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Objective To predict the incidence of birth defects in Xi'an using the auto-regressive integrated moving average product seasonal model.Methods In Xi'an,the trend of the incidence of birth defects was analyzed and tested from October 2009 to August 2015.Using the data from September to December 2015,the actual birth defects were compared with the model fitting data to evaluate the predictive performance of the model.Multiple seasonal ARIMA model was then fitted under time series to predict the incidence of birth defects in 2016.Results Seasonal effect was seen in the incidence of birth defects in Xi'an.A multiple seasonal ARIMA(0,0,1) (0,1,1)12 was established.The mean of absolute error and the relative error were 9.5 and 0.084,respectively,when compared to the simulated number of patients from September to December in 2015,suggesting that ARIMA (0,0,1) (0,1,1)12 has a better predictive ability.Results under the prediction of multiple seasonal ARIMA model showed that the number of patients in 2016 was similar to that of 2015 in Xi'an,with a slight increase and a decrease in the peak value.Conclusion Multiple seasonal ARIMA(0,0,1)(0,1,1)12 model could be used to successfully predict the incidence of birth defects in Xi'an.
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Objective To investigate the dynamic epidemiological characteristics of perinatal birth defects in Xi'an so as to provide scientific evidence for the priority of future birth defect prevention.Methods We made a statistical description of the data of perinatal birth defects from 2010 to 2015 reported by all the maternity hospitals in Xi'an.Results The incidence of birth defects in Xi'an from 2010 to 2015 was 89.62/104 (87.60/104,91.74/ 104) and had an annual ascending tendency (x2-157.13,P＜0.01).The top five main birth defects in a descending order were congenital heart disease (26.53/104),polydactyly (13.10/104),total cleft lip (11.42/104),neural tube defects (6.06 /104),and congenital hydrocephalus (5.08/104),accounting for 69.39％ of the total number of birth defects.And the incidence of congenital heart diseases showed a year-by-year ascending trend (x2=837.65,P＜ 0.01).The incidence of birth defects was higher in urban areas than in rural areas (OR 1.108,95％ CI:1.056-1.162).The birth defects were more frequently seen in males than in females (OB=1.151,95％ CI:1.097-1.208).Mother's age ＜20 (OR=1.764,95％ CI..1.532-2.032) and mother'sage≥35 (OR=1.283,95％ CI:1.179-1.395) also were risk factors for birth defects.Up to 72.54％ of the defects were live births.There were 52.83％ cases diagnosed by ultrasound and 46.24％ ones by clinical examination.The prenatal diagnosis rate was 33.20％.Conclusion The incidence of perinatal birth defects in Xi'an from 2010 to 2015 showed an annual ascending trend.We should improve the prenatal diagnosis level of all monitored hospitals in order to reduce incidence of birth defects and increase the quality of population.
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Objective To study the effects of air pollution including sulphur dioxide (SO2),nitrogen dioxide (NO2) and PM10 in Xi'an on birth defects.Methods We collected the birth defects data from Xi'an Maternal and Child Health Hospital,meteorological data from Xi'an Bureau of Meteorology,and the air pollution data from Xi'an Environment Monitoring Station from 2010 to 2015.Generalized additive model (GAM) was used to explore the relationship between air pollution and birth defects after adjusting the effects of long-term and seasonal trend,temperature,and relative humidity.Results The monthly average birth defects were 89 cases;the monthly average concentration of SO2,NO2 and PM10 was 34.05 μg/m3,45.13 μg/m3,and 96.77 μg/m3,respectively.In the GAM,the monthly average temperature was 13.57 ℃ and the relative humidity was 63.20％.The three kinds of air pollutants all had a certain lag effect in 10 months,which reached the maximum.With an increase of concentration by 10 μg/m3 in three air pollutants,the relative risks and confidence interval of SO2,NO2,and PM10 were 1.060 (1.023-1.097),1.033 (1.014-1.052) and 1.018 (1.007-1.029),with significant differences (P＜0.05).Conclusion Exposure to SO2,NO2,and PM10 may be associated with the risk of birth defects.
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Objective To analyze the spatial distribution characteristics of birth defects and air pollution in Xi'an and the correlation between air pollution exposure and birth defects.Methods In this study,we calculated the mean and median concentration of air pollutants in Xi'an between 2010 and 2015 to describe their concentration trends.Then we analyzed quartile range to describe their discrete trend.The spatial distribution of air pollution in the whole study area was calculated by inverse distance weighted spatial interpolation method to describe its overall occurrence level.The global trend was analyzed to describe the main body change pattern in the birth defect space.The total number of birth defects in the districts and counties of Xi'an between 2010 and 2015 was calculated and the incidence of birth defects was calculated according to the monitoring data of live births.Correlation between birth defects and air pollution was analyzed by rank correlation analysis.Results The spatial distribution of air pollutants in Xi'an between 2010 and 2015 was as follows:the concentration of SO2 was relatively high in Lianhu District,Yanta District,Baqiao District,Beilin District,and Xincheng District.The concentration of NO2 was relatively high in Yanta District,Baqiao District,Lianhu District,Beilin District,and Xincheng District.The concentration of PM10 was relatively high in Baqiao District,Yanta District,Xincheng District,Weiyang District,and Yanliang District.In Baqiao District,Xincheng District,Lianhu District,Weiyang District,and Gaoling District,the concentration of PM2.5 was relatively high.The total number of birth defects was 6 858 cases in Xi'an between 2010 and 2015,and the total number of perinatal births was 752 142 cases,with the incidence of 91.18 (1/10 000).The spatial distribution of birth defects from the west to the east direction and from south to north direction was generally characterized of inverted U type.The birth defects were positively correlated with NO2 concentration.Conclusion There are obvious regional differences in air pollution and birth defects in Xi'an.Birth defects may be related to NO2.
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Objective To analyze the trend of birth defects and air pollution in Xi'an and discuss the correlation between air pollution exposure and birth defects.Methods Time series multiplication model was used to decompose the time series of birth defects and concentration of air pollutants to describe their long-term trend and seasonal variations.The rank correlation and cross-correlation between birth defects and air pollutants were analyzed by ecological approach.Results During 2010-2015,the results of air pollution analysis in Xi'an showed that the overall trend of NO2 increased in 2013 and then fluctuated at a high level.Generally,SO2 showed a trend of slow decline,but there were two peaks in 2012 and 2013.The overall trend of PM10 had two small peaks in 2013 and 2014,and during the rest of the time the change was stable.The overall trend of PM2.5 showed a slow decline,but after 2015 it showed a slight increase.Analysis of the birth defects during 2010-2015 in Xi'an showed that the long-term trend of total birth defects and congenital heart disease increased in 2010-2014,but then decreased rapidly.The long-term trend of cleft lip and palate and neural tube defects fluctuated at a low level.Analysis of the correlation between air pollutants and birth defects showed that total birth defects and congenital heart disease were positively correlated with NO2 at 3 months before pregnancy and early 3 months of pregnancy.Congenital heart disease 3 months before pregnancy had a positive correlation with PM10.Conclusion Birth defects and air pollution in Xi'an have trend variations and seasonal regularity.There is a positive correlation of women's exposure to NO2 3 months before pregnancy and the first 3 months of pregnancy with the incidence of congenital heart disease.
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Objective To understand the levels of exposure to traffic-related air pollutants including nitrogen dioxide (NO2),PM10 and PM2.5,and the relationship between the exposure to air pollutants during pre-pregnancy or early pregnancy and birth defects.Methods Data on air pollution and birth defects from 2013 to 2015 was collected.A case-crossover design was employed to analyze the exposure-response relationship between traffic-related air pollutants and birth defects.Results A total of 4 235 pregnant women were studied.During the study period,the daily average concentrations of ambient NO2,PM10 and PM25 appeared as 60.83 μg/m3,104.94 μg/m3 and 103.88 μ.tg/m3,respectively,with the concentration of PM2.5 larger than the 2nd version of Standard National Ambient Air Quality Standard.In addition,there were strong correlations seen between each of the pollutants (P＜0.01).After adjustment for the influence of meteorological factors,it was found that the exposure to high level of NO2 and PM10 during pre-pregnancy or early pregnancy increased the risk on birth defects (P＜0.05).Conclusion Levels of exposure to adverse environmental factors during pre-pregnancy or early pregnancy could increase the risk of birth defects,suggesting that in these sensitive periods,women should try to avoid being exposed to high concentration of traffic-related air pollutants as NO2,PM10 etc.in order to reduce the risk of birth defects.
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Objective To understand the levels of exposure to traffic-related air pollutants including nitrogen dioxide (NO2),PM10 and PM2.5,and the relationship between the exposure to air pollutants during pre-pregnancy or early pregnancy and birth defects.Methods Data on air pollution and birth defects from 2013 to 2015 was collected.A case-crossover design was employed to analyze the exposure-response relationship between traffic-related air pollutants and birth defects.Results A total of 4 235 pregnant women were studied.During the study period,the daily average concentrations of ambient NO2,PM10 and PM25 appeared as 60.83 μg/m3,104.94 μg/m3 and 103.88 μ.tg/m3,respectively,with the concentration of PM2.5 larger than the 2nd version of Standard National Ambient Air Quality Standard.In addition,there were strong correlations seen between each of the pollutants (P＜0.01).After adjustment for the influence of meteorological factors,it was found that the exposure to high level of NO2 and PM10 during pre-pregnancy or early pregnancy increased the risk on birth defects (P＜0.05).Conclusion Levels of exposure to adverse environmental factors during pre-pregnancy or early pregnancy could increase the risk of birth defects,suggesting that in these sensitive periods,women should try to avoid being exposed to high concentration of traffic-related air pollutants as NO2,PM10 etc.in order to reduce the risk of birth defects.
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<p><b>BACKGROUND</b>To investigate the surveillance trend of birth defects, incidence, distribution, occurrence regularity, and their relevant factors in Xi'an City in the last 10 years for proposing control measures.</p><p><b>METHODS</b>The birth defects monitoring data of infants during perinatal period (28 weeks of gestation to 7 days after birth) were collected from obstetrics departments of all hospitals during 2003-2012. Microsoft Excel 2003 was used for data input, and Statistical Package for the Social Sciences version 16.0 (International Business Machines Corporation, New York, NY, USA) was used for descriptive analysis. χ2 test, Spearman correlation and linear-by-linear association trend test were used for statistical analyses.</p><p><b>RESULTS</b>The birth defect rate declined from 9.18% in 2003 to 7.00% in 2012 (χ2 = 45.001, P < 0.01) with a mean value of 7.85%, which is below the Chinese national average level (χ2 = 20.451, P < 0.01). The order of five most common birth defects has changed. The incidence of congenital heart disease (CHD) increased with time, particularly after 2012, it became the most frequent type (r s = 0.808, P < 0.001). Till then, the number of neural tube defects (NTDs) declined significantly (χ2 = 76.254, P < 0.01). The average birth defects rate of 8.11% in rural areas was higher than that in urban areas (7.56%, χ2 = 7.919, P < 0.01) and much higher in males (8.28%) than that in females (7.18%, χ2 = 32.397, P < 0.01). Maternal age older than 35 years (χ2 = 35.298, P < 0.01) is the most dangerous age bracket of birth defects than maternal age younger than 20 years (χ2 = 7.128, P < 0.01).</p><p><b>CONCLUSIONS</b>A downward trend of birth defects was observed in Xi'an City from 2003 to 2012. NTDs significantly decreased after large-scale supplemental folic acid intervention, while the incidence rate of CHD significantly increased.</p>