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.

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.

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.