Swimming pool use and birth defect risk

Nongenetic risk factors for infantile cataracts: Systematic review of observational studies

INTRODUCTION

While infantile cataracts are a major cause of childhood blindness, risk factors remain unknown for approximately two-thirds of cases.

METHODS

We systematically searched electronic databases PubMed, Ovid MEDLINE, Web of Science, and Scopus, from inception through March 2018, to identify relevant cohort, case-control, cross-sectional studies, case reports, and case series. We also manually screened bibliographies and consulted with experts in the field to identify additional publications. We reviewed cross-sectional studies, case reports, and case series and provided a narrative summary of the reported potential risk factors. We evaluated methodological qualities of cohort and case-control studies, extracted relevant data, and described statistically significant associations with infant, maternal, and paternal characteristics. Quality assessment and data extraction were conducted by two reviewers independently. All discrepancies were discussed with the senior author and resolved by consensus.

RESULTS

Overall, 110 publications were included in the review, 33 of which were cohort and case-control studies. Most of these studies (n = 32) used population-based data and had either excellent (n = 31) or good (n = 2) methodological quality. Nine studies reported statistically significant associations with infant characteristics (preterm birth, low birth weight), maternal occupations and diseases during pregnancy (untreated hypertension, infections), and paternal sociodemographics (younger age, employment in sawmill industry during pregnancy).

CONCLUSIONS

This systematic literature review provided a comprehensive summary of the known nongenetic risk factors for infantile cataracts, identified gaps in the literature, and provided directions for future research. Studies identifying modifiable risk factors are warranted to design interventions aimed at primary prevention of infantile cataracts.

Application of diversified and quantitative management model of exercise intervention in patients with gestational diabetes mellitus

Objective: The study aims to explore the application of diversified and quantitative management model of exercise intervention in patients with gestational diabetes mellitus (GDM). Methods: From January 2018 to July 2018, 150 pregnant women with GDM were recruited from HangZhou Maternity Hospital, and were randomly divided into control group (n = 75) and experimental group (n = 75). All patients were registered pregnancy exercise self-efficacy scale (P-ESES), fasting blood glucose (FBG), and 2-hour postpranational blood glucose (2hPG). Patients in control group received conventional sports, while patients in experimental group added multiple quantitative exercise intervention management mode until delivery (accumulated at least 30 min per day, the time of not less than 150 min per week). After 4 weeks of intervention, patients in both groups were measured P-ESES, FBG, and 2hPG levels. Results: A total of 12 patients dropped out of the study, was lost to follow-up or was admitted to another hospital; therefore, 138 cases (68 vs. 70) were included in analysis. There was no significant difference of P-ESES, FBG, and 2hPG of patients in baseline. After four weeks intervention, compared with the control group, the P-ESES score was significantly increased (p<.05), the overcoming movement disorder, overcoming emotional disorder, and overcoming support disorder scores were significantly improved (p<.05), and the levels of FBG and 2hPG were significantly decreased (p<.05) in experimental group. Finally, the coincidence rate of weight gain during pregnancy was increased, the rate of macrosomia delivery and cesarean section were decreased in experimental group (p<.05). Conclusion: Quantitative management model of multiform exercise therapy improved patients with GDM.

Lifestyle and sociodemographic risk factors for gastroschisis: a systematic review and meta-analysis

BACKGROUND

Gastroschisis is strongly associated with young maternal age. This association suggests the need for further investigations on non-genetic risk factors. Identifying these risk factors is a public health priority in order to develop prevention strategies aimed at reducing the prevalence and health consequences in offspring.

OBJECTIVE

To systematically assess and quantitatively synthesise the available epidemiological studies to evaluate the association between non-genetic risk factors and gastroschisis.

METHODS

Literature from PubMed, EMBASE and Scopus was searched for the period 1990-2018. Epidemiological studies reporting risk estimates between lifestyle and sociodemographic risk factors and gastroschisis were included. Two pairs of reviewers independently extracted information on study characteristics following Preferred Reporting Items for Systematic Reviews and Meta-Analyses and MOOSE (Meta-analysis Of Oservational Studies in Epidemiology) guidelines. Relative risk (RR) estimates were calculated across the studies and meta-analysis was performed using random-effects model.

RESULTS

We identified 58 studies. Meta-analyses were conducted on 29 studies. Maternal smoking (RR 1.56, 95% CI 1.40 to 1.74), illicit drug use (RR 2.14, 95% CI 1.48 to 3.07) and alcohol consumption (RR 1.40, 95% CI 1.13 to 1.70) were associated with an increased risk of gastroschisis. A decreased risk among black mothers compared with non-Hispanic white mothers (RR 0.49, 95% CI 0.38 to 0.63) was found. For Hispanic mothers no association was observed.

CONCLUSIONS

Exposure to smoking, illicit drugs and alcohol during pregnancy is associated with an increased risk of gastroschisis. A significantly decreased risk for black mothers was observed. Further epidemiological studies to assess the potential role of other environmental factors are strongly recommended.

PROSPERO REGISTRATION NUMBER

CRD42018104284.

Maternal swimming pool exposure during pregnancy in relation to birth outcomes and cord blood DNA methylation among private well users

Swimming in pools during pregnancy may expose the fetus to water disinfection by-products (DBP). As yet, our understanding of the impacts on DBPs on the fetus is uncertain. Individuals with public water systems are typically exposed to DBPs through drinking, showering and bathing, whereas among those on private water systems, swimming in pools may be the primary exposure source. We analyzed the effects of maternal swimming on birth outcomes and cord blood epigenetic changes in the New Hampshire Birth Cohort Study, a cohort of pregnant women with households on private water systems. Information about swimming in pools during pregnancy was obtained from 1033 women via questionnaires. Swimming pool use and duration were modeled using linear regression with newborn weight, length, and head circumference (z-scores) and genome wide cord blood DNA methylation as the outcomes and with adjustment for potential confounders. Overall 19.7% of women reported swimming in a pool during pregnancy. Among swimmers, duration of swimming was inversely related to head circumference (-0.02 z-score per 10% increase in duration, P = 0.004). No associations were observed with birth weight, length or DNA methylation modifications. Our findings suggest swimming pool exposure may impact the developing fetus although longer-term studies are needed.

Brain Metabolism Alterations Induced by Pregnancy Swimming Decreases Neurological Impairments Following Neonatal Hypoxia-Ischemia in Very Immature Rats

Introduction: Prematurity, through brain injury and altered development is a major cause of neurological impairments and can result in motor, cognitive and behavioral deficits later in life. Presently, there are no well-established effective therapies for preterm brain injury and the search for new strategies is needed. Intra-uterine environment plays a decisive role in brain maturation and interventions using the gestational window have been shown to influence long-term health in the offspring. In this study, we investigated whether pregnancy swimming can prevent the neurochemical metabolic alterations and damage that result from postnatal hypoxic-ischemic brain injury (HI) in very immature rats.

Methods: Female pregnant Wistar rats were divided into swimming (SW) or sedentary (SE) groups. Following a period of adaptation before mating, swimming was performed during the entire gestation. At postnatal day (PND3), rat pups from SW and SE dams had right common carotid artery occluded, followed by systemic hypoxia. At PND4 (24 h after HI), the early neurochemical profile was measured by ¹H-magnetic resonance spectroscopy. Astrogliosis, apoptosis and neurotrophins protein expression were assessed in the cortex and hippocampus. From PND45, behavioral testing was performed. Diffusion tensor imaging and neurite orientation dispersion and density imaging were used to evaluate brain microstructure and the levels of proteins were quantified.

Results: Pregnancy swimming was able to prevent early metabolic changes induced by HI preserving the energetic balance, decreasing apoptotic cell death and astrogliosis as well as maintaining the levels of neurotrophins. At adult age, swimming preserved brain microstructure and improved the performance in the behavioral tests.

Conclusion: Our study points out that swimming during gestation in rats could prevent prematurity related brain damage in progeny with high translational potential and possibly interesting cost-benefits.

HIGHLIGHTS

- Prematurity is a major cause of neurodevelopmental impairments;

- Swimming during pregnancy reduces brain damage after HI injury;

- Pregnancy is an important but underestimated preventive window.

Occurrence and formation of disinfection by-products in the swimming pool environment: A critical review

Disinfection of water for human use is essential to protect against microbial disease; however, disinfection also leads to formation of disinfection by-products (DBPs), some of which are of health concern. From a chemical perspective, swimming pools are a complex matrix, with continual addition of a wide range of natural and anthropogenic chemicals via filling waters, disinfectant addition, pharmaceuticals and personal care products and human body excretions. Natural organic matter, trace amounts of DBPs and chlorine or chloramines may be introduced by the filling water, which is commonly disinfected distributed drinking water. Chlorine and/or bromine is continually introduced via the addition of chemical disinfectants to the pool. Human body excretions (sweat, urine and saliva) and pharmaceuticals and personal care products (sunscreens, cosmetics, hair products and lotions) are introduced by swimmers. High addition of disinfectant leads to a high formation of DBPs from reaction of some of the chemicals with the disinfectant. Swimming pool air is also of concern as volatile DBPs partition into the air above the pool. The presence of bromine leads to the formation of a wide range of bromo- and bromo/chloro-DBPs, and Br-DBPs are more toxic than their chlorinated analogues. This is particularly important for seawater-filled pools or pools using a bromine-based disinfectant. This review summarises chemical contaminants and DBPs in swimming pool waters, as well as in the air above pools. Factors that have been found to affect DBP formation in pools are discussed. The impact of the swimming pool environment on human health is reviewed.

The green tea polyphenol EGCG alleviates maternal diabetes-induced neural tube defects by inhibiting DNA hypermethylation

BACKGROUND

Maternal diabetes increases the risk of neural tube defects in offspring. Our previous study demonstrated that the green tea polyphenol, Epigallocatechin gallate, inhibits high glucose-induced neural tube defects in cultured embryos. However, the therapeutic effect of Epigallocatechin gallate on maternal diabetes-induced neural tube defects is still unclear.

OBJECTIVE

We aimed to examine whether Epigallocatechin gallate treatment can reduce maternal diabetes-induced DNA methylation and neural tube defects.

STUDY DESIGN

Nondiabetic and diabetic pregnant mice at embryonic day 5.5 were given drinking water with or without 1 or 10 μM Epigallocatechin gallate. At embryonic day 8.75, embryos were dissected from the visceral yolk sac for the measurement of the levels and activity of DNA methyltransferases, the levels of global DNA methylation, and methylation in the CpG islands of neural tube closure essential gene promoters. embryonic day 10.5 embryos were examined for neural tube defect incidence.

RESULTS

Epigallocatechin gallate treatment did not affect embryonic development because embryos from nondiabetic dams treated with Epigallocatechin gallate did not exhibit any neural tube defects. Treatment with 1 μM Epigallocatechin gallate did not reduce maternal diabetes-induced neural tube defects significantly. Embryos from diabetic dams treated with 10 μM Epigallocatechin gallate had a significantly lower neural tube defect incidence compared with that of embryos without Epigallocatechin gallate treatment. Epigallocatechin gallate reduced neural tube defect rates from 29.5% to 2%, an incidence that is comparable with that of embryos from nondiabetic dams. Ten micromoles of Epigallocatechin gallate treatment blocked maternal diabetes-increased DNA methyltransferases 3a and 3b expression and their activities, leading to the suppression of global DNA hypermethylation. Additionally, 10 μM Epigallocatechin gallate abrogated maternal diabetes-increased DNA methylation in the CpG islands of neural tube closure essential genes, including Grhl3, Pax3, and Tulp3.

CONCLUSION

Epigallocatechin gallate reduces maternal diabetes-induced neural tube defects formation and blocks the enhanced expression and activity of DNA methyltransferases, leading to the suppression of DNA hypermethylation and the restoration of neural tube closure essential gene expression. These observations suggest that Epigallocatechin gallate supplements could mitigate the teratogenic effects of hyperglycemia on the developing embryo and prevent diabetes-induced neural tube defects.

Type 2 diabetes mellitus induces congenital heart defects in murine embryos by increasing oxidative stress, endoplasmic reticulum stress, and apoptosis

BACKGROUND

Maternal type 1 and 2 diabetes mellitus are strongly associated with high rates of severe structural birth defects, including congenital heart defects. Studies in type 1 diabetic embryopathy animal models have demonstrated that cellular stress-induced apoptosis mediates the teratogenicity of maternal diabetes leading to congenital heart defect formation. However, the mechanisms underlying maternal type 2 diabetes mellitus-induced congenital heart defects remain largely unknown.

OBJECTIVE

We aim to determine whether oxidative stress, endoplasmic reticulum stress, and excessive apoptosis are the intracellular molecular mechanisms underlying maternal type 2 diabetes mellitus-induced congenital heart defects.

STUDY DESIGN

A mouse model of maternal type 2 diabetes mellitus was established by feeding female mice a high-fat diet (60% fat). After 15 weeks on the high-fat diet, the mice showed characteristics of maternal type 2 diabetes mellitus. Control dams were either fed a normal diet (10% fat) or the high-fat diet during pregnancy only. Female mice from the high-fat diet group and the 2 control groups were mated with male mice that were fed a normal diet. At E12.5, embryonic hearts were harvested to determine the levels of lipid peroxides and superoxide, endoplasmic reticulum stress markers, cleaved caspase 3 and 8, and apoptosis. E17.5 embryonic hearts were harvested for the detection of congenital heart defect formation using India ink vessel patterning and histological examination.

RESULTS

Maternal type 2 diabetes mellitus significantly induced ventricular septal defects and persistent truncus arteriosus in the developing heart, along with increasing oxidative stress markers, including superoxide and lipid peroxidation; endoplasmic reticulum stress markers, including protein levels of phosphorylated-protein kinase RNA-like endoplasmic reticulum kinase, phosphorylated-IRE1α, phosphorylated-eIF2α, C/EBP homologous protein, and binding immunoglobulin protein; endoplasmic reticulum chaperone gene expression; and XBP1 messenger RNA splicing, as well as increased cleaved caspase 3 and 8 in embryonic hearts. Furthermore, maternal type 2 diabetes mellitus triggered excessive apoptosis in ventricular myocardium, endocardial cushion, and outflow tract of the embryonic heart.

CONCLUSION

Similar to those observations in type 1 diabetic embryopathy, maternal type 2 diabetes mellitus causes heart defects in the developing embryo manifested with oxidative stress, endoplasmic reticulum stress, and excessive apoptosis in heart cells.

Genetic and nongenetic etiology of nonsyndromic anorectal malformations: a systematic review

Congenital anorectal malformations (ARMs) are one of the most frequently observed birth defects of the digestive system. However, their etiology remains elusive. Therefore, we aim to summarize and critically appraise all existing literature on the genetic and nongenetic etiology of nonsyndromic ARM and to conclude with unifying hypotheses and directions for future research. A structured literature search on English language human studies was conducted in PubMed and Embase up to October 1, 2013, resulting in 112 included articles. Research on the identification of genes underlying nonsyndromic ARM is remarkably scarce. Most studies were focused on screening of candidate genes for mutations or single-nucleotide polymorphisms, which did not yield any substantial evidence. Nongenetic factors fairly consistently found to be associated with ARM are assisted reproductive techniques, multiple pregnancy, preterm delivery, low birth weight, maternal overweight or obesity, and preexisting diabetes. This review provides indications for the involvement of both genes and nongenetic risk factors in the etiology of ARM. In future studies, large cohorts of patients with ARM from national and international collaborations are needed to acquire new hypotheses and knowledge through hypothesis-generating approaches. Challenges for future studies may also lie in the investigation of gene-gene and gene-environment interactions.