[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.

[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.

[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.

[Prenatal supplementations of iron, iron-containing multimicronutrients and antianemic Chinese patent medicines in women in Shaanxi province, 2010-2013].

Objective: To understand the prevalence of prenatal supplementations of iron, iron-containing multi-micronutrients (IMMN) and antianemic Chinese patent medicines (ACPM) and associated factors in women in Shaanxi province. Methods: A sample of 28 367 childbearing-age women who gave birth during 2010-2013 and had specific information of the prenatal nutrients supplementation were recruited using stratified multistage cluster random sampling in Shaanxi province. The information about their basic characteristics and prenatal supplementation of nutrients were collected by a questionnaire survey. Descriptive analysis method was used to analyze the intake rate of iron, IMMN and ACPM during each period of pregnancy, and logistic regression model was used to identify associated factors. Results: The overall prevalence of prenatal iron, IMMN and ACPM supplementation was low (28.99%), and the intake rate of iron was the lowest (5.33%). The prevalence of prenatal supplementation of iron, IMMN and ACPM were lower before pregnancy and in the first trimester than in the second and third trimester. The intake rates for consecutive 2 periods were very low (all were lower than 2.00%). The intake rates of iron, IMMN and ACPM significantly increased year by year. Women living in central Shaanxi had relatively high intake rates of iron (7.22%) and IMMN (16.55%), and women in southern Shaanxi had relatively high intake rate of ACPM (18.50%). The results of logistic regression analysis showed that higher educational level (OR=1.920, 95%CI: 1.617-2.279), antenatal care times≥6 (OR=1.832, 95%CI: 1.604-2.091), etc. were the positive factors for iron intake, and these positive factors were similar to those for IMMN intake. Additionally, rural residence was the negative factor for IMMN intake (compared with urban residence, OR=0.872, 95%CI: 0.788-0.966). Conversely, higher educational level (OR=0.855, 95%CI: 0.746-0.979), higher household income (OR=0.864, 95%CI: 0.796-0.938) were negative factors for ACPM intake, and rural residence was its positive factor (OR=1.285, 95%CI: 1.141-1.447). Conclusions: The prevalence of prenatal supplementation of iron, IMMN and ACPM were low in women in Shaanxi, especially the intake rate of iron was the lowest. The prophylactic iron supplementation before pregnancy or in the first trimester was rare. Measures should be taken to improve the prenatal supplementation of iron in Shaanxi and to standardize the clinical use of ACPM.

[Factors related to the influence on congenital malformation of body surface in Shaanxi province].

Objective: To investigate the influencing factors on congenital malformation of body surface. Methods: Multi-stage stratified random sampling method was adopted. A questionnaire survey was conducted among the childbearing aged women who experienced more than 28 weeks pregnancy or having definite pregnancy outcomes in Shaanxi, during 2010-2013. Results: Results from the logistic regression model showed that factors as: intrahepatic cholestasis of pregnancy (OR=21.76, 95%CI: 4.46-106.25), histories with abnormal pregnancy or reproduction (OR=11.88, 95%CI: 9.14-15.45), having birth defects in the family (OR=6.15, 95%CI: 2.66-14.23), being twins (OR=5.74, 95% CI: 3.34-9.86), being worker (compared with others, OR=2.47, 95% CI: 1.30-4.68) or farmer (compared with others, OR=1.91, 95%CI: 1.14-3.20), less than 4 times of antenatal care (compared with >7, OR=1.84, 95% CI: 1.28-2.64), occupational exposure to related risks during pregnancy (OR=1.74, 95% CI: 1.26-2.42), mother's hometown was from mid-part of Shaanxi (compared with northern Shaanxi, OR=1.65, 95%CI: 1.20-2.28), mother's native residence was from the rural areas (OR=1.75, 95% CI: 1.13-2.71), drug use (OR=1.64, 95% CI: 1.26-2.13) etc. were risk factors for congenital malformation of body surface. Iron supplement during pregnancy (OR=0.46, 95%CI: 0.21-0.99) appeared as protective factor for congenital malformation of body surface. Conclusion: The following factors seemed to be of risk for congenital malformation of body surface, including: mother's native area was from the middle part of Shaanxi and living in rural area, being worker or farmer, histories of abnormal pregnancy and reproduction, history of birth defects in the family, being twins, with antenatal care less than 4 times, occupational exposure to dangerous materials, drug use, intrahepatic cholestasis during pregnancy etc.

[Effect of folic acid supplementation in childbearing aged women during pregnancy on neonate birth weight in Shaanxi province].

OBJECTIVE: To investigate the effect of folic acid supplementation in childbearing aged women during pregnancy on the birth weight of newborns in Shaanxi province. METHODS: A questionnaire survey was conducted among the childbearing aged women selected through multistage stratified random sampling in Shaanxi during 2010-2013, all of these childbearing aged women were in pregnancy or had definite pregnancy outcomes. The birth weight of newborns and folic acid supplementation during pregnancy were used as the dependent variables and independent variables respectively in multiple linear regression model and quantile regression model and confounding factors were controlled. RESULTS: Multiple linear regression analysis showed that the birth weight of newborns whose mothers had folic acid supplementation during pregnancy were significantly higher than those whose mothers had no folic acid supplementation during pregnancy, an average increase of 29.56 g(B=29.56, t=4.69 and P<0.01). Quantile regression analysis showed from very low to higher percentiles(q=0-0.55, q=0.65, q=0.75-0.80), the birth weights of newborns whose mothers supplemented folic acid were higher than those whose mother did not supplement folic acid, the difference was significant, but the increase varied. As the increase of the percentiles of birth weight, the body weight increase declined gradually in those whose mothers had folic acid supplementation compared with those whose mothers had no folic acid supplementation. CONCLUSION: Folic acid supplementation during pregnancy can increase the birth weight of newborns, the influence was greater in newborns with lower body weight than in newborns with higher body weight.

[Meta-analysis on effect of combined supplementation of folic acid, vitamin B12 and B6 on risk of cardio-cerebrovascular diseases in randomized control trials].

OBJECTIVE: To evaluate the effect of the combined supplementation of folic acid, vitamin B12 and B6 on the risk of cardio-cerebrovascular diseases. METHODS: The literatures of randomized control trials about the relationship between the combined supplementation of folic acid, vitamin B12 and B6 and risk of cardio-cerebrovascular diseases from 1980 to 2014 were retrieved, and the eligible studies were screened for a Meta-analysis. The study indicators were the incidences of cardiovascular disease events, myocardial infarction and stroke. The cffect indicators were relative risk(RR)and 95% confidence interval(CI). Jadad score was used for the quality evaluation of the trials used in the study. RESULTS: The literatures of 11 randomized control trials, involving 26 395 patients, were used in the Meta-analysis. The combined supplementation of B vitamins had no effect on the incidence of cardiovascular disease events(RR=1.00, 95% CI: 0.94-1.07)based on 8 studies. The combined supplementation of B vitamins had no effect on the incidence of myocardial infarction(RR= 1.03, 95% CI: 0.94-1.13)based on 9 studies. The combined supplementation of B vitamins could reduce the incidence of stroke by 14%(RR=0.86, 95%CI: 0.78-0.95)based on 9 studies. Compared with the control group, Taking folic acid combined with vitamin B12 and B6 could reduce the level of homocysteine by 2.53 µmol/L(95%CI:-3.93--1.12). Subgroup analysis indicated that the follow-up time, the dosage of folic acid and vitamin B12 and B6, the history of diseases had no confounding effect on the incidence of cardio-cerebrovascular disease events. But the subgroup analysis for stroke showed that with the extension of follow-up time, the supplementation of B vitamins could reduce the risk of stroke. The effect of folic acid and B12 in small dosage seemed more significant in the prevention of stroke, while the preventive effect of B6 increased with increasing dosage. The preventive effect of combined supplementation of B vitamins was more significant for the patients with a history of cardio-cerebrovascular diseases. CONCLUSION: Taking folic acid combined with vitamin B6 and B12 might have no significant effect on the incidences of cardio-cerebrovascular disease events and myocardial infarction, but could lower the risk of stroke and the level of homocysteine.