Association Between Maternal Serum Folate Concentrations in the First Trimester and the Risk of Birth Defects: The Hokkaido Study of Environment and Children's Health

Association of maternal weight gain in early pregnancy with congenital heart disease in offspring: a China birth cohort study

OBJECTIVES

Little study has reported the association of maternal weight gain in early pregnancy with fetal congenital heart disease (CHD). We aimed to explore the potential relationship based on a China birth cohort while adjusting by multiple factors.

DESIGN

Cohort study.

SETTING

China birth cohort study conducted from 2017 to 2021.

PARTICIPANTS

The study finally included 114 672 singleton pregnancies in the 6-14 weeks of gestation, without missing data or outliers, loss to follow-up or abnormal conditions other than CHD. The proportion of CHD was 0.65% (749 cases).

PRIMARY AND SECONDARY OUTCOME MEASURES

Association between maternal pre-pregnancy weight gain and CHD in the offspring were analysed by multivariate logistic regression, with the unadjusted, minimally adjusted and maximally adjusted methods, respectively.

RESULTS

The first-trimester weight gain showed similar discrimination of fetal CHD to that period of maternal body mass index (BMI) change (DeLong tests: p=0.091). Compared with weight gain in the lowest quartile (the weight gain less than 0.0 kg), the highest quartile (over 2.0 kg) was associated with a higher risk of fetal CHD in unadjusted (OR 1.36, 95% CI: 1.08 to 1.72), minimally adjusted (adjusted OR (aOR) 1.29, 95% CI: 1.02 to 1.62) and maximally adjusted (aOR 1.29, 95% CI: 1.02 to 1.63) models. The association remains robust in pregnant women with morning sickness, normal pre-pregnancy BMI, moderate physical activity, college/university level, natural conception or with folic acid (FA) and/or multivitamin supplementation.

CONCLUSIONS AND RELEVANCE

Although the association of maternal pre-pregnancy weight gain on fetal CHD is weak, the excessive weight gain may be a potential predictor of CHD in the offspring, especially in those with morning sickness and other conditions that are routine in the cohort, such as normal pre-pregnancy BMI, moderate physical activity, college/university level, natural conception or with FA and/or multivitamin supplementation.

Association Between Maternal Factors in Early Pregnancy and Congenital Heart Defects in Offspring: The Japan Environment and Children's Study

Background Many prenatal factors are reported to be associated with congenital heart defects (CHD) in offspring. However, these associations have not been adequately examined using large-scale birth cohorts. Methods and Results We evaluated a data set of the Japan Environmental and Children's Study. The primary outcome was a diagnosis of CHD by age 2 years. We defined the following variables as exposures: maternal baseline characteristics, fertilization treatment, maternal history of diseases, socioeconomic status, maternal alcohol intake, smoking, tea consumption, maternal dietary intake, and maternal medications and supplements up to 12 weeks of gestation. We used multivariable logistic regression analysis to assess the associations between various exposures and CHD in offspring. A total of 91 664 singletons were included, among which 1264 (1.38%) had CHD. In multivariable analysis, vitamin A supplements (adjusted odds ratio [aOR], 5.78 [95% CI, 2.30-14.51]), maternal use of valproic acid (aOR, 4.86 [95% CI, 1.51-15.64]), maternal use of antihypertensive agents (aOR, 3.80 [95% CI, 1.74-8.29]), maternal age ≥40 years (aOR, 1.59 [95% CI, 1.14-2.20]), and high maternal hemoglobin concentration in the second trimester (aOR, 1.10 per g/dL [95% CI, 1.03-1.17]) were associated with CHD in offspring. Conclusions Using a Japanese large-scale birth cohort study, we found 6 maternal factors to be associated with CHD in offspring.

Periconception Red Blood Cell Folate and Offspring Congenital Heart Disease : Nested Case-Control and Mendelian Randomization Studies

BACKGROUND

Periconception folic acid supplementation has been suggested to protect against congenital heart disease (CHD), but the association between maternal red blood cell (RBC) folate, the gold-standard biomarker of folate exposure, and subsequent offspring CHD risk is lacking.

OBJECTIVE

To quantify the association between periconception maternal RBC folate and offspring CHD risk.

DESIGN

Prospective, nested, case-control study and 1-sample Mendelian randomization. (ClinicalTrials.gov: NCT02737644).

SETTING

29 maternity institutions in 12 districts of Greater Shanghai, China.

PARTICIPANTS

All 197 mothers of offspring with CHD and 788 individually matched mothers of unaffected offspring from the SPCC (Shanghai Preconception Cohort).

MEASUREMENTS

Maternal RBC folate was measured before or at early pregnancy. Odds ratios [ORs] were estimated using conditional logistic regression after adjustment for covariates. Mendelian randomization was done using the methylenetetrahydrofolate reductase (MTHFR) C677T as the genetic instrument.

RESULTS

Case patients had lower median maternal RBC folate concentrations than control participants (714 nmol/L [interquartile range, 482 to 1008 nmol/L] vs. 788 nmol/L [557 to 1094 nmol/L]). Maternal RBC folate concentrations were inversely associated with offspring CHD (adjusted OR per 100 nmol/L, 0.93 [95% CI, 0.89 to 0.99]). The adjusted OR for mothers with periconception RBC folate of 906 nmol/L or more (vs. <906 nmol/L) was 0.61 (CI, 0.40 to 0.93). Mendelian randomization showed that each 100-nmol increase in maternal RBC folate concentrations was significantly associated with reduced offspring CHD risk (OR, 0.75 [CI, 0.61 to 0.92]).

LIMITATION

Potential confounding due to unmeasured covariates in the nested case-control study.

CONCLUSION

Higher maternal RBC folate is associated with reduced offspring CHD risk. For primary CHD prevention, higher target RBC folate levels than currently recommended for neural tube defect prevention may be needed and warrant further study.

PRIMARY FUNDING SOURCE

National Key Research and Development Program of China, National Natural Science Foundation of China, China Postdoctoral Science Foundation, and Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences.

Maternal exposure to sulfur dioxide and the risk of oral clefts in Liaoning Province, China: a population-based case-control study

There is limited and equivocal epidemiological evidence relating to the association between maternal sulfur dioxide (SO₂) exposure and the risk of oral clefts (OCs) in offspring. We performed a population-based case-control study in Liaoning province to evaluate aforementioned relationship during 3 months before conception, the first trimester of pregnancy, and their single months. The study involved 3086 patients with OCs and 7950 controls. Data relating to SO₂ concentration was acquired from air monitoring stations throughout the study period. We used a multivariable logistic regression model to evaluate the association between exposure to SO₂ and the risk of OCs during the exposure windows. Maternal SO₂ exposure was positively related to OCs during the 3 months before conception (odds ratio = 1.38, 95% confidence interval: 1.15-1.65; P for trend < 0.01). Positive relationships were obtained from the first and second months before conception and the first month of pregnancy. Thus, our research reflects a relationship between SO₂ exposure and the risk of OCs. Future studies are now required to verify the association between SO₂ exposure and OCs during pregnancy and indicate the most relevant vulnerable exposure time windows.

Hokkaido birth cohort study on environment and children's health: cohort profile 2021

BACKGROUND

The Hokkaido Study on Environment and Children's Health is an ongoing study consisting of two birth cohorts of different population sizes: the Sapporo cohort and the Hokkaido cohort. Our primary objectives are to (1) examine the effects that low-level environmental chemical exposures have on birth outcomes, including birth defects and growth retardation; (2) follow the development of allergies, infectious diseases, and neurobehavioral developmental disorders, as well as perform a longitudinal observation of child development; (3) identify high-risk groups based on genetic susceptibility to environmental chemicals; and (4) identify the additive effects of various chemicals, including tobacco.

METHODS

The purpose of this report is to provide an update on the progress of the Hokkaido Study, summarize recent results, and suggest future directions. In particular, this report provides the latest details from questionnaire surveys, face-to-face examinations, and a collection of biological specimens from children and measurements of their chemical exposures.

RESULTS

The latest findings indicate different risk factors of parental characteristics on birth outcomes and the mediating effect between socioeconomic status and children that are small for the gestational age. Maternal serum folate was not associated with birth defects. Prenatal chemical exposure and smoking were associated with birth size and growth, as well as cord blood biomarkers, such as adiponectin, leptin, thyroid, and reproductive hormones. We also found significant associations between the chemical levels and neuro development, asthma, and allergies.

CONCLUSIONS

Chemical exposure to children can occur both before and after birth. Longer follow-up for children is crucial in birth cohort studies to reinforce the Developmental Origins of Health and Disease hypothesis. In contrast, considering shifts in the exposure levels due to regulation is also essential, which may also change the association to health outcomes. This study found that individual susceptibility to adverse health effects depends on the genotype. Epigenome modification of DNA methylation was also discovered, indicating the necessity of examining molecular biology perspectives. International collaborations can add a new dimension to the current knowledge and provide novel discoveries in the future.

The Xi'an longitudinal mother-child cohort study: design, study population and methods

The large-scale Xi'an longitudinal mother-child cohort study has started to enroll pregnant women who attended Northwest Women's and Children's Hospital (NWCH) for antenatal care in early pregnancy (less than 20 weeks' gestation) from January 2013 and the enrollment will be ended in January 2023. We aimed to investigate the role of external factors (i.e., diet and environment) and internal (i.e., biological, genetic and epigenetic) on the short- and long-term outcomes of mothers and children up to at least 12 years. Mothers completed all routine prenatal care during pregnancy and four times of follow-up at 42 days, 3, 6 and 12 years after delivery, respectively. For children, birth information were obtained from routine medical records and the follow-up information were obtained from child health care clinics of NWCH at age 42 days, 6, 12 and 24 months, then by interviewing mothers every two years until 12 years old. A range of data (including biological, demographic, birth outcomes/birth defects and nutritional factors from both maternal and off-spring) were collected by both interviews and laboratory tests. By June 30th 2019, a total of 114,946 mothers and 124,454 live births had been recruited.

Identifying a risk score for childhood obesity based on predictors identified in pregnant women and 1-year-old infants: An analysis of the data of the Hokkaido Study on Environment and Children's Health

This study aimed to construct a childhood obesity risk index based on predictors identified in pregnant women and 1-yr-old infants. The primary outcome was an identified obesity index of > 20% at 6–8 yr of age. Of a total sample size of 6,846 mother-child pairs, 80% and 20% were randomly allocated to the derivation and validation cohorts, respectively. For the derivation cohort, univariate and multivariate logistic regression analyses of data were conducted to identify the final predictors to determine the childhood obesity risk score algorithm. These included pre-pregnancy body mass index (BMI), child’s gender, smoking during pregnancy, education, and obesity index at one yr of age. The β coefficients for categories of predictor variables were each divided by the smallest value among them. The quotient was rounded off to the integer and assigned to the risk score, and a value of zero was assigned to reference categories. A total risk score was calculated for each individual. A cutoff point ≥ 16 had 22.2% and 21.8% positive predictive values in the derivation and validation cohorts, respectively. In conclusion, the childhood obesity risk score algorithm was constructed based on generic predictors that can be easily obtained from maternal and child health handbooks.

Associations between the Level of Trace Elements and Minerals and Folate in Maternal Serum and Amniotic Fluid and Congenital Abnormalities

Congenital birth defects may result in a critical condition affecting the baby, including severe fetal/neonatal handicap and mortality. Several studies have shown that genetic, nutritional, and environmental factors may have an impact on fetal development and neonatal health. The relevance of essential and toxic elements on fetal development has not yet been fully investigated, and the results of recent research indicate that these elements may be crucial in the assessment of the risk of malformations in neonates. We determined the association between essential and toxic elements and the level of folate in maternal serum (MS) and amniotic fluid (AF), along with neonatal abnormalities. A total of 258 pregnant Polish women in the age group of 17⁻42 years participated in this study. AF and MS were collected during vaginal delivery or during cesarean section. An inductively coupled plasma mass spectrometry technique was used to determine the levels of various elements in AF and MS. The results of this exploratory study indicate that the levels of essential and toxic elements are associated with fetal and newborn anatomical abnormalities and growth disorders.