects by conducting a comprehensive cross-analysis based on up-to-date data. Data were obtained from the Birth Defects Surveillance System in Hunan Province, China, 2010-2020. Prevalences of birth defects (number of cases per 10,000 fetuses (births and deaths at 28 weeks of gestation and beyond)) with 95% confidence intervals (CI) were calculated by sex, residence, maternal age, year, and 23 specific defects. Cross-analysis of sex, residence, and maternal age was conducted, and crude odds ratios (ORs) were calculated to examine the association of each maternal characteristic with birth defects. A total of 1,619,376 fetuses and 30,596 birth defects were identified. The prevalence of birth defects was 188.94/10,000 (95% CI 186.82-191.05). Birth defects were more frequent in males than females (210.46 vs. 163.03/10,000, OR = 1.30, 95% CI 1.27-1.33), in urban areas than in rural areas (223.61 vs. 162.90/10,000, OR = 1.38, 95% CI 1.35-1.41), and in mothers ≥ 35 than mothers 25-29 (206.35 vs. 187.79/10,000, OR = 1.10, 95% CI 1.06-1.14). Cross-analysis showed that the prevalence of birth defects was higher in urban females than in rural males (194.53 vs. 182.25/10,000), the difference in prevalence between males and females was more significant for maternal age < 20 compared to other age groups (OR = 1.64, 95% CI 1.37-1.95), and the prevalence difference between urban and rural areas is more significant for maternal age 25-34 compared to other age groups (OR = 1.49, 95% CI 1.43-1.57). Cleft palates were more frequent in males, and nine specific defects were more frequent in females. Five specific defects were more frequent in rural areas, and eight were more frequent in urban areas. Compared to mothers 25-29, five specific defects were more frequent in mothers < 20, seven specific defects were more frequent in mothers 20-24, two specific defects were more frequent in mothers 30-34, and ten specific defects were more frequent in mothers ≥ 35. Our data indicate that sex, residence, and maternal age differences in the prevalences of birth defects and most specific defects are common. We have found some new epidemiological characteristics of birth defects using cross-analysis, such as residence is the determining factor for the prevalence of birth defects, the difference in prevalence between males and females was more significant for maternal age < 20 compared to other age groups, the prevalence difference between urban and rural areas is more significant for maternal age 25-34 compared to other age groups. And differences in the epidemiological characteristics of some specific defects from previous studies. Future studies should examine mechanisms. Our findings contributed to clinical counseling and advancing research on the risk factors for birth defects.

Optimal Protocols and Management of Clinical and Genomic Data Collection to Assist in the Early Diagnosis and Treatment of Multiple Congenital Anomalies

Standardized protocols have been designed and developed specifically for clinical information collection and obtaining trio genomic information from infants affected with congenital anomalies (CA) and their parents, as well as securing human biological resources. The protocols include clinical and genomic information collection on multiple CA that were difficult to diagnose using pre-existing screening methods. We obtained human-derived resources and genomic information from 138 cases, including 45 families of infants with CA and their parent trios. For the clinical information collection protocol, criteria for target patient selection and a consent system for collecting and utilizing research resources are crucial. Whole genome sequencing data were generated for all participants, and standardized protocols were developed for resource collection and manufacturing. We recorded the phenotype information according to the Human Phenotype Ontology term, and epidemiological information was collected through an environmental factor questionnaire. Updating and recording of clinical symptoms and genetic information that have been newly added or changed over time are significant. The protocols enabled long-term tracking by including the growth and development status that reflect the important characteristics of newborns. Using these clinical and genetic information collection protocols for CA, an essential platform for early genetic diagnosis and diagnostic research can be established, and new genetic diagnostic guidelines can be presented in the near future.

Major Congenital Anomalies in Korean Livebirths in 2013-2014: Based on the National Health Insurance Database

BACKGROUND

In Korea, there have been no reports comparing the prevalence of major congenital anomalies with other countries and no reports on surgical treatment and long-term mortality. We investigated the prevalence of 67 major congenital anomalies in Korea and compared the prevalence with that of the European network of population-based registries for the epidemiological surveillance of congenital anomalies (EUROCAT). We also investigated the mortality and age at death, the proportion of preterm births, and the surgical rate for the 67 major congenital anomalies.

METHODS

Korean National Health Insurance claim data were obtained for neonates born in 2013-2014 and admitted within one-year-old. Sixty-seven major congenital anomalies were defined by medical diagnoses classified by International Classification of Diseases-10 codes according to the EUROCAT definition version 2014. Mortality and surgery were defined if any death or surgery claim code was confirmed until 2020. Poisson distribution was used to calculate the 95% confidence interval of the congenital anomaly prevalence.

RESULTS

The total prevalence of the 67 major anomalies was 433.5/10,000 livebirths. When compared with the prevalence of each major anomaly in EUROCAT, the prevalence of spina bifida, atrial septal defect (ASD), congenital megacolon, hip dislocation and/or dysplasia and skeletal dysplasia were more than five times higher in Korea. In contrast, the prevalence of aortic atresia/interrupted aortic arch and gastroschisis was less than one-fifth in Korea. The proportion of preterm births was 15.7%; however, more than 40% of infants with anencephaly, annular pancreas and gastroschisis were preterm infants. Additionally, 29.2% of the major anomalies were admitted to the neonatal intensive care units at birth, and 25.6% received surgical operation. The mortality rate was 1.7%, and 78.2% of the deaths occurred within the first year of life. However, in neonates with tricuspid valve atresia and stenosis, duodenal atresia or stenosis, and diaphragmatic hernia, more than half died within their first month of life. ASD and ventricular septal defect were the most common anomalies, and trisomy 18 and hypoplastic left heart syndrome were the most fatal anomalies. All infants with aortic atresia/interrupted aortic arch and conjoined twins received surgery.

CONCLUSION

The proportion of surgeries, preterm births and mortality was high in infants with major congenital anomalies. The establishment of a national registry of congenital anomalies and systematic support by national medical policies are needed for infants with major congenital anomalies in Korea.

Renal agenesis: A meta-analysis of its prevalence and clinical characteristics based on 15 641 184 patients

Our objective was to analyse the newest relevant data on worldwide prevalence and associated symptoms of renal agenesis (RA). This meta-analysis builds on previous systematic reviews to include bilateral RA, its symptoms and data on gender, unilateral RA and anomaly location prevalence. Review of available data included records in English and other languages from PubMed, Embase, ScienceDirect, Web of Science, SciELO, BIOSIS, Current Content Connect Korean Journal Database and Russian Citation Index and Google. A total of 15 641 184 patients were analysed in relation to the prevalence of RA. The pooled prevalence of RA was 0.03% (95% CI: 0.03%-0.04%). Based on 500 subjects, a pooled prevalence of 47.96% (95% CI: 31.55%-64.58%) for unilateral and 52.04% (95% CI: 35.42%-68.45%) for bilateral RA has been set. Our study presents the newest generalized findings on bilateral RA. There appears to be universal disease and symptom prevalence with minor differences between world regions, although quality of future observational research should include genomic data. This will provide even further insight into the prognosis of various renal anomalies and their etiologies.

Epidemiology of birth defects in a national hospital-based birth defect surveillance spot in Southern Jiangsu, China, 2014-2018

Objective

As the only hospital-based national surveillance spot of birth defects (BDs) in Changzhou city located in the economically developed eastern part of China, Changzhou Maternal and Child Health Care Hospital has encountered serious challenges in BD prevention. This study aimed to describe the epidemiology of total BDs born in the hospital from 2014 to 2018.

Methods

The data were collected from the national hospital-based birth defect surveillance system. BD prevalence was calculated by Poisson distribution. Trends of prevalence and the associations regarding information with BDs were analyzed by Poisson regression.

Results

The reported prevalence of total BDs was 313.92 (95% confidence interval [CI]: 299.59-328.76) per 10,000 perinatal infants (PIs), while the perinatal prevalence of BD was 160.19 (95% CI: 150.00-170.89) per 10,000 PIs. A remarkable uptrend in the prevalence of BDs was noticed with a prevalence rate ratio (PRR) of 1.09 (95% CI: 1.04-1.14) and 1.13 (95% CI: 1.09-1.16), respectively. Congenital heart disease (CHD), cleft lip with or without cleft palate (CL/P), congenital malformation of the kidney (CMK), polydactyly, Down syndrome (DS), cystic hygroma, neural tube defect (NTD), and congenital talipes equinovarus (CTE) were common types of total BDs. Mothers living in the urban area (PRR = 1.67, 95% CI:1.50-1.87), male fetuses (PRR = 1.16, 95% CI: 1.05-1.28), and maternal age younger than 20 (PRR = 2.28, 95% CI: 1.60-3.25) and 25 years (PRR = 1.41, 95% CI: 1.22-1.63) or older than 35 years (PRR = 1.18, 95% CI: 1.00-1.40) were risk factors for BD occurrence.

Conclusion

The reported prevalence of total BDs was nearly two times higher than the perinatal prevalence of BDs in PIs, and the ranks of total BDs and BDs in PIs were different. Mothers living in the urban area, male fetuses, and maternal ages younger than 25 or older than 35 years were risk factors for BD incidence. Thus, improving prenatal examination technology, expanding the surveillance time quantum of BDs, and keeping maternal health may be warranted.

The association between nurse continuity and hypospadias repair patient outcomes: A retrospective study

BACKGROUND

Recently, nurse continuity, the intensity and consistency of a patient's exposure to nurses during hospitalization, has been shown to be associated with patient outcomes. However, little is known about how nurse continuity is related to patients' surgical outcomes.

AIMS

To examine the association between nurse continuity and outcomes of hypospadias repair to clarify the importance of nurse continuity as a nursing practice.

DESIGN

This is a retrospective study.

METHODS

We analysed the data from electronic health records of patients under 1 year who had undergone proximal hypospadias repair between January 2014 and December 2016. Nurse continuity was measured using the Continuity of Care Index. Since approximately half of the patients reportedly needed further operations in the long term, the primary outcome was whether patients with proximal hypospadias repair had two or more additional operations within 3 years of discharge.

RESULTS

The rate of undergoing two or more follow-up operations in 3 years was significantly higher in patients with low nurse continuity-38.6% versus 12.8% for high continuity.

CONCLUSION

This study identified nurse continuity as an important factor related to patients' surgical outcomes. These findings suggest that nurse continuity be considered an important nursing strategy for patient outcomes and further research is needed on this topic.

IMPACT STATEMENT

As empirical evidence regarding the association between nurse continuity and patient outcomes grows, nurse managers and policymakers should view nurse continuity as a critical factor for positive patient outcomes when considering nursing workforce regulations.

NO PATIENT OR PUBLIC CONTRIBUTION

The data for this study were obtained from electronic health records, and the entire process of this study did not involve patient or public participation.

Reducing Birth Defects by Decreasing the Prevalence of Maternal Chronic Diseases-Evaluated by Linked National Registration Dataset

Birth defects (BDs) are an important cause of abortion, stillbirth, and infant mortality that may cause lifelong disability. The defects can be caused by genetics, environmental exposure, or maternal chronic diseases. We conducted a study to analyze the association between maternal chronic diseases and BDs and to evaluate the effect of decreasing the prevalence of maternal chronic diseases on reducing BDs. The data of newborns and their mothers were concatenated and analyzed from three national population databases: the National Health Insurance Research Database, the Birth Certificate Application, and the Birth Registration Database in Taiwan during the period of 2005 to 2014. Codes 740-759 of the International Classification of Diseases 9th Revision—Clinical Modification (ICD-9-CM) were used as the diagnosis of BDs. The prevalence of BDs was 2.72%. Mothers with cardiovascular diseases, hypertension, anemia, genitourinary tract infections, renal diseases, neurotic or psychotic disorders, gestational diabetes mellitus (DM), and pregestational type 1 or type 2 DM had a significantly higher prevalence of BDs. The population attributable risk percent (PAR%) of BDs was 1.63%, 0.55%, 0.18%, 1.06%, 0.45%, 0.22%, 0.48%, and 0.24% for maternal hypertension, cardiovascular disease, renal disease, genitourinary infection, anemia, neurotic and psychotic disorders, gestational DM, and pregestational type 1 or type 2 DM, respectively. The percentage change (−1%, −5%, and −10% of prevalence in 2034 compared with the prevalence in 2005−2014) of maternal disease and the predicted number of live births was used to estimate the decrease in the number of newly diagnosed BDs in 2034. By using the middle-estimated number of live births in 2034, we predicted that the number of BDs would decrease by 302, 102, 33, 196, 83, 41, 89, and 44 with a −5% prevalence of maternal hypertension, cardiovascular disease, renal disease, genitourinary infection, anemia, neurotic and psychotic disorders, gestational DM, and pregestational type 1 or type 2 DM, respectively. We conclude that mothers with chronic diseases, including cardiovascular diseases, hypertension, anemia, genitourinary tract infections, renal diseases, neurotic or psychotic disorders, gestational DM, and pregestational type 1 or type 2 DM, have a significantly higher (p < 0.01) prevalence of having offspring with BDs. Mothers with chronic diseases are associated with BDs. It is very important to set up a policy to decrease the prevalence of these maternal chronic diseases; then, we can reduce the incidence of BDs.

Global Epidemiology of Craniosynostosis: A Systematic Review and Meta-Analysis

OBJECTIVE

Craniosynostosis leads to craniofacial deformity and may result in raised intracranial pressure, neurocognitive deficits, and psychosocial issues if left untreated. The global epidemiology of craniosynostosis is unknown. We conducted a meta-analysis to estimate global birth prevalence.

METHODS

PubMed, Embase, and Scopus were searched. Articles were screened by title and abstract and then full text. Meta-analysis of birth prevalence was conducted. Birth prevalence figures were combined with metrics detailing the number of births in 2019 to estimate the number of children worldwide born with craniosynostosis annually.

RESULTS

Of 1378 resultant articles, 24 studies were included, including 20 providing data for craniosynostosis overall and 9 for nonsyndromic craniosynostosis. World Health Organization regions of included studies were 9 (37.5%) European Region, 8 (33.3%) Region of the Americas, 4 (16.7%) Western Pacific region, 2 (8.3%) African Region, and 1 (4.2%) Eastern Mediterranean Region. Lower middle-income countries represented only 4% of study manuscripts. The overall birth prevalence of craniosynostosis was 5.9 per 10,000 live births (20 studies; 95% confidence interval [CI]: 3.9, 8.4; I² = 100%). The birth prevalence of nonsyndromic craniosynostosis was 5.2 per 10,000 live births (9 studies; 95% CI: 3.4, 7.3; I² = 98%). The number of children born globally with craniosynostosis in 2019 was estimated to be 84,665 (95% CI: 55,965, 120,540), including 72,857 (95% CI: 47,637, 120,280) with nonsyndromic craniosynostosis.

CONCLUSIONS

Craniosynostosis is a common condition that affects the neurocognitive and craniofacial skeletal development of children worldwide. Initiatives to scale up capacity for craniosynostosis epidemiologic research and clinical care are warranted, particularly in low- and middle-income countries.

Association of air pollution exposure with exercise-induced oxygen desaturation in COPD

BACKGROUND

There is a link between exposure to air pollution and the increased prevalence of chronic obstructive pulmonary disease (COPD) and declining pulmonary function, but the association with O₂ desaturation during exercise in COPD patients with emphysema is unclear. Our aims were to estimate the prevalence of O₂ desaturation during exercise in patients with COPD, and determine the association of exposure to air pollution with exercise-induced desaturation (EID), the degree of emphysema, and dynamic hyperinflation (DH).

METHODS

We assessed the effects of 10-year prior to the HRCT assessment and 7 days prior to the six-minute walking test exposure to particulate matter with an aerodynamic diameter of < 10 µm (PM₁₀) or of < 2.5 µM (PM_2.5), nitrogen dioxide (NO₂), and ozone (O₃) in patients with emphysema in this retrospective cohort study. EID was defined as a nadir standard pulse oximetry (SpO₂) level of < 90% or a delta (△)SpO₂ level of ≥ 4%. Ambient air pollutant (PM_2.5, PM₁₀, O₃, and NO₂) data were obtained from Taiwan Environmental Protection Administration (EPA) air-monitoring stations, usually within 10 km to each participant's home address.

RESULTS

We recruited 141 subjects with emphysema. 41.1% of patients with emphysema exhibited EID, and patients with EID had more dyspnea, worse lung function, more severe emphysema, more frequent acute exacerbations, managed a shorter walking distance, had DH, and greater long-term exposure to air pollution than those without EID. We observed that levels of 10-year concentrations of PM₁₀, PM_2.5, and NO₂ were significantly associated with EID, PM₁₀ and PM_2.5 were associated with the severity of emphysema, and associated with DH in patients with emphysema. In contrast, short-term exposure did not have any effect on patients.

CONCLUSION

Long-term exposure to ambient PM₁₀, PM_2.5 and NO₂, but not O₃, was associated with EID.

Prevalence and patterns of birth defects among newborns in southwestern Ethiopia: a retrospective study

Introduction

prenatal development could be considered normal or abnormal. Abnormal development occurs because of interference of normal development from genetic disorders, environmental factors, and multifactorial inheritances during the critical period of embryogenesis. The present study was aimed at evaluating the prevalence and patterns of birth defects among newborns in southwestern Ethiopia.

Methods

institutions-based cross-sectional study design was conducted in six purposively selected hospitals in southwestern Ethiopia based on their caseload. The study included data's from 2011 to 2015, during which 45,951 deliveries were recorded. All records of births in the selected hospitals were screened from medical records to identify the presence and types of birth defects.

Results

out of twenty-one different birth defects identified, nearly half of them belong to anencephaly and hydrocephalus. Five types of birth defects, namely: anencephaly (25.0%), hydrocephalus (24.6%), spina bifida (13.1%), meningomyelocele (7.1%), and umbilical hernia (4.8%) accounted for about three-fourths (75%) of all recorded birth defects. The prevalence rate of birth defects at birth was 55 per 10,000 births.

Conclusion

in the present study, the neural tube defects were identified to be the most prevalent. Nearly equal proportions of birth defects occurred among male and female newborns. The majority of the mothers who gave birth to newborns with birth defects were younger than 35 years. The high prevalence of birth defects revealed in this study call for the need to implement urgent prevention strategies including but not limited to the provision of sustained family planning, youth education and antenatal care services, and strict observation of rational medication use during pregnancy to curb the possible occurrences of the birth defect.

Environmental and Genetic Risk Factors of Congenital Anomalies: an Umbrella Review of Systematic Reviews and Meta-Analyses

BACKGROUND

The prevalence of congenital anomalies in newborns in South Korea was 272.9 per 100,000 in 2005, and 314.7 per 100,000 in 2006. In other studies, the prevalence of congenital anomalies in South Korea was equivalent to 286.9 per 10,000 livebirths in 2006, while it was estimated 446.3 per 10,000 births during the period from 2008 to 2014. Several systematic reviews and meta-analyses analyzing the factors contributing to congenital anomalies have been reported, but comprehensive umbrella reviews are lacking.

METHODS

We searched PubMed, Google Scholar, Cochrane, and EMBASE databases up to July 1, 2019, for systematic reviews and meta-analyses that investigated the effects of environmental and genetic factors on any type of congenital anomalies. We categorized 8 subgroups of congenital anomalies classified according to the 10th revision of the International Statistical Classification of Diseases (ICD-10). Two researchers independently searched the literature, retrieved the data, and evaluated the quality of each study.

RESULTS

We reviewed 66 systematic reviews and meta-analyses that investigated the association between non-genetic or genetic risk factors and congenital anomalies. Overall, 269 associations and 128 associations were considered for environmental and genetic risk factors, respectively. Congenital anomalies based on congenital heart diseases, cleft lip and palate, and others were associated with environmental risk factors based on maternal exposure to environmental exposures (air pollution, toxic chemicals), parental smoking, maternal history (infectious diseases during pregnancy, pregestational and gestational diabetes mellitus, and gestational diabetes mellitus), maternal obesity, maternal drug intake, pregnancy through artificial reproductive technologies, and socioeconomic factors. The association of maternal alcohol or coffee consumption with congenital anomalies was not significant, and maternal folic acid supplementation had a preventive effect on congenital heart defects. Genes or genetic loci associated with congenital anomalies included MTHFR, MTRR and MTR, GATA4, NKX2-5, SRD5A2, CFTR, and 1p22 and 20q12 anomalies.

CONCLUSION

This study provides a wide perspective on the distribution of environmental and genetic risk factors of congenital anomalies, thus suggesting future studies and providing health policy implications.

Prenatal Exposure to Alcohol, Tobacco, and Coffee: Associated Congenital Complications and Adverse Birth Outcomes

A few studies to date have examined the association between prenatal exposure to alcohol, tobacco, and coffee, and congenital complications/adverse birth outcomes among South Korean populations. Thus, this study analyzed the data of 1675 Korean women with birth experience within the last 3 years for pregnancy-related health and nutritional behaviors and relative outcomes. During their pregnancies, 11.58% of the study population consumed alcohol at least once, 1.43% drank throughout all three trimesters, 1.13% smoked, 25.43% were exposed to secondhand smoking, and 28.18% consumed 3 coffees or more every day. Prenatal alcohol exposure was associated with 11.24 times increased risk of birth defects/disabilities [Odds Ratio (OR): 11.24, 95% Confidence Interval (CI) 1.07-117.86] and 10.66 times increased risk of inherited metabolic diseases (OR: 10.66, 95% CI: 1.08-104.82). Prenatal secondhand smoke exposure (OR: 1.62, 95% CI: 1.01-2.62) and coffee consumption (OR: 1.92, 95% CI: 1.22-3.03) was associated with increased risk of low birth weight. Such results were in alignment with that of previous studies and confirmed that prenatal alcohol, tobacco, and coffee exposure can have detrimental neonatal and maternal consequences.

Changes in the prevalence of index diseases in pediatric surgery: case analysis of single national children’s hospital

Pusan National University Children’s Hospital (PNUCH) opened in November 2008 as the second National Children’s Hospital in Korea and celebrated its 10th anniversary in 2018. In the last decade, birth rates and pediatric populations have been declining sharply and has been more serious in Busan, Ulsan, and Gyeongsangnam-do where the PNUCH is located, affecting the prevalence of index diseases. The number of the index diseases was investigated by year according to changes in the population. Patients who underwent surgery at PNUCH for 10 years were included. Changes in pediatric population and the number of live births were analyzed using the data from Statistics Korea. The number of the index diseases was analyzed retrospectively through the review of electronic medical records. Statistical analysis was performed through Poisson regression. The number of live births and pediatric population decreased from 69,528 to 48,600 (30.1%) and 1,880,284 to 1,444,961 (23.2%), respectively. Operations of pediatric surgery decreased by 32.3% compared to that during the peak season, but the prevalence rate ratio of the pediatric population increased to 1.03 (<i>P</i><0.001). The number of emergency operation increased due to the largest surge in acute appendicitis operations. Both esophageal atresia and Hirschsprung disease decreased, while hypertrophic pyloric stenosis significantly increased. The absolute number of pediatric surgery cases decreased. However, considering the changes in pediatric population and the number of live births, the relative number of pediatric surgery cases does not changed. The decrease in the number of each disease would be related to the decrease in pediatric population and the number of live births. We should consider the increase of emergency operations such as acute appendicitis.

Illness Experiences of Adults with Spina Bifida: Protecting the Whole Self

PURPOSE

To understand and describe the illness experiences of adults with spina bifida (SB) which is an incurable birth defect and chronic condition that must be managed throughout life.

METHODS

A qualitative study using grounded theory was adopted. Data were collected through individual interviews with 16 adults with SB between 2016 and 2017 in South Korea. All interviews were audiotaped, and the transcribed data were analyzed using constant comparative analysis.

RESULTS

The basic socio-psychological process that underlies the illness experiences of adults with SB was identified as protecting the whole self. This consists of three stages: strict self-concealment, attempting self-disclosure, and balancing between self-concealment and self-disclosure. These stages reveal a process of establishing a firm sense of self by freeing oneself from the shame and stigma of society. Three different patterns of living emerged as a result: living as a non-disabled person, living as a marginal person between non-disabled and disabled, and living as a disabled person.

CONCLUSION

Adults with SB struggle to protect their whole self while managing their chronic conditions by having to constantly balance between self-concealment and self-disclosure. Intervention for adults with SB needs to be based on the stage of sociopsychological maturation. In the early stage, intervention needs to be focused on self-concealment to help establish a firm sense of self. On the other hand, in the later stage when psychological maturity occurs, an intervention that focuses on self-disclosure would be helpful so as not to be isolated from society.

The birth prevalence of selected major congenital anomalies: Six-year's experience in a tertiary care maternity hospital

Aim:

To evaluate the birth prevalence of specifically selected major congenital anomalies and to determine the correlated neonatal and maternal characteristics.

Material and Methods:

Data were collected retrospectively from hospital-based records of infants who were born at 22 completed weeks of gestation with a birth weight of more than 500 g in Zekai Tahir Burak Gynecology Training and Research Hospital between 2013 and 2018. Abortions, stillbirths, and terminated pregnancies due to fetal anomalies were excluded. Average annual prevalences were calculated for each selected major congenital anomaly.

Results:

The total prevalence of congenital anomalies was 9.97 per 1000 in 102 379 live birth cohorts. The prevalence of severe congenital heart anomalies (SI-SII) was found as 21.1 per 10 000 live births. Down syndrome and meningomyelocele were the second and third most common anomalies, after congenital heart defects (13.87 and 9.97 per 10 000 live births, respectively). The prevalence of anomalies requiring specific surgery was found as 4.3 per 1000 live births. Congenital heart disease was present in 31.7% of patients who had Down syndrome. Atrioventricular septal defect accounted for 53.3% of congenital heart anomalies detected in Down syndrome. The prevalence of Down syndrome in babies of mothers aged 35 years and older was found as 46.67 per 10 000, which was significantly higher than in the group aged under 35 years (8.24 per 10 000). On the other hand, the prevalence of gastroschisis in babies of mothers aged 19 years and under was found as 5.81 per 10 000, which was higher than in the group aged 20 years and over (0.84 per 10 000).

Conclusion:

The actual magnitude of the number of births affected by congenital anomalies in Turkey is unknown. In our study, congenital heart diseases, Down syndrome, and meningomyelocele were found to be the most common congenital anomalies, respectively.

Prenatal exposure to traffic-related air pollution and risk of congenital diseases in South Korea

BACKGROUND

Previous studies have suggested links between exposure to ambient air pollutants and increased risk of congenital heart defects. However, few studies have investigated the association between other congenital diseases and traffic-related air pollution. In this study, we assessed the relationship between prenatal exposure to fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) with congenital diseases in South Korea.

METHODS

Patients with one or more congenital diseases and a control group of patients with non-infective gastroenteritis and colitis with a case:control ratio of 1:3 were obtained from the National Health Insurance Service data for 2008-2013 in South Korea. We estimated the associations of PM_2.5 and NO₂ exposures with congenital diseases using generalized estimation equations after controlling for covariates.

RESULTS

Maternal PM_2.5 exposure during the first and second trimester showed positive associations with overall congenital diseases, with changes of 14.7% (95% confidence intervals (CI), 9.3%, 20.3%) and 16.2% (95% CI, 11.0%, 21.7%), respectively, per 11.1 μg/m³ and 10.2 μg/m³ increase of PM_2.5 interquartile range (IQR). Similarly, NO₂ exposure during the first and second trimester was associated with increased numbers of overall congenital anomalies, with 8.2% (95% CI, 4.2%, 12.3%) and 15.6% (95% CI, 9.3%, 22.2%) more cases, respectively, per 10.6 ppb increase of NO₂. We found that maternal PM_2.5 exposure during the first and second trimesters of pregnancy was significantly associated with increased risk of specific congenital diseases, including subtypes affecting the circulatory, genitourinary, and musculoskeletal system. However, no significant associations were observed during the third trimester. Maternal NO₂ exposure across the entire pregnancy was associated with malformations of the musculoskeletal system.

CONCLUSIONS

Our study identified significant links between in utero exposure to PM_2.5 and NO₂ and certain congenital diseases, and suggests that stricter controls on PM_2.5 and NO₂ concentrations are required.

Epidemiology of birth defects based on a birth defect surveillance system in Southern Jiangsu, China, 2014-2018

Introduction: Changzhou has been confronted with great challenges in birth defects (BDs) prevention, as the prevalence rates of BDs in Changzhou increased rapidly. The aims of this study were to describe the epidemiology of BDs in perinatal infants (PIs, including dead fetus, stillbirth, or live birth between 28 weeks of gestation and 7 days after birth) in Changzhou during the period from 2014 to 2018.Methods: The BD surveillance data of PIs were collected from 56 hospitals of Changzhou. The prevalence rate of BDs with 95% confidence interval (CI) were calculated by Poisson distribution. Univariate and multivariate Poisson regression was performed to identify the changing trends of prevalence rates of BDs by year and the association of regarding BD characteristics including year, infant gender, maternal age, and season with BDs successively.Results: From 2014 to 2018, there were a total of 238,712 PIs of which 1707 had BDs, with the average prevalence of 71.509 per 10,000 PIs, showing a remarkable uptrend (aPRR = 1.133, 95%CI: 1.094-1.173). The ten leading BDs were polydactyly, congenital heart defects (CHD), syndactyly, microtia, cleft lip and palate (CLP), hypospadias, cleft palate, other malformation of external ear (OMEE), congenital atresia of rectum and anus, and congenital talipes equinovarus (CTE). During the study period, the prevalence rates of polydactyly, CHD and syndactyly increased significantly (PRR = 1.195, 95%CI: 1.109-1.288, PRR = 1.194, 95%CI: 1.105-1.291, and PRR = 1.143, 95%CI: 1.007-1.297, respectively); the prevalence rates of congenital esophageal atresia decreased significantly (PRR = 0.571, 95%CI: 0.395-0.826). The risk of BDs was higher in male PIs versus female PIs (aPRR = 1.235, 95%CI: 1.123-1.358).Conclusions: A significant increase in the prevalence of BDs was detected from 2014 to 2018 in Changzhou. CHD, polydactyly, and syndactyly increased much and congenital esophageal atresia declined much. Male PIs was risk factor for occurrence of BDs. Collecting information on factors associated with BDs, setting the report time of BDs system at smaller gestational age so as to get an exact prevalence and make better prevention strategy, strengthening the publicity and education, improving the ability of monitoring, and wider use of new diagnosis technology are important to reduce the prevalence of BDs in PIs.

Changes in maternal age and prevalence of congenital anomalies during the enactment of China's universal two-child policy (2013-2017) in Zhejiang Province, China: An observational study

BACKGROUND

China implemented a partial two-child policy (2013) followed by a universal two-child policy (2015), replacing the former one-child policy mandated by the government. The changes affect many aspects of China's population as well as maternal and infant health, but their potential impact on birth defects (BDs) remains unknown. In this study, we investigated the associations of these policy changes with BDs in Zhejiang Province, China.

METHODS AND FINDINGS

We used data from the BD surveillance system in Zhejiang Province, China, which covers 90 hospitals in 30 urban districts and rural counties, capturing one-third of the total births in this province. To fully consider the time interval between conception and delivery, we defined the one-child policy period as data from 2013 (births from October 2012 to September 2013), the partial two-child policy period as data from 2015 (births from October 2014 to September 2015), and the universal two-child policy period as data from 2017 (births from October 2016 to September 2017). Data from 2009 and 2011 were also used to show the changes in the proportion of births to women with advanced maternal age (35 years and older) prior to the policy changes. Main outcome measures were changes in the proportion of mothers with advanced maternal age, prevalence of BDs, rankings of BD subtypes by prevalence, prenatal diagnosis rate, and live birth rate of BDs over time. A total of 1,260,684 births (including live births, early fetal losses, stillbirths, and early neonatal deaths) were included in the analyses. Of these, 644,973 (51.16%) births were to women from urban areas, and 615,711 (48.84%) births were to women from rural areas. In total, 135,543 (10.75%) births were to women with advanced maternal age. The proportion increased by 85.68%, from 8.52% in 2013 to 15.82% in 2017. However, it had remained stable prior to policy changes. Overall, 23,095 BDs were identified over the policy changes (2013-2017). The prevalence of BDs during 2013, 2015, and 2017 was 245.95, 264.86, and 304.36 per 10,000 births, respectively. Trisomy 21 and other chromosomal defects increased in both risk and ranking from 2013 to 2017 (crude odds ratio [95% confidence interval] 2.13 [1.75-2.60], from ranking 10th to 5th, and 3.63 [2.84-4.69], from ranking 16th to 6th, respectively). The prenatal diagnosis rate increased by 3.63 (2.2-5.1) percentage points (P < 0.001), from 31.10% to 34.72%, and identification of BDs occurred 1.88 (1.81-1.95) weeks earlier (P < 0.001). The live birth rate for infants with BDs born before 28 gestational weeks increased from 1.29% to 11.45%. The major limitations of this observational study include an inability to establish causality and the possible existence of unknown confounding factors, some of which could contribute to BDs.

CONCLUSIONS

In this study, we observed significant increases in maternal age and the prevalence of total and age-related anomalies following China's new two-child policy. Increases in live birth rate for infants with BDs born before 28 gestational weeks suggest that healthcare for very preterm births with BDs may be warranted in the future, as well as updating the definition of perinatal period.

Congenital Anomalies in Very-Low-Birth-Weight Infants: A Nationwide Cohort Study

BACKGROUND

Management of newborn infants with congenital anomalies is challenging and requires a multidisciplinary approach. The prevalence of congenital anomalies in very-low-birth-weight infants (VLBWIs; birth weight <1,500 g) has been rarely reported.

OBJECTIVES

The aim of this study was to investigate the epidemiology of congenital anomalies in VLBWIs and the association with early mortality and major morbidities.

STUDY DESIGN

A prospective cohort study was performed using data collected from 70 centers registered in the Korean Neonatal Network. Data from the VLBWIs with major congenital anomalies (n = 289) and the controls (n = 867), selected by 1:3 frequency matching for gestational age, were compared.

RESULTS

The overall prevalence of major congenital anomalies in VLBWIs was 34.9 per 1,000 live births (289/8,156). The top 2 ranked subgroups of congenital anomalies were the digestive system (31.7%) and congenital heart defects (27.7%), followed by chromosomal anomalies, genitourinary tract defect, central nervous system, other anomalies, undefined, and respiratory system. The group with congenital anomalies had a higher mortality (40.7%) than the control group (11.1%). Each subgroup of congenital anomalies, except for chromosomal anomalies, increased the risk of mortality, with the highest odds ratio associated with "other" anomalies, which includes hydrops fetalis and congenital diaphragmatic hernia. In the multivariate analysis, congenital anomaly was a risk factor for mortality, bronchopulmonary dysplasia, and severe-grade intraventricular hemorrhage. VLBWIs with congenital anomaly demonstrated impaired in-hospital growth as compared with the control group.

CONCLUSION

Congenital anomaly increased the risk of in-hospital mortality and was associated with short-term neonatal morbidities in the VLBWIs.

Birth defects in Taiwan: A 10-year nationwide population-based, cohort study

BACKGROUND/PURPOSE

Birth defects (BDs) are main causes of mortality and disability in infants and children. The aims of this study were to analyze the prevalence, types and risk factors of BDs in Taiwan.

METHODS

Data of all births (including live and stillbirths), types, characteristics, and associated risk factors of BDs were obtained from the National Birth Registry and National Health Insurance Research Data base in Taiwan between 2005 and 2014. Birth defects were coded according to International Classification of Diseases 9th Revision-Clinical Modification codes 740-759.

RESULTS

A total of 55,299 infants were diagnosed as having BDs among 2,033,004 births. The prevalence of BDs was 271.66 per 10,000 births. The prevalence of BDs did not change significantly between 2005 and 2014, there was a higher birth rate and lower BDs in 2012 (year of dragon) in Taiwan. The most common type of BDs was cardiovascular abnormalities, and ventricular septal defect was the most common disease. Extreme maternal age (<18 years or ≧30 years), preterm, and low birth weight were associated with BDs. Maternal diseases associated with BDs included hypertension, cardiovascular diseases, renal diseases, genitourinary infections, anemia, mental disorders, and diabetes mellitus.

CONCLUSION

The prevalence of BDs was 271.66 per 10,000 births. The most common types of BDs were cardiovascular abnormalities. If we can reduce maternal chronic diseases, we will decrease the prevalence of BDs.

Hypospadias Risk from Maternal Residential Exposure to Heavy Metal Hazardous Air Pollutants

Objective: Investigate whether residential prenatal exposure to heavy metal hazardous air pollutants (HMHAPs) is associated with an increased risk of hypospadias. Methods: Data on non-syndromic hypospadias cases (n = 8981) and control patients delivered in Texas were obtained from the Texas Birth Defects Registry and matched 1:10 by birth year. Average exposure concentrations of HMHAPs were obtained from the 2005 U.S. Environmental Protection Agency National-Scale Air Toxics Assessment and categorized into quintiles. Odds ratios and 95% confidence intervals were estimated. STROBE reporting guidelines were followed. Results: We observed associations between hypospadias and prenatal HMHAP exposure. Manganese demonstrated significant increased risk of hypospadias at the medium, medium-high and high exposure quintiles; lead in the medium-high and high exposure quintiles. Cadmium, mercury and nickel demonstrated a significant inverted "U-shaped" association for exposures with significant associations in the medium and medium-high quintiles but not in the medium-low and high quintiles. Arsenic and chromium demonstrated a significant bivalent association for risk of hypospadias in a lower quintile as well as a higher quintile with non-significant intermediate quintiles. Conclusions: Using data from one of the world's largest active surveillance birth defects registries, we identified significant associations between hypospadias and HMHAP exposures. These results should be used in counseling for maternal demographic risk factors as well as avoidance of heavy metals and their sources.

The effects of preconception examinations on birth defects: a population-based cohort study in Dongguan City, China

Objective: To evaluate the effect of preconception examinations programs on the prevention of birth defects in Dongguan City during 2013-2017.Methods: The data were from preconception examinations system and the birth defects surveillance system during 2013-2017. The study population included 63,175 infants born to mothers accepted preconception examinations during pregnancy (the screening group) and 649,862 infants whose mother did not check (the control group). The infants included for stillbirth, dead fetus, live birth between 28 weeks of gestation and 7 days after birth and legal pregnancy termination. The risk ratios (RRs) and 95% confidence intervals (CIs) were calculated to examine for the association between birth defects and preconception examinations. We also conducted a stratified analysis based on infant gender and disease classification, and maternal age and region.Results: The incidence of birth defects in the screening group was 134.55/10,000, while that in the control group was 241.53/10,000. Preconception examinations can effectively reduce the incidence of birth defects (BDs) (RR: 0.557, 95%CI: 0.520-0.597). Bifid spine (RR: 0.076, 95%CI: 0.011-0.545), anencephalia (RR: 0.134, 95%CI: 0.033-0.543) and anorectal atresia or stenosis (RR: 0.151, 95%CI: 0.048-0.471) were controlled best, and Down syndrome (RR: 0.684, 95%CI: 0.435-1.075) was no effect. Young maternal age (14-19 years) and old maternal age will increase the risk of birth defects. Preconception examinations had the best effect for pregnant women under 25 years of age (RR: 0.465, 95%CI: 0.387-0.559), and were relatively poor for women aged 30-34 years (RR: 0.678, 95%CI: 0.593-0.776). The incidence of the urban was significantly higher than that of the rural. The effect of preconception examinations to prevent birth defects was more effective in urban areas (RR: 0.453, 95%CI: 0.391-0.525) than in rural areas (RR: 0.577, 95%CI: 0.533-0.625). The incidence of BDs in males was higher than that in females.Conclusions: By implementing preconception examinations project, birth defects in Dongguan have been well controlled. This can provide reference for other developing countries to prevent birth defects.