Congenital malformations are associated with secondhand smoke among nonsmoking women: A meta-analysis

Maternal consumption of caffeine and second-hand tobacco smoke as risk factors for the development of oral clefts

OBJECTIVE

The aim of this case-control study was to investigate environmental factors, such as caffeine, folic acid, nutritional iron supplementation, multivitamin complexes, alcohol, and tobacco (second-hand smoking), which have been described as risk factors for the development of oral clefts.

METHODS

This case-control study employed convenience sampling and included 409 mothers: 132 with children with oral clefts (cases) and 277 with children without oral clefts (controls). The age range of the children in both groups was 0 to 2 years. A questionnaire was administered to each mother to inquire about their habits and food consumption during the first trimester of pregnancy.

RESULTS

Folic acid supplementation was observed in 116 (87.8%) of the case group (p < 0.001) and 271 (97.8%) of the control group. Regarding the use of ferrous sulfate, 114 (86.3%) of the case group and 271 (97.8%) of the control group reported using it. In the case group, 84 (63.6%) mothers reported being exposed to second-hand smoke, and 5 (3.7%) reported alcohol consumption (p = 0.797). In terms of caffeine consumption, 127 mothers (95.4%) in the case group consumed it (p = 0.13), while 247 (88.8%) reported consumption in the control group.

CONCLUSIONS

The results suggest a direct relationship between secondhand smoke, alcohol consumption, and the lack of maternal supplementation with oral clefts.

The impact of an online educational program to reduce second-hand exposure to smoke among nonsmoking pregnant women; a hospital-based intervention study

Background

Second-hand smoke is recognized as a public health concern, especially for pregnant women.

Objectives

To compare pregnant women's exposure and perceptions of SHS pre-and post-intervention.

Materials and methods

The study was conducted with a sample of 32 pregnant women at a tertiary university hospital in Jordan. Using a semi-structured questionnaire, researchers asked women about their knowledge, attitude and behavior regarding prenatal exposure to smoke before and after an intervention that included motivation, communication, education and counselling by using a range of media. A cotinine test was conducted to measure levels in second-hand smokers.

Results

The average maternal age was 30.88 ± 1.69 years; 68% were highly educated, 43% were employed, 37% reported not having sufficient income, and 62% did not attend for antenatal care on a regular basis. There was a significant increase in knowledge and awareness regarding second-hand smoking and its effect on pregnancy outcomes after the intervention. More than 90% of pregnant women supported a comprehensive policy in relation to smoking, and 33% of used to leave the room where others smoked. This percentage increased to 70% after the intervention. Cotinine level decreased after the intervention in 81% of cases.

Conclusions

There is an increase in knowledge and awareness regarding second-hand smoking and its effects on pregnancy outcomes after implementation of an educational intervention.

Relationships between Women's and Men's Modifiable Preconception Risks and Health Behaviors and Maternal and Offspring Health Outcomes: An Umbrella Review

Parental health before conception effects maternal and offspring health outcomes. Preconception care provides healthcare to prospective parents addressing modifiable preconception risks and health behaviors. This umbrella review aimed to consolidate evidence on women's and men's modifiable preconception risks or health behaviors associated with maternal and offspring health outcomes. MEDLINE, EMBASE, Maternity and Infant Care, CINAHL, and PsycINFO were searched from March 4, 2010, to March 4, 2020. Eligible studies were systematic reviews or meta-analyses of observational studies examining associations between modifiable preconception risks or health behaviors and maternal and offspring health outcomes. Screening, data extraction, and methodological quality assessment (AMSTAR 2) occurred independently by two reviewers. Degree of overlap was examined. Findings were summarized for evidence synthesis. Twenty-seven systematic reviews were included. Modifiable preconception risks and health behaviors were identified across categories: body composition (e.g., overweight, obesity), lifestyle behaviors (e.g., caffeine, smoking), nutrition (e.g., micronutrients), environmental exposures (e.g., radiation), and birth spacing (e.g., short interpregnancy intervals). Outcomes associated with exposures affected embryo (e.g., embryonic growth), maternal (e.g., gestational diabetes mellitus), fetal/neonate (e.g., preterm birth), and child (e.g., neurocognitive disorders) health. For real-world practice and policy relevance, evidence-based indicators for preconception care should include body composition, lifestyle, nutrition, environmental, and birth spacing.

Propensity score analysis of the association between maternal exposure to second-hand tobacco smoke and birth defects in Northwestern China

Previous studies have suggested that maternal active smoking can increase the risk of birth defects, but evidence on second-hand tobacco smoke (SHS) is limited. We aimed to assess the association between maternal exposure to SHS and birth defects in a Chinese population. The data were based on a large-scale cross-sectional survey conducted in Shaanxi Province, China. Considering the characteristics of survey design and the potential impact of confounding factors, we adopted propensity score matching (PSM) to match the SHS exposure group and the non-exposure group to attain a balance of the confounders between the two groups. Subsequently, conditional logistic regression was employed to estimate the effect of SHS exposure on birth defects. Furthermore, sensitivity analyses were conducted to verify the key findings. After nearest neighbor matching of PSM with a ratio of 2 and a caliper width of 0.03, there were 6,205 and 12,410 participants in the exposure and control group, respectively. Pregnant women exposed to SHS were estimated to be 58% more likely to have infants with overall birth defects (OR = 1.58, 95% CI: 1.30-1.91) and 75% more likely to have infants with circulatory system defects (OR = 1.75, 95% CI: 1.26-2.44). We also observed that the risk effect of overall birth defects had an increasing trend as the frequency of exposure increased. Additionally, sensitivity analyses suggested that our results had good robustness. These results indicate that maternal exposure to SHS likely increases the risk of overall birth defects, especially circulatory system defects, in Chinese offspring.

The impact of changing cigarette smoking habits and smoke-free legislation on orofacial cleft incidence in the United Kingdom: Evidence from two time-series studies

BACKGROUND

Both active and passive cigarette smoking have previously been associated with orofacial cleft aetiology. We aimed to analyse the impact of declining active smoking prevalence and the implementation of smoke-free legislation on the incidence of children born with a cleft lip and/or palate within the United Kingdom.

METHODS AND FINDINGS

We conducted regression analysis using national administrative data in the United Kingdom between 2000-2018. The main outcome measure was orofacial cleft incidence, reported annually for England, Wales and Northern Ireland and separately for Scotland. First, we conducted an ecological study with longitudinal time-series analysis using smoking prevalence data for females over 16 years of age. Second, we used a natural experiment design with interrupted time-series analysis to assess the impact of smoke-free legislation. Over the study period, the annual incidence of orofacial cleft per 10,000 live births ranged from 14.2-16.2 in England, Wales and Northern Ireland and 13.4-18.8 in Scotland. The proportion of active smokers amongst females in the United Kingdom declined by 37% during the study period. Adjusted regression analysis did not show a correlation between the proportion of active smokers and orofacial cleft incidence in either dataset, although we were unable to exclude a modest effect of the magnitude seen in individual-level observational studies. The data in England, Wales and Northern Ireland suggested an 8% reduction in orofacial cleft incidence (RR 0.92, 95%CI 0.85 to 0.99; P = 0.024) following the implementation of smoke-free legislation. In Scotland, there was weak evidence for an increase in orofacial cleft incidence following smoke-free legislation (RR 1.16, 95%CI 0.94 to 1.44; P = 0.173).

CONCLUSIONS

These two ecological studies offer a novel insight into the influence of smoking in orofacial cleft aetiology, adding to the evidence base from individual-level studies. Our results suggest that smoke-free legislation may have reduced orofacial cleft incidence in England, Wales and Northern Ireland.

Environmental and Genetic Risk Factors of Congenital Anomalies: an Umbrella Review of Systematic Reviews and Meta-Analyses

BACKGROUND

The prevalence of congenital anomalies in newborns in South Korea was 272.9 per 100,000 in 2005, and 314.7 per 100,000 in 2006. In other studies, the prevalence of congenital anomalies in South Korea was equivalent to 286.9 per 10,000 livebirths in 2006, while it was estimated 446.3 per 10,000 births during the period from 2008 to 2014. Several systematic reviews and meta-analyses analyzing the factors contributing to congenital anomalies have been reported, but comprehensive umbrella reviews are lacking.

METHODS

We searched PubMed, Google Scholar, Cochrane, and EMBASE databases up to July 1, 2019, for systematic reviews and meta-analyses that investigated the effects of environmental and genetic factors on any type of congenital anomalies. We categorized 8 subgroups of congenital anomalies classified according to the 10th revision of the International Statistical Classification of Diseases (ICD-10). Two researchers independently searched the literature, retrieved the data, and evaluated the quality of each study.

RESULTS

We reviewed 66 systematic reviews and meta-analyses that investigated the association between non-genetic or genetic risk factors and congenital anomalies. Overall, 269 associations and 128 associations were considered for environmental and genetic risk factors, respectively. Congenital anomalies based on congenital heart diseases, cleft lip and palate, and others were associated with environmental risk factors based on maternal exposure to environmental exposures (air pollution, toxic chemicals), parental smoking, maternal history (infectious diseases during pregnancy, pregestational and gestational diabetes mellitus, and gestational diabetes mellitus), maternal obesity, maternal drug intake, pregnancy through artificial reproductive technologies, and socioeconomic factors. The association of maternal alcohol or coffee consumption with congenital anomalies was not significant, and maternal folic acid supplementation had a preventive effect on congenital heart defects. Genes or genetic loci associated with congenital anomalies included MTHFR, MTRR and MTR, GATA4, NKX2-5, SRD5A2, CFTR, and 1p22 and 20q12 anomalies.

CONCLUSION

This study provides a wide perspective on the distribution of environmental and genetic risk factors of congenital anomalies, thus suggesting future studies and providing health policy implications.

Environmental Risk Factors and Congenital Heart Disease: An Umbrella Review of 165 Systematic Reviews and Meta-Analyses With More Than 120 Million Participants

Background: The etiology of congenital heart disease (CHD) has been extensively studied in the past decades. Therefore, it is critical to clarify clear hierarchies of evidence between types of environmental factors and CHD. Methods: Electronic searches in PubMed, Embase, Web of Science, Cochrane database were conducted from inception to April 20, 2020 for meta-analyses investigating the aforementioned topic. Results: Overall, 41 studies including a total of 165 meta-analyses of different environmental factors and CHD were examined, covering a wide range of risk factors. The summary random effects estimates were significant at P < 0.05 in 63 meta-analyses (38%), and 15 associations (9%) were significant at P < 10^-6. Of these meta-analyses, eventually one risk factor (severe obesity; relative risk: 1.38, 95% confidence interval: 1.30-1.47) had significant summary associations at P < 10^-6, included more than 1,000 cases, had 95% prediction intervals excluding the null value, and were not suggestive of large heterogeneity (I ² < 50%), small-study effects (P-value for Egger's test > 0.10), or excess significance (P > 0.10). Eight associations (5%) (including maternal lithium exposure, maternal obesity, maternal alcohol consumption, and maternal fever) had results that were significant at P < 10^-6, included more than 1,000 cases, and had 95% prediction intervals excluding the null value (highly suggestive). Conclusion: This umbrella review shows that many environmental factors have substantial evidence in relation to the risk of developing CHD. More and better-designed studies are needed to establish robust evidence between environmental factors and CHD. Systematic Review Registration: [PROSPERO], identifier [CRD42020193381].

AT1-receptor autoantibody exposure in utero contributes to cardiac dysfunction and increased glycolysis in fetal mice

Exposure to adverse factors in utero may lead to adaptive changes in cardiac structure and metabolism, which increases the risk of chronic cardiovascular disease later in life. Studies showed that the angiotensin II type 1 receptor autoantibodies (AT1-AAs) are able to cross the placenta into the circulation of pregnant rodents' embryo, which adversely affects embryogenesis. However, the effects of AT1-AA exposure on the fetal heart in utero are still unknown. In this study, we investigated whether intrauterine AT1-AA exposure has adverse effects on fetal heart structure, function and metabolism. AT1-AA-positive pregnant mouse models were successfully established by passive immunity, evidenced by increased AT1-AA content. Morphological and ultrasonic results showed that the fetal mice on embryonic day 18 (E18) of AT1-AA group have loose and disordered myocardial structure, and decreased left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS), compared with control groups. The myocardium of AT1-AA group fetal mice on E18 exhibited increased expression of the key molecules in the glycolytic pathway, pyruvate and lactic acid content and ATP production, suggesting that the glycolysis rate was enhanced. Furthermore, the enhanced effect of glycolysis caused by AT1-AA is mainly through the PPARβ/δ pathway. These data confirmed that fetus exposure to AT1-AA in utero developed left ventricular dysfunction, myocardial structural arrangement disorders, and enhanced glycolysis on E18. Our results support AT1-AA being a potentially harmful factor for cardiovascular disease in fetal mice.

Environmental mechanisms of orofacial clefts

Orofacial clefts (OFCs) are among the most common birth defects and impart a significant burden on afflicted individuals and their families. It is increasingly understood that many nonsyndromic OFCs are a consequence of extrinsic factors, genetic susceptibilities, and interactions of the two. Therefore, understanding the environmental mechanisms of OFCs is important in the prevention of future cases. This review examines the molecular mechanisms associated with environmental factors that either protect against or increase the risk of OFCs. We focus on essential metabolic pathways, environmental signaling mechanisms, detoxification pathways, behavioral risk factors, and biological hazards that may disrupt orofacial development.

Influence of family resources on secondhand smoking in pregnant women: a cross-sectional study in the border and minority urban areas of Northwest China

BACKGROUND

Pregnant women's exposure to secondhand smoke is a very serious health issue in China. The purpose of our research is to identify factors that predict the probability of exposure to secondhand smoke among pregnant women from the perspective of a family-based open system.

METHODS

From September 2014 to August 2015, Urumqi City, Shihezi City, and Shawan County-level City were sampled according to population characteristics. A revised structured questionnaire based on family resources was adapted for use in this study. Questionnaires were collected via convenience sampling at the hospitals with the largest number of local antenatal clients. A total of 1249 pregnant women of age 18-51 years were investigated. Descriptive statistics were calculated to characterize the participants and study variables. Binary logistic regression was performed to assess the impact of family resources corresponding variables on the likelihood that participants would be exposed to SHS. Both unadjusted and adjusted odds ratios (OR/AOR) [with 95% confidence intervals (CI)] were reported.

RESULTS

The secondhand smoke exposure rate found in this study was 54.6%. Having good knowledge of the dangers of secondhand smoke had no effect on reducing the prevalence of exposure (P > 0.05). Even pregnant women whose husbands who did not use tobacco or never smoked nearby had a risk of exposure to secondhand smoke [adjusted odds ratio (AOR) 1.568, 95% CI 1.205-2.041] when the data were adjusted for age, gravidity, gestational weeks, knowledge of the dangers of secondhand smoke, location, and work status. Home smoking bans were confirmed to be an important protective factor (AOR 1.710, 95% CI 1.549-1.918); however, only one-third (33.5%) of participants reported having a smoking ban at home. Religion (mainly Islam), as a special external family resource, was a protective factor that reduced secondhand smoke exposure in pregnant women (AOR 0.399, 95% CI 0.312-0.510).

CONCLUSIONS

The effect of family resources on tobacco control should be considered in the development of effective and enduring strategies for indoor smoking bans and smoking cessation.

Current Resources for Evidence-Based Practice, July 2020

An extensive review of new resources to support the provision of evidence-based care for women and infants. The current column includes a discussion of whether it is ethical not to offer doula care to all women, and commentaries on reviews focused on folic acid and autism spectrum disorder, and timing of influenza vaccination during pregnancy.