[Construction of natural population cohort on telephone follow-up management quality control system and discussion regarding critical issues by REDCap system].

With completing a baseline survey of a large natural population cohort, conducting regular follow-up has become a key factor in further improving the quality of cohort construction and ensuring its sustainable development. Typical cohort follow-up methods include repeat surveys, routine monitoring, and community-oriented surveillance. However, in practical applications, there are often issues such as high costs, difficulty, and high error rates. Telephone follow-up is an important supplementary method to the methods mentioned above, as it has the characteristics of low cost, fast response, and high quality. However, the with difficult organization, quality control is challenging, response rates are low, and management levels vary widely, which limits its widespread use in large-scale population cohort studies. Given the above problems, this study draws on customer relationship management based on the actual needs of the China Northwest Cohort follow-up. It relies on the REDCap electronic data collection platform to build a telephone follow-up management and quality control system. Targeted solutions are provided for key issues in telephone follow-up implementation, including organizational structure, project management, data collection, and process quality control, to improve the quality control level of telephone follow-up comprehensively and thereby enhance the quality and efficiency of follow-up. We hope to provide standardized follow-up programs and efficient quality control tools for newly established and existing cohort studies.

[Association between muscle mass and quality of life in Shaanxi adults].

Objective: To investigate the association between muscle mass and quality of life in adults in Shaanxi adults. Methods: The data in this analysis were part of the baseline survey of the Regional Ethnic Cohort Study in Northwest China from June 2018 to May 2019 in Shaanxi Province. The participants' quality of life, including physical component summary (PCS) and mental component summary (MCS), was assessed by the 12-Item Short Form Survey, and the Body Fat Determination System measured muscle mass. A logistic regression model with adjustment for confounding factors was established to analyze the association between muscle mass and quality of life in different genders. Further, sensitivity and subgroup analyses were conducted to explore its stability. Finally, a restricted cubic spline was employed to investigate the dose-response relationship between muscle mass and quality of life in different genders. Results: A total of 20 595 participants were included, with an average age of 55.0, and 33.4% were male. After controlling for potential confounders, compared with the Q1 group, the risk of low PCS was reduced by 20.6% (OR=0.794, 95%CI: 0.681-0.925) and the risk of low MCS was lower reduced by 20.1% (OR=0.799, 95%CI: 0.689-0.926) in female Q5 groups. Compared with the Q1 group, the risk of low PCS was reduced by 24.4% (OR=0.756, 95%CI: 0.644-0.888) in the male Q2 group. However, no significant association between muscle mass and MCS in males has been found. In females, restricted cubic spline analysis showed a significant linear dose-response relationship between muscle mass and PCS and MCS. Conclusions: There is a positive association between muscle mass and quality of life in Shaanxi adults, especially females. With the increase in muscle mass, the physical and mental functions of the population continue to improve.

[Relationship between Chinese dietary guidelines compliance index for pregnant women and congenital heart disease in offspring].

Objective: To study the relationship between the Chinese dietary guidelines compliance index for pregnant women (CDGCI_PW) and congenital heart disease (CHD) in offspring. Methods: In a hospital-based case-control study conducted in Xi'an, Shaanxi province, semi-quantitative food frequency questionnaires were used to investigate the diets of pregnant women throughout pregnancy. The modified CDGCI_PW score was used to evaluate dietary quality during pregnancy, logistic regression was applied to analyze the relationship between CDGCI_PW score and offspring CHD, and the ROC curve was adopted to construct the prediction model of CDGCI_PW for offspring CHD. Results: A total of 1 422 subjects were enrolled, including 474 in the case group and 948 in the control group. The CDGCI_PW score in the case group M (Q1, Q3) was 46.0 (26.0, 65.0) lower than that in the control group, which was 60.0 (40.0, 77.0). The difference between the two groups was significant (P<0.001). Compared with those in the Q1 of CDGCI_PW, the offspring in the Q2, Q3, and Q4 of CDGCI_PW had a lower risk of total CHD (OR=0.60, 95%CI: 0.43-0.83; OR=0.64, 95%CI: 0.45-0.89; OR=0.29, 95%CI: 0.19-0.44), with the trend test P<0.001. The risk of total CHD was reduced by 17% (OR=0.83, 95%CI: 0.79-0.88) when 10 points increased the CDGCI_PW score. The area under curve predicted by constructing the ROC curve was 0.793 (95%CI: 0.768-0.818), and at the maximum of the Youden index, the sensitivity was 0.740, and the specificity was 0.725. Conclusion: This study suggests that improving dietary quality during pregnancy may reduce the risk of CHD in offspring.

[Application of isotemporal substitution model in epidemiological research].

Isotemporal substitution model is a powerful tool to explore the real association between physical behavior and health outcomes, which has the potential of the application in large-scale cohort study. This paper systematically introduces the principle of isotemporal substitution model and its implementation method in specific analysis to provide analytical ideas for the epidemiological research related to physical behavior in China. The baseline data of Regional Ethic Cohort Study in Northwest China conducted in Shaanxi province were used to analyze the relationship between physical behavior and cardiovascular disease with single-factor model, partition model and isotemporal substitution model. The advantages and disadvantages of different models were compared, and the advantages of isotemporal substitution model in quantifying physical activity health risk were introduced. Isotemporal substitution model could qualify physical behavior and health outcomes, which has wide application value in epidemiological research.

[The association between calcium supplementation in antenatal childbearing aged women and risk of small for gestational age among neonatal singleton in Shaanxi province].

Objective: This study explored the association between antenatal calcium supplementation in the childbearing aged women and risk of small for gestational age infant (SGA) among singleton in Shaanxi province,China. Methods: Multi-stage random cluster sampling method was employed to collect information about pregnant women, who were pregnant and had definite outcomes, and their infants, from 30 districts (counties) in 2010 to 2013. Information was collected by face-to-face questionnaire survey. Generalized linear mixed models were employed after adjusting covariates. Dependent variable was whether single-birth neonate was SGA, and independent variable was calcium supplementation of childbearing aged women in different pregnant periods. Results: A total of 28 357 childbearing aged women was recruited in this study. The age of these women was (28.08±4.74) years old, of which, 79.28% were rural residents and 60.90% had calcium supplementation intake. There was a number of 12 810 female in singleton neonates. The neonatal birth weight and gestational age were (3.27±0.16) kg and (277.44±8.80) day, respectively. The prevalence of SGA was 11.35% in total, and 10.48% in mothers with maternal calcium supplementation and 12.70% in mothers without maternal calcium supplementation in whole antenatal period. There were statistically significant differences seen in antenatal calcium supplementation within the subgroups of maternal age (whether the mother was an advanced maternal woman), residential area, maternal occupation, maternal parity, maternal education level, and household incomes (P<0.05). After adjusting these covariates, the risk of SGA among childbearing aged women with antenatal calcium supplementation showed 16% decreased risk (OR=0.84, 95%CI: 0.77-0.92). Further analysis of the different antenatal periods showed that calcium supplementation during the second and third trimester had a statistically significant difference in reducing the risk of neonatal SGA (P<0.05). Besides, subgroup analysis showed that there was a statistically significant difference between the perinatal calcium supplementation and the single-born neonates with SGA Significance (P<0.05) in non-advanced women, those who had a low education level and moderate household economic status groups. Conclusion: The risk reduction of SGA among singleton neonates is related to calcium supplementation during antenatal period in Shaanxi province.

[Method of double data entry and quality control by REDCap system].

In medical research, the quality of data is the key to success. Thus, data quality control becomes an important part of ensuring the research's high quality. REDCap system is an emerging data acquisition system in medical research, which is gradually applied in research at home and abroad. It is a hot issue to realize double data entry and data quality control in using the REDCap system, which researchers are concerned about when this system is supposed to apply. This article will systematically introduce how to use the REDCap system for double data entry and quality control from the aspects of research project creation, data collection tool design, double data entry, data checking and exporting.

[Association of maternal anxiety with congenital heart disease in offspring based on case-control study].

Objective: To explore the association of maternal anxiety with congenital heart disease (CHD) in offspring. Methods: A case-control study design was used in this study. The data were collected in Shaanxi province from January 2014 to December 2016. Neonatal information is provided through specialized hospitals or institutions. Logistic regression model with adjustment for confounding factors was established to analyze the association between maternal perinatal anxiety and CHD in offspring. Meanwhile, subgroup analysis was carried out to explore its stability. Results: Our study included 2 429 subjects, consisting of 773 cases and 1 656 controls. Women with anxiety during pregnancy accounted for 10.3% in the case group, while 7.8% in the control group. After adjusting for confounding factors, the level of maternal anxiety during pregnancy was positively correlated with CHD in the offspring (OR=1.04, 95%CI: 1.01-1.07). The risk of CHD in the offspring of mothers with anxiety during pregnancy was 1.43 times higher than that in those whose mothers had no anxiety (OR=1.43, 95%CI: 1.00-2.05). Conclusion: Maternal anxiety during pregnancy is probably a risk factor for congenital heart disease in offspring.

[Application of electronic data acquisition system REDCap in large natural population-based cohort studies].

Cohort study is one of the basic methods used in epidemiological research. With the development of the etiological analysis of complex diseases such as cardiovascular diseases, large natural population-based cohort study has become a popular topic in medical research. In the process of cohort development, one of the important issues is to ensure the efficiency and safety on data collection. As a database management system, with open source, free clinical research data collection and high quality, REDCap can widely be applied in large population-based cohort studies. This article summarizes the baseline survey and follow-up procedures on cohort studies and introduces a REDCap-system-based solution for data collection and management. Contents on the establishment of data working groups, data collection, cohort follow-up methods and field application are also discussed in this paper, in order to improve the efficiency of data collection and management in cohort study to help the development of cohort study in China.

[Epidemiological characteristics of serum vitamin B(12) and folate levels in women awaiting delivery].

Objectives: To analyze the epidemiological characteristics and levels of vitamin B(12) and folate as well as their relationship in women awaiting delivery, in Shaanxi province. Methods: Data were collected from healthy pregnant women who gave birth at six top hospitals in Shaanxi, from January 2014 to December 2016. Blood samples were taken prenatally to determine the levels of vitamin B(12) and folate. Quantile regression model was used to analyze the relationship between the levels of vitamin B(12) and folates in women awaiting delivery. Results: A total of 1 277 women awaiting delivery were included in this study. Among them, the median level of serum vitamin B(12) was 164.7 pg/ml, in women at late pregnancy, with the deficiency rate as 69.6%, while the median level of serum folate was 7.6 ng/ml, with the deficiency rate as 12.1%. 58.4% of these women presented simple vitamin B(12) deficiency and 0.9% with simple folate deficiency. Women living in rural areas showed lower levels of both vitamin B(12) and folate than the women from the urban areas. Both the levels of vitamin B(12) and folate increased with age but were significantly lower in women under the age of 25. Among those with or without folate deficiency, the average difference in the levels of vitamin B(12) was 37.62 pg/ml. Quantile regression models showed that the vitamin B(12) levels in women with folate deficiency were significantly lower than those without, despite the different levels of vitamin B(12). This difference appeared increasing along with the increase of the vitamin B(12) levels. Conclusions: Our data showed that both vitamin B(12) and folate were deficient in women awaiting delivery, in Shaanxi. We suggest that vitamin B(12) should also be added into the folic acid supplementation program, together with the reinforcement on health education program to improve the awareness of nutrient supplementation in rural and young women. Hopefully, these strategies could increase the levels of both vitamin B(12) and folate, in the province.

[Association between maternal passive smoking during perinatal period and congenital heart disease in their offspring-based on a case-control study].

Objective: To explore the association between maternal passive smoking during perinatal period and congenital heart disease (CHD) in their offspring. Methods: A case-control study was designed. Data being used was based on a case-control study of congenital heart disease collected in Shaanxi province from January 2014 to December 2016. Cases under this study were perinatal infants diagnosed as CHD from 28 weeks of gestation to 7 days after birth, and fetus less than 28 weeks of gestation but diagnosed as CHD by ultrasonography. The controls would include newborn infants without any birth defects, born at the same period of the cases. Logistic regression model with confounding factors adjusted was established to analyze the association between maternal passive smoking status during perinatal period and CHD in their offspring. Subgroup analysis was carried out to explore its stability. Results: A total of 2 259 subjects, consisting 695 cases and 1 564 controls were included in this study. Passive smokers accounted for 26.76% in the case group while only 6.01% in the control group. After adjusting for related confounding factors, the risk of CHD in the offspring of passive smokers was 3.32 times higher than that of the non-passive smokers (OR=3.32, 95%CI: 2.41-4.56), during the perinatal period. Results also showed that related risk accumulated with the increase of exposure frequency to passive smoking. For mothers who smoked passively for 1-3 days per week, the risk of CHD in their offspring was 2.75 times higher than that of those non-passive smokers (OR=2.75, 95%CI: 1.62-4.66). For mothers who smoked passively for more than 3 days per week, the risk was 3.62 times higher than the non-passive smokers (OR=3.62, 95%CI: 2.48-5.29). Data from the subgroup analysis showed that the association between maternal passive smoking during perinatal period and CHD in their offspring appeared stable. Conclusions: Maternal passive smoking during perinatal period seemed a risk factor for congenital heart disease related to their offspring. Pregnant women should avoid exposure to second-hand smoke as much as possible, so as to prevent the harm from passive smoking.

[The association between the frequency of prenatal care in childbearing aged women and risk of small for gestational age among neonatal twins in Shaanxi Province].

Objective: To explore the association between the frequency of prenatal care in childbearing aged women and risk of small for gestational age (SGA) among neonatal twins in Shaanxi Province. Methods: From July to December 2013, a total of 30 027 childbearing aged women, who were pregnant from January 2010 to November 2013 and had definite outcomes, were selected from 30 districts (counties) of Shaanxi Province by using the multi-stage random sampling method. The questionnaires with a face-to-face survey method were used to retrospectively collect demographic information, pregnancy history, lifestyle during pregnancy, disease history, nutritional supplements, and health care during pregnancy. Information on the gestational age and birth weight of the newborn were obtained by consulting the medical certificate of birth and were registered as twin A and twin B by birth order. Finally, 356 childbearing aged women and their twin babies with complete data were included in the analysis. A generalized estimation equation model was used to analyze the association between the frequency of prenatal care and the risk of SGA among neonatal twins. Results: The age of childbearing aged women was (27.44±4.68) years old, of which 79.49% (283 women) were rural residents and 44.38% (158 women) had seven or more times prenatal care. The gestational age and birth weight were (37.64±2.51) weeks and (2 510±497) g, respectively. The prevalence of SGA was 51.40% (183/356) for twin A and 53.37% (190/356) for twin B, respectively. The prevalence of SGA was 44.30% (70/158) for twin A with seven or more times prenatal care and 42.41% (67/158) for twin B with seven or more times prenatal care, which was lower than that for twins with less than seven times prenatal care, respectively [57.07% (113/198) and 62.12% (123/198)] (P values were 0.017 and <0.001). The results of generalized estimation equation model suggested that compared to those with less than seven times prenatal care, after adjusting for parity, birth order, place of residence, maternal age, occupation, education, family wealth index, passive smoking, pregnancy-induced hypertension syndrome, folic acid, and iron supplement during perinatal period, and gender of the newborn, the OR (95%CI) of risk of SGA among childbearing aged women with seven or more times prenatal care was 0.60 (0.40-0.91). Conclusion: Seven or more times prenatal care could reduce the risk of SGA among neonatal twins in Shanxi Province.

[Association between congenital heart disease and maternal disease in early pregnancy in women of childbearing age].

Objective: To investigate the relationship between maternal disease in early pregnancy of women of childbearing age and congenital heart disease of neonates. Methods: A cross-sectional design was used in this study and stratified multistage random sampling method was used. A questionnaire survey was conducted in the childbearing-aged women during 2010-2013 in Shaanxi province. Propensity score (PS) matched (1∶1) analysis was used to match participants with diseases to those without disease in early pregnancy. Through the control of the confounders step by step, a logistic regression model was established to evaluate the ORs of congenital heart disease according to the independent variable of maternal disease. Results: A total of 28 680 pairs of mothers and infants were included in this study, the proportion of the women with disease in early pregnancy was 20.25% (5 807). After PS matching, 5 436 pairs were matched. After adjusting all confounding factors, the multivariable logistic regression analysis results showed that maternal disease (OR=1.86, 95%CI: 1.23-2.81), especially cold (OR=2.19, 95%CI: 1.46-3.28), gynecological disease (OR=4.74, 95%CI: 2.03-11.09) and diabetes (OR=14.00, 95%CI: 1.64-119.21), in early pregnancy were the risk factors for congenital heart disease of neonate. Conclusion: In women of childbearing age, disease in early pregnancy, especially cold, gynecological disease and diabetes, can increase the risk of congenital heart disease in neonates.

[Study on the association of dietary patterns of Shaanxi women of childbearing age during pregnancy with adverse pregnancy outcomes from 2010 to 2012].

Objective: To analyze the types of dietary patterns of women during pregnancy in Shaanxi and their association with adverse pregnancy outcomes. Methods: Data were derived from a cross-sectional program named "The prevalence and risk factors of birth defects in Shaanxi Province" from July to November in 2013. A multi-stage stratified random sampling method was used to extract 15 980 women of childbearing age who met the inclusion exclusion criteria from Shaanxi Province. The questionnaire obtained information such as the pregnancy outcome and the food intake of the study subjects during pregnancy. The dietary pattern was extracted by factor analysis, and the each dietary pattern of subjects were divided into T(1)-T(3) groups according to the factor score. The effects of each dietary pattern on major adverse pregnancy outcomes were estimated by unconditional logistic regression model. Results: Four dietary patterns were established:vegetarian pattern, balanced pattern, traditional pattern, and processing pattern. The multivariate logistic regression model results showed that compared with the vegetarian pattern T(2) group, the T(1) group had lower risk of low birth weight (OR=0.56, 95%CI: 0.41-0.83), and the T(3) group had higher risk of low birth weight in offspring (OR=2.32, 95%CI: 1.59-3.89); compared with the traditional pattern T(2) group, the T(3) group had higher risk of premature (OR=2.62, 95%CI: 1.58-5.01); compared with the balanced pattern T(2) group, the T(3) group had a lower risk of spontaneous abortion (OR=0.73, 95%CI: 0.36-0.89); compared with the processing pattern T(2) group, the T(3) group had a higher risk of spontaneous abortion (OR=1.97, 95%CI: 1.36-3.34) and higher risk of stillbirth (OR=2.96, 95%CI: 1.49-6.26), and the T(1) group had a lower risk of stillbirths in offspring (OR=0.52, 95%CI: 0.33-0.83). Conclusion: The women of childbearing age in Shaanxi have different dietary patterns, and there may be a correlation between dietary patterns and adverse pregnancy outcomes.

[Interaction between pregnancy-induced hypertension and history of preterm birth on the risk of small for gestational age].

Objective: To investigate the interaction of pregnancy-induced hypertension and history of preterm birth on the risk of small for gestational age. Methods: Stratified multistage random sampling method was used to choose samples from 30 districts and counties of Shaanxi province. Information on childbearing-age women with their children between January 2010 and November 2013 was retrospectively collected through face-to-face questionnaire survey. The childbearing-aged women were in pregnancy or having had definite outcomes of pregnancy. Enumeration data were described by percentage, and measurement data were described by Mean±SD, and χ(2) test was used to compare the rates. Unconditional logistic regression analysis was performed to estimate the interaction between pregnancy-induced hypertension and history of preterm birth on the risk of small for gestational age, and by using small for gestational age as dependent variables, pregnancy-induced hypertension and history of preterm birth as independent variables. Confounding factors were under control. Firstly, the association between pregnancy-induced hypertension and small for gestational age has been analyzed in primiparas, secondly, interaction of pregnancy-induced hypertension and history of preterm birth on the risk of small for gestational age has been analyzed in multiparas. Results: A total of 25 751 women of childbearing age and their children were recruited. 60.55% (15 592/25 751) were primiparas, 39.45% (10 159/25 751) were multiparas, the rate of history of preterm birth was 1.89% (192/10 159) for multiparas. The incidence rates of pregnancy-induced hypertension and small for gestational age were 1.55% and 15.49% in pregnant woman (400/25 751) and their newborns (3 990/25 751). Unconditioned logistic regression analysis showed that compared with woman without pregnancy-induced hypertension, primiparas with pregnancy-induced hypertension had increased risk of small for gestational age (OR=1.43, 95%CI: 1.02-2.00, P=0.041). Regarding multiparas, the main effect of pregnancy-induced hypertension had a positive correlation with small for gestational age (OR=1.34, 95%CI: 0.91-1.96), but there was no statistical significance (P=0.138). The main effect of history of preterm birth was positively correlated with small for gestational age (OR=1.61, 95%CI: 1.13-2.31, P=0.009). The interaction term "pregnancy-induced hypertension×history of preterm birth" was positively associated with risk of small for gestational age (OR=5.93, 95%CI: 1.19-29.61, P=0.030). Conclusions: Pregnancy-induced hypertension was associated with increased risk for small for gestational age in both primiparas and multiparas, and history of preterm birth further increased risk for small for gestational age in pregnant women with pregnancy-induced hypertension, indicating that there was multiplication interaction between pregnancy-induced hypertension and history of preterm birth.

[Relationship between preterm birth of infant and medication during pregnancy in women of childbearing age in Shaanxi].

Objective: To understand the relationship between medication during pregnancy and single live preterm birth of infant in women of childbearing age in Shaanxi province. Methods: A cross-sectional design was used in this study and stratified multistage random sampling method was used. A questionnaire survey was conducted in the childbearing-aged women selected through multi stage stratified random sampling in Shaanxi during 2010 to 2013. Qualitative datum was described by percentage and measurement datum was described by mean±standard deviation. Logistic regression analysis was done to evaluate the relationship between medication during pregnancy and preterm birth of infant. Results: The overall incidence rate of premature birth was 2.7% in Shaanxi. Among the 28 841 mothers participating in this study, the proportion of medication use at any time during pregnancy was 15.8%, and the most commonly used drug was cold medicine (5.9%). After adjusting all confounding factors, the multivariable logistic regression analysis results showed that taking hormone medicine (OR=2.23, 95%CI: 1.19-4.18), antihypertensive medicine (OR=7.74, 95%CI: 4.28-13.95) and other medicines (OR=2.15, 95%CI: 1.60-2.89) during early pregnancy were the risk factors for preterm delivery, the risk was 2.23 times, 7.74 times and 2.15 times higher compared with those taking no these medicines. Conclusion: Using hormone medicine, antihypertensive medicine and other medicines during pregnancy increased the risk for preterm delivery in women of childbearing age in Shaanxi.

[Analysis on chronic diseases and risk factors of adult residents in Shaanxi province].

Objective: To explore the prevalence of chronic diseases and related risk factors in Shaanxi province. Methods: Multi-stage stratified cluster random sampling was used to collect the sample from permanent residents in 10 national surveillance points in Shaanxi province in 2015. Behavioral risk factors (smoking, drinking, diet and physical activity) were investigated by face-to-face interviews and biological risk factors (BMI, blood pressure, blood glucose and blood lipid) were collected by physical measurements and laboratory tests. Designed weight, no response weight and post hierarchical weight were taken into account in the data analysis. Binary logistic regression models were used to examine the pair-wise associations among 8 risk factors. Results: A total of 6 174 persons were included in the analysis. The following weighted prevalence were noticed in Shaanxi province in 2015, that including current smoking as 28.19%, harmful use of alcohol as 6.20%, inadequate intake of vegetables and fruits as 55.62%, physical inactivity as 19.56%, overweight and obesity as 46.82%, hypertension as 31.12%, raised fasting blood glucose as 4.27%, and raised total cholesterol as 20.96%. Eight risk factors were found to be associated with each other. The mean numbers of risk factors were 2.41 per male and 1.85 per female, 1.94 per urban resident and 2.28 per rural resident. Conclusions: Risk factors for chronic diseases among adults aged 18 or older were more than the national levels in Shaanxi province in 2015. Male and rural residents presented more risk factors than their counterparts. Correlations between risk factors implied that a combined package of interventions was needed to reduce these risk factors.

[Association between congenital heart disease and medication taken during pregnancy among women of childbearing age].

Objective: To analyze the relationship between medication taken during pregnancy and congenital heart disease of the newborns. Methods: A large cross-sectional survey was conducted between August and November 2013. A questionnaire survey was conducted among the childbearing aged women, selected through multistage stratified random sampling in Shaanxi from 2010 to 2013. All of the childbearing aged women under study were in pregnancy and with definite pregnancy outcomes. Multivariable Poisson regression was conducted for data analyses. Results: A total of 28 680 cases were included in this study. The proportion of medication taken at any time during pregnancy was 16.0%, and the prevalence of congenital heart disease among the newborns was 67.9/10 000. After adjustment for factors as general demographic characteristic, history of heart disease and drug allergy and the situation of disease during pregnancy of these women, results from the multivariable Poisson regression showed that, factors as taking drugs (RR=1.95, 95%CI: 1.42- 2.68), cold medicine (RR=1.68, 95%CI: 1.07-2.64), antibiotics (RR=1.90, 95%CI: 1.25-2.90), salicylates (RR=5.01, 95%CI: 1.84-13.64) and antifungal drugs (RR=10.22, 95%CI: 3.25-32.19) during pregnancy were all related to congenital heart disease, and with the history of taking cold medicine (RR=1.90, 95%CI: 1.01-3.61), antibiotics (RR=2.18, 95%CI: 1.17-4.06), salicylates (RR=6.07, 95%CI: 1.45-25.41), antifungal drugs (RR=21.01, 95%CI: 4.17-105.87) and other drugs (RR=2.31, 95%CI: 1.19-4.47) during early pregnancy. These factors were with higher risks for congenital heart disease. Conclusion: Women of childbearing age who took cold medicine, antibiotics, salicylic acid drugs, antifungal drugs and other drugs during early pregnancy would increase the risks related to congenital heart diseases.

[A propensity score-matched study on relationship between maternal respiratory infection in early pregnancy and gestational age].

Objective: To explore the association between maternal respiratory infection in early pregnancy and gestational age of single live birth. Methods: A face to face questionnaire survey was conducted among child bearing aged women in 30 counties (district) of Shaanxi province selected through stratified multistage sampling. Propensity score (PS) matched (1∶1) analysis was used to match participants with respiratory infections to those without respiratory infections. A multilevel linear model was used to investigate the association between respiratory infections and gestational age. Through the control of the confounders step by step, three models were established in this study: model 1 for the variable of respiratory infections before PS matching, model 2 was adjusted for variables in model 1 plus some other individual differences of mother and baby, and model 3 for the variable of respiratory infections after PS matching. Results: Of 28 848 child bearing aged women surveyed, 3 676 (12.74%) had respiratory infections in early pregnancy. After PS matching, 2 762 pairs were matched. Analysis with model 1 indicated that a decrease of 0.111 week (P<0.001) in gestational age was associated with a respiratory infection during the first trimester. Analysis with model 2 and model 3 indicated that a decrease of 0.058 week (P=0.025) and a decrease of 0.076 week (P=0.036) were associated with respiratory infection during the first trimester, respectively. Conclusion: The respiratory infection during the first trimester was associated with the decrease of the gestational age of newborn.

[Effect of interpregnancy interval of childbearing aged women on birth weight of single live birth neonates].

Objective: To understand the effect of interpregnancy interval (IPI) of childbearing aged women on the birth weight of single live birth neonates in Shaanxi province. Methods: A questionnaire survey was conducted among the childbearing aged women selected through multistage stratified random sampling in Shaanxi during 20l0-2013, all the childbearing aged women had definite pregnancy outcomes. The interpregnancy interval of the childbearing aged women and the birth weight of the newborns were used as the independent variables and dependent variables respectively in multiple linear regression model and quantile regression model, and confounding factors were controlled. Results: A total of 13 063 women at childbearing age and their infants were investigated. The incidence of low birth weight and macrosomia was 3.54% and 7.62% respectively. Multiple linear regression analysis showed that there was no significant difference in birth weight among different IPI group and control group. Quantile regression analysis showed when birth weight was at 5 percentiles, the difference in birth weight between newborns whose mothers had short interpregnancy interval (<12 months) and those in control group was significant, when the birth weight was ≥90 percentiles, the birth weights of newborns whose mothers had long interpregnancy interval (60-119 months) were higher than those in control group, the difference was significant. As the increase of the percentiles of birth weight, the extent of changes gradually increased. Conclusion: The analysis indicated that both short (<12 months) and long (60-119 months) interpregnancy interval would had negative effects on birth weights of newborns. Therefore, planning for pregnancy is important for having a good perinatal outcome.

[Association between illness and mental status in pregnant women and birth defects].

Objective: To understand the prevalence of birth defects, related diseases and mental status of women during pregnancy in Shaanxi province and to analyse the major risk factors on birth defects and congenital heart disease. Possible association between maternal diseases or mental status and the risk of birth defects, was also explored. Methods: A cross-sectional design was used in this study and stratified multistage random sampling method was used. The whole survey was from Jury 2013 to November 2013. Logistic regression method was used to analyze the association between maternal diseases, mental status during pregnancy and birth defects. Results: The overall prevalence of birth defects was 195.04 per 10 000 in Shaanxi. Among the 29 121 mothers participating in this study, 51.1% developed illness and 6.8% "changed their mental status during pregnancy. After adjusting all the confounding factors, results showed that, histories of cold" , fever, and intrahepatic cholestasis were (OR=1.33, 95%CI: 1.10-1.61, OR=1.54, 95%CI: 1.09-2.16, and OR=32.77, 95%CI:4.08-263.04) respectively, during pregnancy that related to birth defects. Self-reported unstable mental status (OR=1.60, 95%CI: 1.19-2.15) and family friction (OR=2.07, 95%CI: 1.12-3.79) were both related to the birth rates. Histories of cold and fever (OR=1.59, 95%CI: 1.28-1.98; OR=1.43, 95%CI: 1.48-4.00), during early pregnancy, unstable mental status during mid-pregnant period (OR=1.52, 95%CI: 1.05-2.19), unstable mental status during late-pregnant period (OR=1.63, 95%CI: 1.05-2.19) and family friction during late-pregnant period (OR=2.89, 95%CI: 1.16-7.20) were found to be related to birth defects. Compared with those without history of cold, those with the history of cold during first (OR=1.24, 95%CI: 1.02-1.52) and second stages (OR=2.06, 95%CI: 1.30-3.26) of pregnancy were more likely to bear fetus with birth defects. Compared with those without these histories, those with histories of fever (OR=1.49, 95%CI: 1.04-2.13), emotional problem (OR=1.71, 95%CI: 1.19-2.45) and related diseases (OR=2.67, 95%CI: 1.32-5.39) during the first period of pregnancy were more likely to bear fetus with birth defects. Conclusion: The incidence of birth defects in Shaanxi was high. Histories of cold, fever, unstable mental status and family friction during pregnancy, seemed to have increased the risks of bearing child with birth defects.