Demographic variations and temporal trends in prenatal use of multiple micronutrient supplements in Beijing, 2013-2017

Third trimester as the susceptibility window for maternal PM2.5 exposure and preterm birth: A nationwide surveillance-based association study in China

Maternal PM_2.5 exposure has been identified as a potential risk factor for preterm birth, yet the inconsistent findings on the susceptible exposure windows may be partially due to the influence of gaseous pollutants. This study aims to examine the association between PM_2.5 exposure and preterm birth during different susceptible exposure windows after adjusting for exposure to gaseous pollutants. We collected 2,294,188 records of singleton live births from 30 provinces of China from 2013 to 2019, and the gridded daily concentrations of air pollutants (including PM_2.5, O₃, NO₂, SO₂, and CO) were derived by using machine learning models for assessing individual exposure. We employed logistic regression to develop single-pollutant models (including PM_2.5 only) and co-pollutant models (including PM_2.5 and a gaseous pollutant) to estimate the odds ratio for preterm birth and its subtypes, with adjustment for maternal age, neonatal sex, parity, meteorological conditions, and other potential confounders. In the single-pollutant models, PM_2.5 exposure in each trimester was significantly associated with preterm birth, and the third trimester exposure showed a stronger association with very preterm birth than that with moderate to late preterm birth. The co-pollutant models revealed that preterm birth might be significantly associated only with maternal exposure to PM_2.5 in the third trimester, and not with exposure in the first or second trimester. The observed significant associations between preterm birth and maternal PM_2.5 exposure in the first and second trimesters in single-pollutant models might primarily be influenced by exposure to gaseous pollutants. Our study provides evidence that the third trimester may be the susceptible window for maternal PM_2.5 exposure and preterm birth. The association between PM_2.5 exposure and preterm birth could be influenced by gaseous pollutants, which should be taken into consideration when evaluating the impact of PM_2.5 exposure on maternal and fetal health.

Joint Effects of Prenatal Folic Acid Supplement with Prenatal Multivitamin and Iron Supplement on Obesity in Preschoolers Born SGA: Sex Specific Difference

Prenatal maternal nutrient supplementation has been reported to be associated with offspring obesity, but the reports are inconsistent and have mainly ignored the differences between the total children population and children born small for gestational age (SGA). This study aimed to examine the joint effects of folic acid, iron, and multivitamin supplementation during pregnancy on the risk of obesity in preschoolers born SGA. A total of 8918 children aged 3-6.5 years born SGA were recruited from Longhua District in Shenzhen of China in 2021. Their mothers completed a structured questionnaire about the child's and parents' socio-demographic characteristics, maternal prepregnant obesity, and mothers' prenatal supplementation of folic acid, iron, and multivitamin. In addition, the children's current weight and height were measured by trained nurses. Logistic regression models were used to analyze the associations between prenatal supplementations and the current presence of childhood obesity. After controlling for potential confounders, the results of the logistic regression analysis showed that prenatal supplement of folic acid (OR = 0.72, 95% CI = 0.55~0.93) was associated with a lower likelihood of being an obese preschooler born SGA. In contrast, the ingestion of multivitamin or iron supplements during pregnancy did not seem to be related to the likelihood of childhood obesity in preschoolers born SGA. Moreover, cross-over analysis of prenatal folic acid and multivitamin obtained significant negative associations of prenatal folic acid supplement only (OR = 0.73, 95% CI = 0.55~0.97) and combination supplement of folic acid and multivitamin (OR = 0.67, 95% CI = 0.50~0.90) with obesity of preschoolers born SGA; while the cross-over analysis of prenatal folic acid and iron observed significant negative associations between obesity of preschoolers born SGA and a combination supplement of folic acid and iron (OR = 0.70, 95% CI = 0.52~0.96). Furthermore, the aforementioned significant associations were only found in girls and not in boys when the analyses were stratified by sex. Our findings suggest that the prenatal folic acid supplementation may decrease the risk of obesity in preschool girls born SGA, and that this effect may be modified by prenatal multivitamin or iron supplementation.

[Relationship between micronutrients supplementation during periconceptional period and serum concentration of vitamin E in the 1st trimester of gestational period]

OBJECTIVE

To explore the association of maternal periconceptional folic acid or multiple micronutrients supplementation during periconceptional period and the serum vitamin E (Vit.E) concentration in the 1st trimester of gestational period.

METHODS

A retrospective cohort study was conducted based on the prenatal health care system and clinical laboratory information system. Totally, 22 171 pregnant women who had their prenatal health care and gave birth in Tongzhou Maternal & Child Health Hospital of Beijing from Jan. 2016 to Dec. 2018 were recruited. The usage patterns of nutritional supplements [folic acid (FA) or multiple micronutrients (MM)] during periconceptional period were independent variables, and serum Vit.E concentration and serum Vit.E concentration≥11.2 mg/L in the 1st trimester of gestational period were outcome variables for generalized linear regression model and Logistic regression model, respectively, to analyze the relationships between the independent and outcome variables.

RESULTS

The range of the serum Vit.E concentration in the 1st trimester of gestational period was 5.2-24.0 mg/L, and the median concentration was 10.1 (8.8-11.6) mg/L; the excess rate of the serum Vit.E of those who took MM supplementation was 0.3%, and the rates for the groups of FA only or no nutritional supplements used were both 0.1%. Compared with women without nutritional supplement or the women taking FA, the women who took MM had higher serum Vit.E levels in the 1st trimester of gestational period (both P < 0.05). The women taking FA or MM initiated before the conception showed that the serum Vit.E concentration in the 1st trimester of gestational period was higher than that after the conception (P < 0.05), and the serum Vit.E concentration of women who took regularly was higher than that of irregular taking (P < 0.05); with taking compliance elevated, the serum Vit.E concentration of the two groups of women taking FA or MM increased (P < 0.05). The risk of serum Vit.E concentration≥11.2 mg/L among the women taking MM was higher than that of the women without nutritional supplements or taking FA only [odds ratio (OR)=1.36, 95% confidence interval (95%CI): 1.21-1.53; OR=1.39, 95%CI: 1.31-1.48)]; women who took FA or MM showed a lower risk for serum Vit.E concentration≥11.2 mg/L of taking it after the conception than before, the ORs (95%CI) were 0.86 (95%CI: 0.77-0.96) and 0.88 (95%CI: 0.81-0.95), respectively; the women taking the two supplements regularly had higher risk for serum Vit.E concentration≥11.2 mg/L than irregular taking, the ORs (95%CI) were 1.16 (95%CI: 1.05-1.29) and 1.13 (95%CI: 1.04-1.22) for FA and MM users, respectively; with the compliance increasing, the women taking MM had a higher risk of serum Vit.E levels≥11.2 mg/L in the 1st trimester [OR (95%CI) was 1.10 (1.07-1.14)], but for FA users, the OR (95%CI) was 1.04(1.00-1.08).

CONCLUSION

Vit.E nutritional status in women in early gestational period in Beijing was generally good, and the excess rate of serum Vit.E was higher in women who took MM during periconceptional period than those without nutritional supplement or taking FA only, suggesting that women need to consider their own Vit.E nutritional status to choose the type of nutritional supplements during periconceptional period, so as to avoid related health hazards.

[Relationship between micronutrients supplementation during periconceptional period and serum concentration of vitamin E in the 1st trimester of gestational period]

OBJECTIVE

To explore the association of maternal periconceptional folic acid or multiple micronutrients supplementation during periconceptional period and the serum vitamin E (Vit.E) concentration in the 1st trimester of gestational period.

METHODS

A retrospective cohort study was conducted based on the prenatal health care system and clinical laboratory information system. Totally, 22 171 pregnant women who had their prenatal health care and gave birth in Tongzhou Maternal & Child Health Hospital of Beijing from Jan. 2016 to Dec. 2018 were recruited. The usage patterns of nutritional supplements [folic acid (FA) or multiple micronutrients (MM)] during periconceptional period were independent variables, and serum Vit.E concentration and serum Vit.E concentration≥11.2 mg/L in the 1st trimester of gestational period were outcome variables for generalized linear regression model and Logistic regression model, respectively, to analyze the relationships between the independent and outcome variables.

RESULTS

The range of the serum Vit.E concentration in the 1st trimester of gestational period was 5.2-24.0 mg/L, and the median concentration was 10.1 (8.8-11.6) mg/L; the excess rate of the serum Vit.E of those who took MM supplementation was 0.3%, and the rates for the groups of FA only or no nutritional supplements used were both 0.1%. Compared with women without nutritional supplement or the women taking FA, the women who took MM had higher serum Vit.E levels in the 1st trimester of gestational period (both P < 0.05). The women taking FA or MM initiated before the conception showed that the serum Vit.E concentration in the 1st trimester of gestational period was higher than that after the conception (P < 0.05), and the serum Vit.E concentration of women who took regularly was higher than that of irregular taking (P < 0.05); with taking compliance elevated, the serum Vit.E concentration of the two groups of women taking FA or MM increased (P < 0.05). The risk of serum Vit.E concentration≥11.2 mg/L among the women taking MM was higher than that of the women without nutritional supplements or taking FA only [odds ratio (OR)=1.36, 95% confidence interval (95%CI): 1.21-1.53; OR=1.39, 95%CI: 1.31-1.48)]; women who took FA or MM showed a lower risk for serum Vit.E concentration≥11.2 mg/L of taking it after the conception than before, the ORs (95%CI) were 0.86 (95%CI: 0.77-0.96) and 0.88 (95%CI: 0.81-0.95), respectively; the women taking the two supplements regularly had higher risk for serum Vit.E concentration≥11.2 mg/L than irregular taking, the ORs (95%CI) were 1.16 (95%CI: 1.05-1.29) and 1.13 (95%CI: 1.04-1.22) for FA and MM users, respectively; with the compliance increasing, the women taking MM had a higher risk of serum Vit.E levels≥11.2 mg/L in the 1st trimester [OR (95%CI) was 1.10 (1.07-1.14)], but for FA users, the OR (95%CI) was 1.04(1.00-1.08).

CONCLUSION

Vit.E nutritional status in women in early gestational period in Beijing was generally good, and the excess rate of serum Vit.E was higher in women who took MM during periconceptional period than those without nutritional supplement or taking FA only, suggesting that women need to consider their own Vit.E nutritional status to choose the type of nutritional supplements during periconceptional period, so as to avoid related health hazards.

Association of serum vitamin D status with gestational diabetes mellitus and other laboratory parameters in early pregnant women

Background

The association between serum 25-hydroxy vitamin D (25(OH)D) status and gestational diabetes mellitus (GDM) gained attention in recent years, however the conclusion is still controversial due to many interfering factors, such as region of living, environment, lifestyle, and food supplements. Other metabolites (laboratory parameters) are also important in reflecting gestational states. This study aimed to investigate the association of serum 25(OH)D status in early pregnancy with GDM and other laboratory parameters in pregnant women.

Methods

A total of 1516 pregnant women whose blood glucose were normal before pregnancy in the city of Foshan in Guangdong, China were enrolled in this study. GDM was diagnosed between 24 to 28 weeks of pregnancy following the guidelines from the American Diabetes Association. Maternal serum 25(OH)D and other laboratory parameters—including hematology, coagulation, chemistry, and bone density—were measured utilizing various analytical methods in clinical laboratory at gestational weeks 11 to 14.

Results

The average 25(OH)D concentration was 59.1 ± 12.6 nmol/L. None of the study subjects had 25(OH)D < 25 nmol/L; 434 (28.6%) women had 25(OH)D deficiency (< 50 nmol/L), 882 women (58.2%) had 25(OH)D insufficiency (50–74 mmol/L) and 200 women (13.2%) had 25(OH)D sufficiency (≥ 75 nmol/L). There were 264 (17.4%) women diagnosed with GDM. There was not, however, an association between serum 25(OH)D in early pregnancy and GDM. Interestingly, women with more parity and high serum alkaline phosphatase levels had higher serum 25(OH)D levels. There was a possible positive association between serum 25(OH)D and pre-albumin, and a possible negative association between serum 25(OH)D, creatinine, and thrombin time. This study did not find an association between serum 25(OH)D and bone density.

Conclusions

There were no associations between maternal serum 25(OH)D concentration in early pregnancy and the risk of GDM or bone density. There were, however, correlations between serum 25(OH)D and parity, seasoning at sampling, serum alkaline phosphatase, creatinine, pre-albumin, and coagulation factor thrombin time, which need further study to explain their pathophysiology and clinical significance.