[An descriptive epidemiological study on congenital clubfoot in China during 2001 to 2010].

OBJECTIVE: To understand the trend of prevalence of congenital clubfoot and its epidemiological characterisitics in China during 2001 to 2010. METHODS: The data of the perinatal children with congenital clubfoot from 2001 to 2010 in the birth defects monitoring program were collected and analyzed, and the perinatal children were defined from the pregnancy of 28 weeks to postnatal 7 days, including live births, fetal deaths and stillbirths. SPSS16.0 software was used to analyze the data. RESULTS: A total of 4,233 cases were identified with congenital clubfoot among 8 273 382 births, with a prevalence of 5.12/10(4). There was no increasing trend or decreasing trend on the prevalence of congenital clubfoot to be found in China during 2001 to 2010 (chi2 = 2. 43, P > 0.05). The prevalence of congenital clubfoot in urban and rural areas was 4.90 and 5.43 per 10 000 births respectively. The prevalence of congenital clubfoot in male and female babies was 5.31 and 4.3 per 10,000 births respectively. The prevalence of congenital clubfoot in west, middle and east region was 7.00, 4.52 and 4.27 per 10,000 births respectively. The prevalence of congenital clubfoot in south and north region was 5. 82 and 4. 34 per 10,000 births respectively. The difference between them is statistically significant (P < 0.05). The distribution of affected area between male and female was not significantly different (chi2 = 1.74, P < 0.05). CONCLUSION: There was no increasing or decreasing trend on the prevalence of congenital clubfoot to be found in China during 2001 to 2010. The prevalence of congenital clubfoot in China was found with regional differences and gender differences. The prevalence of congenital clubfoot in Chinese population is greater than foreign populations.

[Mortality from congenital malformations in children under 5 years old in China, 1996-2006].

OBJECTIVE: To identify the trend and pattern of mortality from congenital malformations in children under 5 years old in China. METHODS: Data from 1996 to 2006 were obtained from the national child mortality surveillance network, which included 116 counties (cities) throughout China. A descriptive analysis was performed on birth defect-specific mortality (U5MR) in children under 5 years old. RESULTS: The national birth defect-specific U5MR decreased from 412.0 per 100,000 live births in 1996 to 342.2 per 100,000 live births in 2006. The declining trend in birth defect-specific U5MR was more obvious from 2003 to 2006. The same pattern was observed in urban areas, in coastal regions and in inner land regions of China. Rural areas had higher birth defect-specific U5MR than urban areas. Remote regions had higher birth defect-specific U5MR than coastal regions and inner land regions. The proportion of mortality due to congenital malformations in total U5MR increased from 9.2% in 1996 to 14.4% in 2006. CONCLUSION: The proportion of mortality due to congenital malformations in children under 5 years old is increasing in China.

[The trend of national advanced maternal age woman proportion in hospital-based surveillance].

OBJECTIVE: To investigate the secular trend of advanced maternal age woman (>or= 35 year-old) in our country. METHODS: Data on maternal woman at different age were collected at surveillance hospital in Chinese Birth Defects Monitoring Network from 1996 to 2007 and retrospective analysis of the trend of advanced maternal women were carried out. Trend analysis of the advanced maternal age in urban and rural areas of west, middle and east areas was also conducted. Chi-square test was applied to test the differences and the fitting model analysis was also applied. RESULTS: A total of 6,308,594 parturient woman were monitored, included 354,511 woman (5.62%) of advanced maternal age. In 1996 and 2007, the proportion of the advanced maternal woman were 2.96% (12,508/422,486) and 8.56% (66,351/775,333), respectively. It showed an increasing trend for the national woman proportion of advanced maternal age from 1996 to 2007 (chi(2) = 45 376.16, P < 0.01). In city, the proportion of advanced maternal age woman were 2.95% (8755/296,975) and 7.69% (40,197/522,596) in 1996 and 2007, respectively. In rural region, the proportion of advanced maternal age woman were 2.99% (3753/125,511) and 10.35% (26,154/252,737) in 1996 and 2007, respectively. It showed increasing both in city and rural areas (chi(2)(city) = 24,152.86, P < 0.01; chi(2)(rural) = 20,809.79, P < 0.01). And the proportions in urban area and rural area were 5.13% (221,655/4,317,533) and 6.67% (132,856/1,991,061), the proportions difference was significant in statistics (chi(2) = 1536.260, P < 0.01). An Exponential model was established, ln(Y) = ln(2.52) + (0.103 x t). In east areas, the proportion were 3.90%and 8.81% in 1996 and 2007, respectively, in middle areas the respective proportions were 2.49% and 8.56%, in west areas were 2.11% and 8.21%. They all showed increasing trend in proportion of advanced maternal age from 1996 to 2007 year in east areas, middle areas and west areas (chi(2)(east) = 11,746.87, P < 0.01; chi(2)(middle) = 17,350.21, P < 0.01; chi(2)(west) = 16,432.68, P < 0.01). But the proportions of city and rural were different in those areas. CONCLUSION: The proportion of advanced maternal woman had secular increasing trend and the rates were lower in city than in rural areas.

[An epidemiological study on conjoined twins in China, from 1996 to 2004].

OBJECTIVE: To understand the trend of incidence of conjoined twins and its epidemiological characteristics in China during 1996 to 2004. METHODS: A descriptive epidemiology of conjoined twinning in China from 1996 to 2004 was investigated by using data from National Center for Birth Defects Monitoring Program (NCBDMP). Data were collected from more than 400 hospital-based units involved in the program. The monitored subjects were the hospitalized births from 28 weeks gestation to a period within 7 days after delivery. RESULTS: 122 conjoined twins were found in 4,282,536 births with an incidence rate of 0. 28 per 10,000. Incidence of conjoined twins was 0.20 per 10,000 and 0.47 per 10,000 in the rural and urban areas, respectively, and the statistical significant difference (P < 0.05) was observed., Incidence of conjoined twins was for 0.17 per 10,000 and 0.36 per 10,000 in boys and girls, respectively. Conjoined twins were more common among females than males, the live-born rate was 41.32%, and the perinatal mortality was 82.6%. 53.7% conjoined twins can be diagnosed prenatally. CONCLUSION: The results indicate that the incidence of conjoined twins in China is higher than that in Western countries. It is necessary to improve the prenatal diagnostic techniques and management.

[Prevalence analysis on congenital hydrocephalus in Chinese perinatal from 1996 to 2004].

OBJECTIVE: To study the epidemiological characteristics of congenital hydrocephalus in Chinese perinatal. METHODS: From 1996 to 2004, data gained from Chinese Birth Defects Monitoring Network were used to depict the epidemiology of congenital hydrocephalus in China. All perinatal born in hospitals had an access within 7 days after delivery. The affected cases were divided into two groups-isolated and syndromic hydrocephalus. And prevalence rates were calculated by year, by sex, by birth area (urban versus rural), by maternal age group and by geographic area (north versus south). Of the affected, fetal age at birth, birth weight, perinatal outcome and prenatal diagnosis were analysed. RESULTS: All 3012 perinatal with congenital hydrocephalus were identified among 4,282,536 births, then an overall prevalence rate was 7.03/10,000, rates of isolated and syndromic hydrocephalus were 5.67/10,000 and 1.36/10,000 respectively. Furthermore, the annual prevalence rates of hydrocephalus presented an increasing trend during that period. The rates in male and female births, in urban and rural area, were 7.09/10,000 and 6.76/10,000, 5.49/10,000 and 10.10/10,000 respectively. There were significant differences among maternal-age-specific prevalence rates, the highest (11.42/10,000) was in an age < 20 years group. For total and isolated hydrocephalus, higher rates were found in north part of China. On the contrary, a higher rate of syndromic hydrocephalus was observed in south part of China. Among the infants with hydrocephalus, the ratio of preterm delivery and of low birth weight were 57.97% and 50.92% respectively. The ratio of congenital hydrocephalus diagnosed antenatally, which could be an indicator representing the capability of detecting the malformation both prenatally and postnatally, showed an upward trend similar to the prevalence rates. The perinatal fatality rates of the total, isolated and syndromic hydrocephalus were 87.75%, 88.66% and 83.91% correspondingly. CONCLUSION: Based on comparison between prevalence rates in China and those reported in foreign countries, our country might be listed into a higher epidemic region of the congenital hydrocephalus. Significant differences were identified between rural and urban areas, between north and south parts of China. The improvement ability in prenatal and postnatal diagnosis should be partly accounted for the increasing prevalence rates of hydrocephalus in Chinese perinatal. The poor birth quality of the affected predicts poor prognosis.

[An epidemiological investigation on gastroschisis in China during 1996 to 2000].

OBJECTIVE: To study the epidemiological characteristics of gastroschisis in China from 1996 to 2000. METHODS: The birth defects monitoring program was undertaken in 450-466 hospitals from 31 provinces, cities and autonomous regions of China. Data about births including intrauterine death and stillbirth of 28 weeks of gestation was collected to report through the medical records over the time period 1996 to 2000. The maximal diagnosis time was up to 1 week after the delivery. The international Classification of Diseases of Ninth Revision with some modifications was used to code the birth defects. RESULTS: A total of 569 cases with gastroschisis was found in 2,218,616 births monitored. The overall birth incidence of gastroschisis was 2.56 per 10,000 births during the monitored period. The increasing trend of incidence of gastroschisis hadn't been found (P > 0.05). The birth incidence of gastroschisis in rural areas was significant higher than that in urban areas (3.93 vs.1.98 per 10,000, P < 0.01). There was also significantly difference on birth incidence between female and male (2.64 vs. 2.15 per 10,000 births, P < 0.05). The birth incidence of gastroschisis in the mothers less than 20 years old was the highest among all mothers age, which were at 5.4 times increased risk relative to that of mother age of 25-29 years old. The overall perinatal mortality rate of gastroschisis was 74.69 percent, and 41.46 percent of gastroschisis were diagnosed before birth. 27.44 percent of cases were accompanied with other major defects. CONCLUSIONS: There was no increasing trend on the incidence of gastroschisis to be found in China during 1996 to 2000. The mother age less than 20 years old was at an increasing risk of fetal gastroschisis. The cases with gastroschisis had a high perinatal mortality rate.

[Analysis of under 5 years old children mortality and the leading death cause in China from 1996 to 2000].

OBJECTIVE: To study the trend of under 5 years old children mortality and the leading cause of the deaths in China from 1996 to 2000. METHODS: The data presented in this report were obtained from the national child mortality surveillance network, including 116 counties (cities) throughout China. The target population was all children under 5 years old in the monitored areas whose mothers or fathers had resided in the area for at least one year. The data were collected and reported by health workers at the three-level network. RESULTS: The neonatal mortality rate (NMR), infant mortality rate (IMR) and under 5 years old mortality rate (U(5)MR) in China dropped to 22.8, 32.2, 39.7 per 1,000 live births in 2000, respectively (they were 24.0, 36.0, 45.0 respectively in 1996), which declined 5.0%, 10.6%, 11.8% from 1996 to 2000, respectively. In urban areas, NMR, IMR and U(5)MR dropped to 9.5, 11.8, 13.8 per 1,000 live births in 2000, respectively (they were 12.2, 14.8, 16.9 respectively in 1996), which declined 22.1%, 20.3%, 18.3% from 1996 to 2000, respectively. In rural areas, NMR, IMR and U(5)MR dropped to 25.8, 37.0, 45.7 per 1,000 live births in 2000, respectively (they were 26.7, 40.9, 51.4 respectively in 1996), which declined 3.4%, 9.5%, 11.1% from 1996 to 2000, respectively. There was a steady decline in the U(5)MR due to diarrhea, pneumonia, neural tube defects and drowning in China. CONCLUSION: In urban/rural areas, the overall decline in NMR, IMR and U(5)MR from 1996 to 2000 was spectacular. Especially the U(5)MR due to avoidable deaths such as pneumonia and diarrhea was dropped markedly in rural areas.

[Epidemiological analysis of syndactyly in Chinese perinatals].

OBJECTIVE: To study the epidemiological features of syndactyly (SD) in Chinese perinatals. METHODS: Data were collected through Chinese Birth Defects Monitoring Network, a hospital-based congenital malformation registry system. From 1987 through 2001 (except 1994, 1995), all live or still births with 28 weeks of gestation or more born in participating hospitals were assessed within 7 days after delivery. RESULTS: Totally 2311 perinatals with SD were identified among 7 478 746 births, and 57.2% of them were in association with other anomalies. The overall prevalence rate of SD was 3.09/10 000, the rate of isolated SD and associated SD was 1.32/10 000, and 1.77/10 000 respectively. The prevalence rates in urban and rural areas, in male and female births were 3.22/10 000 and 2.79/10 000, 3.42/10 000 and 2.59/10 000 respectively. An increasing trend was found during that period. The perinatal fatality rate of SD was 20.7%, that of isolated form was 5.7%, while that of associated form was 31.9%. The proportion of SD occurring in right side was the same as that in left side, and the proportion of SD in upper limbs equaled to that in lower limbs. CONCLUSIONS: The prevalence rate of SD in Chinese perinatals was similar to that reported in foreign literatures. Associated form of SD was more frequently seen. The prevalence of SD in urban areas was higher than in rural areas. Male excess was identified in both isolated and associated forms of SD. No selective predominance was observed either by affected side or by affected limbs.

[Clinical features of 3798 perinatals suffering from syndromic neural tube defects].

OBJECTIVE: To investigate the patterns and associated malformations in neural tube defects (NTDs) cases. METHODS: From 1987 to 1995, hospital-based cluster sampling method was adopted for collecting data. During that period all live or still births with 28 weeks of gestation or more were assessed within 7 days after delivery. RESULTS: Three thousand seven hundred and ninety eight syndromic NTDs were identified, among which anencephaly, spina bifida and encephalocele were 997, 2394 and 407 respectively. 51.3% associated abnormalities of NTDs appeared in muscle and skeletal system, 19.6% in face, ear and neck, and 9.3% in urinary-genital system. Congenital talipes equinovarus, cleft lip with cleft palate, gastroschisis, talipes valgus, undescended testicle were frequently combined with NTDs. The most frequent association in schisis type of NTDs was NTDs accompanied by cleft lip with or without cleft palate (67.5%), followed by anencephaly with cleft palate (8.3%) and anencephaly with omphalocele (6.6%). Of all syndromic NTDs, the rate of low birth weight was 36.9%, of perinatal mortality was 71.2% and the ratio 33.1% patients were diagnosed prenatally. CONCLUSIONS: Approximately one third of NTDs may be associated with other system's malformation. Syndromic NTDs has a high perinatal mortality rate and a poor prognosis.

[Analysis of maternal mortality in China from 1996 to 2000].

OBJECTIVE: To study the trend and characteristics of maternal mortality in China from 1996 to 2000. METHODS: Population-based epidemiological survey in 116 monitoring units in China were used. RESULTS: Maternal mortality in China dropped by 17.1% from 63.9 per 100,000 live births in 1996 to 53.0 in 2000, in rural area dropped by 22.2% from 86.4 per 100,000 live births to 67.2, and in urban area only 1.0% from 29.2 per 100 000 live births to 28.9, the leading causes of maternal mortality in China are hemorrhage, preeolampsia/eclampsia and amniotic fluid embolism the maternal mortality due to hemorrhage in national level and rural level has declined by 33.8%, 34.9% respectively. CONCLUSION: The maternal mortality appears a declined trend on both the national and rural levels in China from 1996 to 2000, the maternal mortality due to hemorrhage dose also, bur the maternal mortality in urban area keeps unstable.

[An epidemiological study on omphalocele in China during 1996 to 2000].

OBJECTIVE: To understand the trend of incidence of omphalocele and its epidemiological characteristics in China during 1996 to 2000. METHODS: Surveillance data of omphalocele were collected from 460 hospitals at county level or above county level, involving all births with 28-week gestation to 7 days after delivery, including live births, fetal deaths and stillbirths in 31 provinces, autonomous regions and municipalities all over the country during 1996 to 2000. RESULTS: Overall incidence of omphalocele in China was 1.52 per 10 000 live births, with an increasing trend during 1996 to 2000. Incidence of omphalocele was 1.40 per 10 000 and 1.83 per 10 000 in the rural and urban areas, respectively, with a statistically significant difference (P < 0.05), and 1.54 per 10 000 and 1.41 per 10 000 in boys and girls, respectively. Babies of omphalocele associated with other malformation accounted for 30.77% of the total cases. Perinatal fatality rate of omphalocele was 51.18%, with prenatal diagnostic rate of 31.07%. CONCLUSIONS: Prevalence of omphalocele appeared an increasing trend in China during the period from 1996 to 2000. Occurrence of omphalocele was more frequent in rural areas than that in urban areas. Perinatal fatality rate in babies with omphalocele was higher and fatality of associated omphalocele was higher than that of simple one. It is suggested that management of perinatal care and level of prenatal diagnosis for omphalocele should be improved.

[Maternal mortality in rural areas of China].

OBJECTIVE: To understand with clearness the trend and epidemiological characteristics of maternal mortality, as well as the leading causes of maternal deaths in rural areas of China from 1996 to 2001. METHODS: The data analyzed were those from the population-based epidemiological survey conducted by the national maternal mortality surveillance network which covered a total population of about 35,000,000 in China. RESULTS: The maternal mortality ratio (MMR) in rural areas of China dropped by 28.4% from 86.4 per 100,000 live births in 1996 to 61.9 in 2001. The leading causes of maternal deaths were obstetric hemorrhage, preeclampsia and embolism of amniotic fluid. The MMR for obstetric hemorrhage decreased from 48.3 per 100,000 live births in 1996 to 33.0 in 2001. The pregnant women mainly gave childbirths and died in their home, accounting for 44.6% and 30.1% respectively in 2001. CONCLUSION: The MMR showed a downward trend in rural areas of China during the period from 1996 to 2000, and so also did the MMR for obstetric hemorrhage. Reducing obstetric hemorrhage and increasing the rate of hospitalized delivery are the most important methods for reducing the MMR in rural areas in China.

[Epidemiological analysis of polydactylies in Chinese perinatals].

OBJECTIVE: To investigate the epidemiologyical characteristics of polydactyly. METHODS: The method of Hospital-based surveillance within Chinese Birth Defects Monitoring Network (CBDMN) was adopted. All perinatals (from 28 weeks of gestation to a period of 7 days after birth) in the participating hospitals were investigated from 1996 to 2000. RESULTS: A total of 2097 cases were identified in 2218616 perinates, the prevalence was 9.45 per 10000. The prevalence of male was significantly higher than the female's. The urban prevalence was 9.60 per 10000, and the rural prevalence was 9.05 per 10000. Significant difference and increasing time trend were observed in annual prevalence rate during 1996-2000. Of the 2097 cases, 1853 (88.4%) were in the isolated form, and the rest (11.6%) of them were combined with other defects. Among 1942 perinatals affected by polydactyly, 679 (34.96%) cases occurred in the left limbs, 886 (45.62%) cases occurred in the right limbs, and 377 (19.41%) cases occurred bilaterally. CONCLUSION: The prevalence rates of polydactylies in Chinese perinatals show male predominance and geographic variations. Most of the polydactyly cases were in the from of single defect; however, those accompanied by other defects had a higher perinatal fatality rate.

[Incidence and its trends on gastroschisis in some parts of China, 1996 - 2007].

OBJECTIVE: To investigate the incidence and its secular trends of gastroschisis in Chinese perinatal infants. METHODS: Data on perinatal infants was collected at hospitals under surveillance program in Chinese Birth Defects Monitoring Network from 1996 to 2007. Data on incidence, trend and related factors of gastroschisis in perinatal infants were carried out. Both χ(2) test and Poisson regression model were used to test the differences between residential areas, sex and maternal age. Both χ(2) trends test and Poisson regression model were applied to analyze the trends. RESULTS: A total of 6 308 594 perinatal infants were monitored during 1996 - 2007, including 1601 infants with gastroschisis to show the incidence as 2.54 per 10 000 births. The overall prevalence of gastroschisis in China did not change remarkably during the period of our research. The incidence rates of gastroschisis were significantly different between urban and rural areas, between different sex and different maternal age groups. The incidence of gastroschisis was lower in urban area than in rural area (RR = 0.58) and lower in female fetuses than in male fetuses (RR = 0.76), highest in the group younger than 20 years of age, which was 11.43 times than incidence of the 30 - 34 age group (RR = 11.432). CONCLUSION: The overall prevalence of gastroschisis in China did not show remarkable change during 1996 - 2007 but the incidence of gastroschisis a bit increased in the area of study and significant differences were seen in different sex, regions and maternal age groups. Mothers aged younger than 20 years old appeared to be a significant risk factor for the occurrence of gastroschisis.

[Analysis on the diarrhea mortality rate, pre-death diagnosis and treatment of children under-5 in China, 1996-2006].

OBJECTIVE: To understand the trends of diarrhea mortality rate, pre-death diagnosis and treatment of children under-5 in China, from 1996 to 2006. METHODS: We used data obtained from the 1996 to 2006 national child mortality surveillance network, including 116 counties (cities) throughout China, to evaluate the under 5 mortality rate (U5MR) due to diarrhea in different geographical areas, and related factors of under 5 children mortality due to diarrhea. RESULTS: Data from the national U5MR due to diarrhea fell from 249.8 in 1996 to 75.6 per 100 000 live births, in 2006. The U5MR due to diarrhea in urban reduces from 11.6 in 1996 to 6.1 per 100 000 live births in 2006, with a reduction of 47.4%. The U5MR due to diarrhea in rural decreased from 304.7 in 1996 to 94.3 per 100 000 live births in 2006, with a reduction of 69.1%. The U5MR due to diarrhea in coastal, inland and remote areas fell from 48.9, 178.9 and 566.9 in 1996 to 6.2, 30.4 and 199.2 per 100 000 live births in 2006, with a reduction of 87.3%, 83.0% and 64.9%, respectively. Among the rural children died of diarrhea, about 37.9% were diagnosed in a village clinic, 15.1% never received any diagnostic procedure. Nearly 20% of the patients had not been treated, with 50% - 60% of them had only been treated in an outpatient department. CONCLUSION: During 1996 - 2006, the U5MR due to diarrhea showed a substantially downward trend in China but the disparities between urban and rural, remote and coastal, areas were increasing.

Spatial distribution patterns of anorectal atresia/stenosis in China: use of two-dimensional graph-theoretical clustering.

AIM: To investigate the spatial distribution patterns of anorectal atresia/stenosis in China. METHODS: Data were collected from the Chinese Birth Defects Monitoring Network (CBDMN), a hospital-based congenital malformations registry system. All fetuses more than 28 wk of gestation and neonates up to 7 d of age in hospitals within the monitoring sites of the CBDMN were monitored from 2001 to 2005. Two-dimensional graph-theoretical clustering was used to divide monitoring sites of the CBDMN into different clusters according to the average incidences of anorectal atresia/stenosis in the different monitoring sites. RESULTS: The overall average incidence of anorectal atresia/stenosis in China was 3.17 per 10,000 from 2001 to 2005. The areas with the highest average incidences of anorectal atresia/stenosis were almost always focused in Eastern China. The monitoring sites were grouped into 6 clusters of areas. Cluster 1 comprised the monitoring sites in Heilongjiang Province, Jilin Province, and Liaoning Province; Cluster 2 was composed of those in Fujian Province, Guangdong Province, Hainan Province, Guangxi Zhuang Autonomous Region, south Hunan Province, and south Jiangxi Province; Cluster 3 consisted of those in Beijing Municipal City, Tianjin Municipal City, Hebei Province, Shandong Province, north Jiangsu Province, and north Anhui Province; Cluster 4 was made up of those in Zhejiang Province, Shanghai Municipal City, south Anhui Province, south Jiangsu Province, north Hunan Province, north Jiangxi Province, Hubei Province, Henan Province, Shanxi Province and Inner Mongolia Autonomous Region; Cluster 5 consisted of those in Ningxia Hui Autonomous Region, Gansu Province and Qinghai Province; and Cluster 6 included those in Shaanxi Province, Sichuan Province, Chongqing Municipal City, Yunnan Province, Guizhou Province, Xinjiang Uygur Autonomous Province and Tibet Autonomous Region. CONCLUSION: The findings in this research allow the display of the spatial distribution patterns of anorectal atresia/stenosis in China. These will have important guiding significance for further analysis of relevant environmental factors regarding anorectal atresia/stenosis and for achieving regional monitoring for anorectal atresia/stenosis.

[Using two-dimensional graphic cluster method to study the geographic distribution pattern of patients with anorectal atresia/stenosis, in China].

OBJECTIVE: To investigate the geographic distribution pattern of patients with anorectal atresia/stenosis in China, in order to provide clue for research on its etiology. METHODS: Data were collected from Chinese Birth Defects Monitoring Network (CBDMN), which was a hospital-based congenital malformations registry system. From 2001 to 2005, all fetuses with more than 28 weeks of gestation and neonates up to 7 days of age, were monitored. Two-dimensional graphic cluster method was used to divide monitoring stations into different classes with the incidence rates of anorectal atresia/stenosis. RESULTS: The overall incidence of anorectal atresia/stenosis was 3.17 per 10,000 during 2001 to 2005. The incidence was higher in Eastern than that in Mid or Western parts of China and the difference was statistically significant (z = 2.50, 3.69; P = 0.012, < 0.001). The monitoring stations were grouped into 6 classes. Class I was with Heilongjiang, Jilin and Liaoling; Class II was with Fujian, Guangdong, Hainan, Guangxi, and South Hunan and Jiangxi; Class III was with Beijing, Tianjin, Hebei, Shandong, and North Jiangsu and Anhui; Class IV was with Zhejiang, Shanghai, South Anhui and Jiangsu, North Hunan and Jiangxi, Hubei, Henan, Shanxi and Inner Mongolia, Class V was with Ningxia, Gansu and Qinghai; and Class VI was with Shaanxi, Sichuan, Chongqing, Yunnan, Guizhou, Xinjiang and Tibet. CONCLUSION: Our findings discovered the geographic distribution patterns of patients with anorectal atresia/stenosis in China. It is important to further analyze the relevant environmental factors attached to it so a better regional monitoring system for anorectal atresia/stenosis can be operated.

[The prevalence analysis of cleft palate in Chinese perinatals: 1996-2000].

OBJECTIVE: To study the epidemiological features of cleft palate (CP) in Chinese perinatals. METHODS: Data from 1996 to 2000 were collected through Chinese Birth Defects Monitoring Network a hospital based congenital malformation registry system. During that period all live or still births with 28 weeks of gestation or more were assessed within 7 days after delivery. RESULTS: 499 perinatals with CP were identified among 2,218,616 births, then the overall prevalence rates of CP were 2.25/10,000, rates in isolated and syndromic CP were 1.75/10,000, 0.50/10,000 respectively. The rates in urban and rural area, in male and female births were 2.27/10,000 and 2.19/10,000, 1.93/10,000 and 2.57/10,000 respectively. The highest but nonsignificant rate (2.84/10,000) was found in maternal age group of more than 35 years. An increased trend was found both in overall CP and syndromic CP during that period. Geographic variation was found among provinces. The perinatal mortality rate of CP was 14.9%, and the rate of isolated forms was 7.3%, while the rate of syndromic CP was as high as 41.4%. CONCLUSION: The increasing prevalence rate of syndromic CP can account for the secular trend of overall CP. Female predominance was only observed in isolated forms of CP among Chinese perinatals. Geographic variation was identified too. Due to poor birth quality, perinatals suffering from syndromic CP had poor prognosis.

[The monitoring of cleft lip with or without cleft palate in China: 1996 - 2000].

OBJECTIVE: To describe the epidemiological features of cleft lip with or without cleft palate (CL +/- P) in Chinese perinatals. METHODS: From 1996 through 2000, hospital-based cluster sampling method was adopted for collecting data. During that period all live or still births with 28 weeks of gestation or more delivered in monitoring hospitals were assessed within 7 days after birth. RESULTS: The birth prevalence rates of cleft lip (CL) and of cleft lip with cleft palate (CLP) were 5.03/10,000, 8.97/10,000 respectively, then the rate of CL +/- P was 14.0/10,000. The prevalence rates in urban and rural area, in male and female births were 13.28/10,000 and 15.57/10,000, 16.06/10,000 and 11.40/10,000 respectively. Significant difference was found among maternal-age-specific prevalence rates, and the highest one was observed in >or= 35 maternal age group. 87.25% of CL +/- P was isolated forms. No secular trend was found during that period. The perinatal fatality rate of CL +/- P was 19.04%, and the rate in isolated forms was 12.69%, but the rate in syndromic CL +/- P was as high as 62.60%. CONCLUSIONS: No decline trend in prevalence rate of CL +/- P was observed during 1996 approximately 2000. Compared with prevalence rates of CL +/- P in some foreign countries, it was higher in China during same period.

[Epidemiological investigation of perinatals affected by transverse facial cleft in China].

OBJECTIVE: To study the epidemiological features of transverse cleft and its multiple congenital anomaly (MCA) patterns in China. METHODS: From 1987 through 1992, hospital-based cluster sampling method was adopted for collecting data. During that period all live or stillbirths with 28 weeks of gestation or more were assessed within 7 days after delivery. RESULTS: 94 cases of transverse facial cleft were identified among 4,489,692 births, so the prevalence rate of transverse facial cleft at birth was 0.21/10(4). The prevalence rates in urban areas and in rural areas were 0.20/10(4) and 0.23/10(4), respectively. And the rates in male and female births were both 0.21/10(4). 69 cases occurred with other malformations, among which the anomalies of ear were the most frequent association (53.6%). The perinatal fatality rate was 46.9%, a significant difference of fatality rate was found between isolated forms (16.0%) and associated forms of transverse facial cleft (58.0%). CONCLUSIONS: The prevalence rate of transverse facial cleft in China is more than the estimated rate. No significant differences are found between urban and rural areas, and between male and female births. Most of transverse facial clefts are associated forms, often as one feature of other syndromes.