Congenital heart defects after maternal fever

The Legacy of the COVID-19 Pandemic: Impact on Infant and Maternal and Health from an Appalachian Academic Medical Center

BACKGROUND/OBJECTIVES

The COVID-19 pandemic period from 2020 to 2022 had a significant impact on maternal infant health with mothers impacted more than their infants. We questioned whether there have been any lingering effects from the pandemic.

METHODS

We examined intermediate and long-term pandemic effects on maternal and neonatal outcomes before, during, and after the COVID-19 pandemic period. We reviewed mother-infant pairs from the following three epochs: (1) the pre-COVID-19 period, (2) the COVID-19 pandemic period, and (3) the post-pandemic period. The Case Mix Index (CMI) for the neonates from all three epochs were detailed.

RESULTS

Post-pandemic, we noted a rising trend of LGA infants (10%) and an increase in SGA infants (13%). For women in 2023, we noted an increase in hypertension, preeclampsia, diabetes, and a higher BMI than in the pre-pandemic period. There have also been more congenital anomalies (9%), and neonatal CMI increased in the post-pandemic period.

CONCLUSIONS

Well after the pandemic period, maternal-infant health continues to be affected. For women, the increase in hypertension and diabetes during pregnancy is concerning. For infants, being LGA or SGA may have long-term consequences. The post-pandemic increase in infants with congenital anomalies compared to the pre-pandemic era is an area that needs ongoing review.

Cell-free DNA in maternal blood and artificial intelligence: accurate prenatal detection of fetal congenital heart defects

BACKGROUND

DNA cytosine nucleotide methylation (epigenomics and epigenetics) is an important mechanism for controlling gene expression in cardiac development. Combined artificial intelligence and whole-genome epigenomic analysis of circulating cell-free DNA in maternal blood has the potential for the detection of fetal congenital heart defects.

OBJECTIVE

This study aimed to use genome-wide DNA cytosine methylation and artificial intelligence analyses of circulating cell-free DNA for the minimally invasive detection of fetal congenital heart defects.

STUDY DESIGN

In this prospective study, whole-genome cytosine nucleotide methylation analysis was performed on circulating cell-free DNA using the Illumina Infinium MethylationEPIC BeadChip array. Multiple artificial intelligence approaches were evaluated for the detection of congenital hearts. The Ingenuity Pathway Analysis program was used to identify gene pathways that were epigenetically altered and important in congenital heart defect pathogenesis to further elucidate the pathogenesis of isolated congenital heart defects.

RESULTS

There were 12 cases of isolated nonsyndromic congenital heart defects and 26 matched controls. A total of 5918 cytosine nucleotides involving 4976 genes had significantly altered methylation, that is, a P value of <.05 along with ≥5% whole-genome cytosine nucleotide methylation difference, in congenital heart defect cases vs controls. Artificial intelligence analysis of the methylation data achieved excellent congenital heart defect predictive accuracy (areas under the receiver operating characteristic curve, ≥0.92). For example, an artificial intelligence model using a combination of 5 whole-genome cytosine nucleotide markers achieved an area under the receiver operating characteristic curve of 0.97 (95% confidence interval, 0.87-1.0) with 98% sensitivity and 94% specificity. We found epigenetic changes in genes and gene pathways involved in the following important cardiac developmental processes: "cardiovascular system development and function," "cardiac hypertrophy," "congenital heart anomaly," and "cardiovascular disease." This lends biologic plausibility to our findings.

CONCLUSION

This study reported the feasibility of minimally invasive detection of fetal congenital heart defect using artificial intelligence and DNA methylation analysis of circulating cell-free DNA for the prediction of fetal congenital heart defect. Furthermore, the findings supported an important role of epigenetic changes in congenital heart defect development.

Associations between maternal reports of periconceptional fever from miscellaneous causes and structural birth defects

BACKGROUND

Associations between birth defects and fevers attributed to colds, influenza, and urinary tract infections (UTIs) have been observed in previous studies. Our aim was to study associations between birth defects and fevers attributed to other causes.

METHODS

We analyzed data from 34,862 participants in the National Birth Defects Prevention Study, a multistate case-control study of major structural birth defects. Using multivariable logistic regression, we assessed the association between maternal report of fever during early pregnancy due to causes other than colds, influenza, or UTI and 36 categories of birth defects.

RESULTS

Maternal reports of fever due to other causes were associated with significantly elevated odds ratios ranging from 1.93 to 10.60 for 8 of 36 birth defects, primarily involving the spine, limbs, and heart (spina bifida, intestinal atresia, intercalary limb deficiency, transverse limb deficiency, congenital heart defect with heterotaxy, tetralogy of Fallot, pulmonary atresia and atrial septal defect, not otherwise specified).

CONCLUSION

Our data suggests fever itself or other physiologic changes associated with many infections are associated with some birth defects. Women who are pregnant or planning to become pregnant may want to consider speaking with their healthcare provider about the best ways to avoid infections that may cause fever and for guidance on how to treat fevers during pregnancy.

Possible Association of Pulmonary Atresia with In-Utero Coxsackievirus B Exposure

Gestational viral infection has been associated with congenital heart disease (CHD). Few studies, however, have studied the potential role of gestational Coxsackievirus B (CVB) exposure in the pathogenesis of CHD. We prospectively enrolled women with pregnancies affected by CHD to explore possible associations with in utero CVB exposure. Serum samples were obtained from 122 women referred for fetal echocardiography between 2006 and 2018. We quantified CVB IgG and IgM levels, with titers ≥ 15.0 U/mL considered positive and measured neutralizing antibodies for three CVB serotypes: CVB1, CVB3, and CVB4. Using data from the national enterovirus surveillance system, we compared the annual exposure rates for each serotype in our cohort to infections reported across the United States. 98 pregnancies with no genetic defects were included. Overall, 29.6% (29/98) had positive IgG and 4.1% (4/98) of women had positive CVB IgM titers. To explore first-trimester CVB exposure, we focused exclusively on the 26 women with positive IgG and negative IgM titers. 61.5% (16/26) had neutralizing antibodies against a single serotype and 38.5% (10/26) against multiple CVB serotypes. CVB4 neutralizing antibodies were the most common (65.4%, 17/26), followed by CVB3 (53.9%, 14/26) and CVB1 (30.8%, 8/26). Among these, 30.8% of babies presented pulmonary valve anomalies: 19.2% (5/26) pulmonary atresia, and 11.5% (3/26) pulmonary stenosis. 23.1% (6/26) of babies had coronary sinusoids. CVB exposure in our cohort mirrored that of reported infections in the United States. Our results suggest a possible association between gestational CVB exposure and specific CHD, particularly pulmonary valve anomalies and coronary sinusoids.

Evaluation of the usefulness of intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine in a context with increased resistance of Plasmodium falciparum in Kingasani Hospital, Kinshasa in the Democratic Republic of Congo

BACKGROUND

Increasing resistance of Plasmodium falciparum to sulfadoxine-pyrimethamine (SP) threatens its usefulness for intermittent preventive treatment in pregnancy (IPTp-SP). The prophylactic effects of IPTp-SP on maternal malaria and adverse pregnancy outcomes were evaluated in Kingasani Hospital, Kinshasa in the Democratic Republic of Congo (DRC).

METHODS

Laboring women (n = 844) and respective newborns were investigated. Blood samples collected from women were tested for malaria using rapid diagnostic test (RDT), blood smears examination, and real-time PCR. The hemoglobin level was measured by HemoCue© analyzer. A PCR-RFLP method was applied for detecting N51I, C59R, and S108N mutations on dhfr along with A437G and K540E mutations on dhps in P. falciparum positive samples. Logistic regression models assessed relationships between IPTp-SP uptake and pregnancy outcomes.

RESULTS

P. falciparum malaria was detected at delivery in 10.8% of women and was statistically associated with fever during the pregnancy (OR = 2.9 [1.5; 6.3]; p = 0.004) and maternal anemia (OR = 3.9 [2.4; 6.3]; p < 0.001). One out of five parasites was a quintuple mutant encoding dhfr mutations 51I, 59R, and 108 N along with dhps mutations 437G and 540E. The molecular profile of parasites (i.e., 32.6% of parasites carrying dhps K540E) was suitable with continued use of SP for IPTp. IPTp-SP uptake was not associated with reduced maternal malaria, fever reported in pregnancy, or fetal deaths (p > 0.05). Conversely, three or more doses of SP were associated with reduced maternal anemia at delivery (OR = 0.4 [0.2; 0.9]; p = 0.024), shortened gestation (OR = 0.4 [0.2; 0.8]; p = 0.009), and low-birth weights (OR = 0.2 [0.1; 0.5]; p < 0.001).

CONCLUSION

IPTp-SP was not associated with reduced maternal malaria in our study, but evidence was found of a prophylactic effect against adverse pregnancy outcomes. To counteract further loss of clinical effects of IPTp-SP in the study population, alternative strategies able to improve its anti-malarial efficacy such as combination of SP with partner molecules should be implemented.

Maternal fever during preconception and conception is associated with congenital heart diseases in offspring: An updated meta-analysis of observational studies

BACKGROUNDS

Many studies have evaluated the effect of maternal fever on the development risk of congenital heart diseases (CHDs) in offspring, but the findings were inconsistent. Furthermore, a complete overview of the existing data was also missing. Therefore, we intend to provide updated epidemiologic evidence to estimate the association between maternal fever and the risk of overall CHDs and specific CHD phenotypes in offspring.

METHODS

Pubmed, Embase, and Web of Science were searched through March 2020 to identify eligible studies that assessed the association between maternal fever and CHDs risk in offspring. The summary risk estimates were calculated using random-effects models. Potential heterogeneity source was explored by subgroup analyses and potential publication bias was assessed by Begg funnel plots and Begg rank correlation test.

RESULTS

Sixteen studies involving 31,922 CHDs cases among 183,563 participants were included in this meta-analysis. Overall, mothers who had a fever experience during preconception and conception periods had a significantly higher risk of overall CHDs in offspring (odds ratio [OR] = 1.45, 95% confidence interval [CI]: 1.21-1.73) when compared with those who did not have a fever experience. For specific CHD phenotypes in offspring, a statistically significant association was found between maternal fever and risk of conotruncal defects (CTD) (OR = 1.38, 95%CI: 1.01-1.89), atrial septal defects (ASD) (OR = 1.48, 95% CI: 1.01-2.17), transposition of the great vessels (TGA) (OR = 1.81, 95% CI: 1.14-2.88), and right ventricular outflow tract obstruction (RVOTO) (OR = 1.66, 95% CI: 1.04-2.65). Relevant heterogeneity moderators have been identified by subgroup analyses, and sensitivity analyses yielded consistent results.

CONCLUSIONS

Although the role of potential bias and evidence of heterogeneity should be carefully evaluated, our review indicates that maternal fever is significantly associated with the risk of CHDs in offspring, which highlights that preventing maternal fever during the preconception and conception periods play an important role in decreasing the risk of CHDs in offspring. However, given the limited number of current case-control studies, larger-sample prospective studies are required to further confirm our results. Besides, due to the underlying mechanisms between maternal fever and the risk of specific CHD phenotypes in offspring are still unreported, more research is needed to explore the possible mechanisms.

Capsaicin-Sensitive Sensory Nerves and the TRPV1 Ion Channel in Cardiac Physiology and Pathologies

Cardiovascular diseases, including coronary artery disease, ischemic heart diseases such as acute myocardial infarction and postischemic heart failure, heart failure of other etiologies, and cardiac arrhythmias, belong to the leading causes of death. Activation of capsaicin-sensitive sensory nerves by the transient receptor potential vanilloid 1 (TRPV1) capsaicin receptor and other receptors, as well as neuropeptide mediators released from them upon stimulation, play important physiological regulatory roles. Capsaicin-sensitive sensory nerves also contribute to the development and progression of some cardiac diseases, as well as to mechanisms of endogenous stress adaptation leading to cardioprotection. In this review, we summarize the role of capsaicin-sensitive afferents and the TRPV1 ion channel in physiological and pathophysiological functions of the heart based mainly on experimental results and show their diagnostic or therapeutic potentials. Although the actions of several other channels or receptors expressed on cardiac sensory afferents and the effects of TRPV1 channel activation on different non-neural cell types in the heart are not precisely known, most data suggest that stimulation of the TRPV1-expressing sensory nerves or stimulation/overexpression of TRPV1 channels have beneficial effects in cardiac diseases.

Incidence and mortality trend of congenital heart disease at the global, regional, and national level, 1990-2017

Congenital heart disease (CHD) is the most commonly diagnosed congenital disorder in newborns. The incidence and mortality of CHD vary worldwide. A detailed understanding of the global, regional, and national distribution of CHD is critical for CHD prevention.We collected the incidence and mortality data of CHD from the Global Burden of Disease study 2017 database. Average annual percentage change was applied to quantify the temporal trends of CHD incidence and mortality at the global, regional, and national level, 1990-2017. A sociodemographic index (SDI) was created for each location based on income per capita, educational attainment, and fertility.The incidence of CHD was relatively high in developing countries located in Africa and Asia, while low in most developed countries. Between 1990 and 2017, the CHD incidence rate remained stable at the global level, whereas increased in certain developed countries, such as Germany and France. The age-standardized mortality rate of CHD declined substantially over the last 3 decades, regardless of sex, age, and SDI region. The decline was more prominent in developed countries. We also detected a significant positive correlation between CHD incidence and CHD mortality in both 1990 and 2017, by SDI.The incidence of CHD remained stable over the last 3 decades, suggesting little improvement in CHD prevention strategies and highlighting the importance of etiological studies. The mortality of CHD decreased worldwide, albeit the greatly geographical heterogeneity. Developing countries located in Africa and Asia deserve more attention and priority in the global CHD prevention program.

The role of teratogens in neural crest development

The neural crest (NC), discovered by Wilhelm His 150 years ago, gives rise to a multipotent migratory embryonic cell population that generates a remarkably diverse and important array of cell types during the development of the vertebrate embryo. These cells originate in the neural plate border (NPB), which is the ectoderm between the neural plate and the epidermis. They give rise to the neurons and glia of the peripheral nervous system, melanocytes, chondrocytes, smooth muscle cells, odontoblasts and neuroendocrine cells, among others. Neurocristopathies are a class of congenital diseases resulting from the abnormal induction, specification, migration, differentiation or death of NC cells (NCCs) during embryonic development and have an important medical and societal impact. In general, congenital defects affect an appreciable percentage of newborns worldwide. Some of these defects are caused by teratogens, which are agents that negatively impact the formation of tissues and organs during development. In this review, we will discuss the teratogens linked to the development of many birth defects, with a strong focus on those that specifically affect the development of the NC, thereby producing neurocristopathies. Although increasing attention is being paid to the effect of teratogens on embryonic development in general, there is a strong need to critically evaluate the specific role of these agents in NC development. Therefore, increased understanding of the role of these factors in NC development will contribute to the planning of strategies aimed at the prevention and treatment of human neurocristopathies, whose etiology was previously not considered.

Parental smoking and the risk of congenital heart defects in offspring: An updated meta-analysis of observational studies

OBJECTIVE

Although previous reviews confirmed maternal active smoking was significantly associated with risk of fetal congenital heart defects (CHDs), association between maternal passive smoking and paternal smoking and risk of CHDs is inconclusive nowadays; furthermore, a complete overview is lacking. A meta-analysis of observational studies was conducted to assess the risk of CHDs associated with maternal active and passive smoking and paternal smoking.

METHODS

Seven electronic databases were searched for qualified research up to June 2018. We summarized study characteristics and the summary risk estimates were calculated using either the random-effect model or fixed-effect model. Sensitivity and subgroup analysis were carried out to identify the potential heterogeneity moderators.

RESULTS

One hundred and twenty-five studies involving 137,574 CHDs cases in 8,770,837 study participants were included. Overall, maternal active (risk ratio (RR) = 1.25; 95% confidence interval (CI): 1.16-1.34; p < 0.01) and passive (RR = 2.24, 95% CI: 1.81-2.77; p < 0.01) smoking as well as paternal active smoking (RR = 1.74, 95% CI: 1.48-2.06; p < 0.01) were significantly associated with CHDs risk. For specific CHD subtypes, our study showed that maternal active smoking was significantly associated with risk of atrial septal defect (RR = 1.27, 95% CI: 1.02-1.59; p = 0.03) and right ventricular outflow tract obstruction (RR = 1.43, 95% CI: 1.04-1.97; p = 0.03). Relevant heterogeneity moderators have been identified by subgroup analysis. Sensitivity analysis yielded consistent results.

CONCLUSION

Maternal active smoking, maternal passive smoking as well as paternal smoking all increased the risk of CHDs in offspring. Preventing parental smoking during peri-pregnancy is a priority for CHDs prevention.

A Matched Case-Control Study on the Association Between Colds, Depressive Symptoms during Pregnancy and Congenital Heart Disease in Northwestern China

The purpose of this study was to explore the association between colds, depressive symptoms during pregnancy and offspring congenital heart disease (CHD). A 1:2 matching case-control study was conducted in Northwest China. Information was gathered by a structured questionnaire and was reviewed by investigators on the spot. Multivariate logistic regressions and nonlinear mixed effect model were performed. 614 cases and 1228 controls were available in this study. After adjusting for potential confounders, the colds during the entire pregnancy were associated with increased risk of offspring CHD (OR = 1.44(1.12-1.85)). Similarly, there was a higher depression score in CHD group than the control group (OR = 1.89(1.48-2.41)). In addition, the women with both colds and higher depression scores had a higher risk of offspring CHD (OR = 2.72(1.87-3.93)) than their counterparts with only colds (OR = 1.48(1.04-2.09)) or with only higher depression scores (OR = 1.94(1.37-2.74)). The combined effects were significant in the multiplication model (OR = 2.04(1.47-2.83)) but not in the additive model (S = 1.40(0.70-2.81), AP = 0.19(-0.15-0.53) and RERI = 0.55(-0.54-1.64)). In conclusion, the colds and depressive symptoms during pregnancy were found associated with increased risk of offspring CHD and we found for the first time that there existed a statistically multiplying interaction effect of colds and depression on increasing risk of offspring CHD.

Prenatal inflammation exposure-programmed cardiovascular diseases and potential prevention

In recent years, the rapid development of medical and pharmacological interventions has led to a steady decline in certain noncommunicable chronic diseases (NCDs), such as cancer. However, the overall incidence of cardiovascular diseases (CVDs) has not seemed to decline. CVDs have become even more prevalent in many countries and represent a global health threat and financial burden. An increasing number of epidemiological and experimental studies have demonstrated that maternal insults not only can result in birth defects but also can cause developmental functional defects that contribute to adult NCDs. In the current review, we provide an overview of evidence from both epidemiological investigations and experimental animal studies supporting the concept of developmental reprogramming of adult CVDs in offspring that have experienced prenatal inflammation exposure (PIE) during fetal development (PIE-programmed CVDs), a disease-causing event that has not been effectively controlled. This review describes the epidemiological observations, data from animal models, and related mechanisms for the pathogenesis of PIE-programmed CVDs. In addition, the potential therapeutic interventions of PIE-programmed CVDs are discussed. Finally, we also deliberate the need for future mechanistic studies and biomarker screenings in this important field, which creates a great opportunity to combat the global increase in CVDs by managing the adverse effects of inflammation for prepregnant and pregnant individuals who are at risk for PIE-programmed CVDs.

Propensity Score-Matched Analysis on the Association Between Pregnancy Infections and Adverse Birth Outcomes in Rural Northwestern China

The purpose of this study is to examine the relationship between infections and birth outcomes in pregnant Chinese women by using propensity score (PS) matching. The data used here was from a large population-based cross-sectional epidemiological survey on birth defects in Shaanxi province, Northwest China. The babies born during 2010–2013 and their mothers were selected with a stratified multistage sampling method. We used PS-matched (1:1) analysis to match participants with infections to participants without infections. Of 22916 rural participants, the overall prevalence of infection was about 39.96%. 5381 pairs were matched. We observed increased risks of birth defects with infections, respiratory infections and genitourinary infections during the pregnancy (OR, 1.59; 95% CI: 1.21–2.08; OR, 1.44; 95% CI: 1.10–1.87; OR, 3.11; 95% CI: 1.75–5.54). There was also a significant increase of low birth weight associated with respiratory infections (1.13(1.01–1.27)). The association of birth defect with the infection could be relatively stable but the effect could be mediated by some important factors such as mother’s age, education level and economic level. The infection during pregnancy is common in Chinese women and might increase the risk of offspring birth defects and low birth weight, especially in younger, lower education, poor pregnant women.

Fever in pregnancy and the risk of congenital malformations: a cohort study

Background

In a variety of animal species, hyperthermia in pregnancy has been recognized as teratogenic. Hyperthermia interferes with protein synthesis via heat-shock proteins, which can entail membrane disruption, cell death, vascular disruption, and placental infarction. This can induce severe fetal malformations or death. Fever during pregnancy, especially during embryogenesis, has also been associated with congenital malformations in human offspring.

The purpose of this large cohort study of clinically recognized pregnancies was to investigate whether fever during first trimester was associated with an increased risk of congenital malformations in the offspring.

Methods

The Danish National Birth Cohort is a population-based cohort of 100,418 pregnant women and their offspring recruited in 1996 to 2002. Information on fever during pregnancy was collected prospectively by means of two telephone interviews.

The study population comprised the 77,344 pregnancies enrolled in the Danish National Birth Cohort where self-reported information on fever during first trimester of pregnancy was available. Pregnancy outcomes were identified through linkage with the National Patient Registry. Congenital malformations within the first three and a half years of life were categorized according to EUROCAT’s classification criteria. Logistic regression models were used to estimate the associations between fever in first trimester and overall congenital malformations and congenital malformations by subgroups.

Results

Eight thousand three hundred twenty-one women reported fever during first trimester (10.8%) and 2876 infants were diagnosed with a congenital malformation (3.7%). Fever during first trimester did not affect the risk of overall fetal congenital malformation (OR 0.99, 95% CI 0.88–1.12). The subgroup analyses indicated slightly higher risk of congenital anomalies in the eye, ear, face and neck (OR 1.29, 95% CI 0.78–2.12) and in the genitals (OR 1.17, 95% CI 0.79–1.12), whereas lower risk of malformations in the nervous system (OR 0.47, 95% CI 0.21–1.08), the respiratory system (OR 0.56, 95% CI 0.23–1.29) and in the urinary subgroup (OR 0.58, 95% CI 0.35–0.99) was suggested, the latter constituting the only statistically significant finding.

Conclusions

Overall, this study did not show any association between maternal fever in pregnancy and risk of congenital anomalies.

Maternal report of fever from cold or flu during early pregnancy and the risk for noncardiac birth defects, National Birth Defects Prevention Study, 1997-2011

BACKGROUND

As maternal fever affects approximately 6-8% of early pregnancies, it is important to expand upon previous observations of an association between maternal fever and birth defects.

METHODS

We analyzed data from the National Birth Defects Prevention Study, a multistate, case-control study of major structural birth defects. Telephone interviews were completed by mothers of cases (n = 17,162) and controls (n = 10,127). Using multivariable logistic regression, we assessed the association between maternal self-report of cold or flu with fever and cold or flu without fever during early pregnancy and 30 categories of non-cardiac birth defects.

RESULTS

Maternal report of cold or flu with fever was significantly associated with 8 birth defects (anencephaly, spina bifida, encephalocele, cleft lip with or without cleft palate, colonic atresia/stenosis, bilateral renal agenesis/hypoplasia, limb reduction defects, and gastroschisis) with elevated adjusted odds ratios ranging from 1.2 to 3.7. Maternal report of cold or flu without fever was not associated with any of the birth defects studied.

CONCLUSIONS

This study adds to the evidence that maternal fever during early pregnancy is associated with an increased risk for selected birth defects. Elevated associations were limited to mothers who reported a fever, suggesting that it is fever that contributes to the excess risk rather than illnesses associated with it. However, fever may also serve as a marker for more severe infections.

Temperature-activated ion channels in neural crest cells confer maternal fever-associated birth defects

Birth defects of the heart and face are common, and most have no known genetic cause, suggesting a role for environmental factors. Maternal fever during the first trimester is an environmental risk factor linked to these defects. Neural crest cells are precursor populations essential to the development of both at-risk tissues. We report that two heat-activated transient receptor potential (TRP) ion channels, TRPV1 and TRPV4, were present in neural crest cells during critical windows of heart and face development. TRPV1 antagonists protected against the development of hyperthermia-induced defects in chick embryos. Treatment with chemical agonists of TRPV1 or TRPV4 replicated hyperthermia-induced birth defects in chick and zebrafish embryos. To test whether transient TRPV channel permeability in neural crest cells was sufficient to induce these defects, we engineered iron-binding modifications to TRPV1 and TRPV4 that enabled remote and noninvasive activation of these channels in specific cellular locations and at specific developmental times in chick embryos with radio-frequency electromagnetic fields. Transient stimulation of radio frequency-controlled TRP channels in neural crest cells replicated fever-associated defects in developing chick embryos. Our data provide a previously undescribed mechanism for congenital defects, whereby hyperthermia activates ion channels that negatively affect fetal development.

Pregnancy-related conditions and premature coronary heart disease in adult offspring

Objective

To investigate the association between complications during pregnancy and premature coronary heart disease in adult offspring.

Methods

We conducted a population-based case-control study of 153 Indonesian patients with a first acute coronary syndrome (ACS) (age ≤55 years) and 153 age-matched and sex-matched controls. Data on complications during pregnancy (high blood pressure, preterm delivery) and maternal infections in pregnancy were obtained, together with sociodemographic data, clinical profiles, laboratory measurements and adulthood cardiovascular disease (CVD) risk factors at hospital admission or enrolment. Conditional logistic regression was performed to assess the association between overall pregnancy complications, and specific groupings of complications and premature ACS.

Results

Pregnancy-related hypertension and infection were more common in mothers of cases than controls. Pregnancy complications were associated with premature offspring ACS (OR 2.9, 95% CI 1.4 to 6.0, p=0.004), and the association persisted in fully adjusted analyses (OR_adjusted 4.5, 1.1 to 18.1, p=0.036). In subgroup analyses, pregnancy-related high blood pressure (OR_adjusted 5.0, 1.0 to 24.7, p=0.050) and maternal infections (OR_adjusted 5.2, 1.1 to 24.2, p=0.035) were associated with offspring ACS.

Conclusions

Offspring of mothers with complications during pregnancy have an increased risk for premature ACS in adulthood, which may be of particular relevance in populations in transition, where the incidence of both pregnancy-related morbidity and CVD are high.

The changing epidemiology of Ebstein's anomaly and its relationship with maternal mental health conditions: a European registry-based study

OBJECTIVES

The aim of this study was to describe the epidemiology of Ebstein's anomaly in Europe and its association with maternal health and medication exposure during pregnancy.

DESIGN

We carried out a descriptive epidemiological analysis of population-based data.

SETTING

We included data from 15 European Surveillance of Congenital Anomalies Congenital Anomaly Registries in 12 European countries, with a population of 5.6 million births during 1982-2011. Participants Cases included live births, fetal deaths from 20 weeks gestation, and terminations of pregnancy for fetal anomaly. Main outcome measures We estimated total prevalence per 10,000 births. Odds ratios for exposure to maternal illnesses/medications in the first trimester of pregnancy were calculated by comparing Ebstein's anomaly cases with cardiac and non-cardiac malformed controls, excluding cases with genetic syndromes and adjusting for time period and country.

RESULTS

In total, 264 Ebstein's anomaly cases were recorded; 81% were live births, 2% of which were diagnosed after the 1st year of life; 54% of cases with Ebstein's anomaly or a co-existing congenital anomaly were prenatally diagnosed. Total prevalence rose over time from 0.29 (95% confidence interval (CI) 0.20-0.41) to 0.48 (95% CI 0.40-0.57) (p<0.01). In all, nine cases were exposed to maternal mental health conditions/medications (adjusted odds ratio (adjOR) 2.64, 95% CI 1.33-5.21) compared with cardiac controls. Cases were more likely to be exposed to maternal β-thalassemia (adjOR 10.5, 95% CI 3.13-35.3, n=3) and haemorrhage in early pregnancy (adjOR 1.77, 95% CI 0.93-3.38, n=11) compared with cardiac controls.

CONCLUSIONS

The increasing prevalence of Ebstein's anomaly may be related to better and earlier diagnosis. Our data suggest that Ebstein's anomaly is associated with maternal mental health problems generally rather than lithium or benzodiazepines specifically; therefore, changing or stopping medications may not be preventative. We found new associations requiring confirmation.

Proportion of selected congenital heart defects attributable to recognized risk factors

PURPOSE

To assess the contribution of multiple risk factors for two congenital heart defects-hypoplastic left heart syndrome (HLHS) and tetralogy of Fallot (TOF).

METHODS

We used data from the National Birth Defects Prevention Study (1997-2011) to estimate average adjusted population attributable fractions for several recognized risk factors, including maternal prepregnancy overweight-obesity, pregestational diabetes, age, and infant sex.

RESULTS

There were 594 cases of isolated simple HLHS, 971 cases of isolated simple TOF, and 11,829 controls in the analysis. Overall, 57.0% of HLHS cases and 37.0% of TOF cases were estimated to be attributable to risk factors included in our model. Among modifiable HLHS risk factors, maternal prepregnancy overweight-obesity accounted for the largest proportion of cases (6.5%). Among modifiable TOF risk factors, maternal prepregnancy overweight-obesity and maternal age of 35 years or older accounted for the largest proportions of cases (8.3% and 4.3%, respectively).

CONCLUSIONS

Approximately half of HLHS cases and one-third of TOF cases were estimated to be attributable to risk factors included in our models. Interventions targeting factors that can be modified may help reduce the risk of HLHS and TOF development. Additional research into the etiology of HLHS and TOF may reveal other modifiable risk factors that might contribute to primary prevention efforts.

Maternal Chlamydia Infection During Pregnancy and Risk of Cyanotic Congenital Heart Defects in the Offspring

OBJECTIVES

Genital Chlamydia is a common bacterial sexually-transmitted infection among reproductive aged women, particularly younger populations. Cyanotic congenital heart defects (CCHDs) constitute about one quarter of all cardiac malformations at birth, and are associated with high rate of morbidity and mortality. Epidemiological research on the association between maternal Chlamydia during pregnancy and CCHDs in the offspring is lacking.

METHODS

Using data from the 2012 United States birth certificates, we examined the association between CCHDs and prenatal exposure to Chlamydia among live singleton births with CCHDs (n = 2487) and unaffected singleton births (n = 3,334,424). We estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) using unconditional logistic regression analysis for all CCHDs combined, and isolated CCHDs (without other major congenital malformations).

RESULTS

Overall 1.7% of case and 1.7% of control women reported having Chlamydia during their pregnancies. After controlling for potential confounders, we found a weak positive association between maternal Chlamydia during pregnancy and all CCHDs combined (aOR = 1.39; 95% CI 1.02-1.90). The positive association persisted for isolated CCHD cases, but with marginal significance (aOR = 1.34; 95% CI 0.96-1.74). Subgroup analyses for younger women showed an increased risk for CCHDs; however, the associations were not statistically significant.

CONCLUSIONS

Maternal exposure to Chlamydia during pregnancy was weakly associated with a higher risk of CCHDs in the offspring. The finding should be interpreted with caution due to limitations of birth certificate data. Future studies using more robust data sources are warranted to further study the association between maternal Chlamydia during pregnancy and CCHDs in the offspring.

Risk factors of different congenital heart defects in Guangdong, China

BACKGROUND

Limited studies have evaluated the risk factors for congenital heart defects (CHDs) in China and compared them for different types of CHDs. This study examined risk factors between isolated and multiple CHDs as well as among CHDs subtypes in Guangdong, Southern China.

METHODS

This population-based case-control study included 4,034 pairs of case and control infants enrolled in the Guangdong Registry of CHD study, 2004-2013. Multivariate logistic regression was used to compute adjusted odds ratios (ORs) while simultaneously controlling for confounders.

RESULTS

Multiple maternal environmental exposures, including living in newly renovated rooms, residential proximity to main traffic, paternal smoking, and maternal occupation as manual worker, were significantly associated with CHDs with ORs ranging 1.30-9.43. Maternal perinatal diseases (including maternal fever, diabetes, influenza, and threatened abortion), maternal medication use (antibiotic use), advanced maternal age, low socioeconomic status, and paternal alcohol intake were also significantly associated with CHDs, with ORs ranging 1.60-3.96. Isolated CHDs and multiple defects have different profiles of risk factors, while subtype of CHD shares common risk factors.

CONCLUSION

These results suggest that maternal environmental exposures/occupation and perinatal diseases/medication use were dominant risk factors associated with CHDs in Southern China. Isolated and multiple CHDs may have different etiologic factors.

Preventing birth defects: The value of the NBDPS case-control approach

Birth Defect Registries provide a basis for epidemiological research into risk factors, thus facilitating a growing understanding of what causes congenital anomalies and how one might target preventive public health actions and reduce inequalities. The National Birth Defects Prevention Study (NBDPS) has used 10 U.S. registries as a basis for a large case-control study. This commentary reviews its methodology and selected areas of output. The strengths of NBDPS lie in the quality of diagnostic coding and classification of birth defects and its size. The sources of bias in NBDPS data relate particularly to retrospective exposure ascertainment entailing a long period of recall, incomplete ascertainment of terminations of pregnancy for fetal anomaly, and unknown bias in case selection. NBDPS results have shown the protective effect of healthy dietary patterns, but have not been as informative as expected in relation to furthering understanding of the protective effect of folic acid. NBDPS medication studies are making important contributions to addressing the gap in existing evidence systematically across a wide range of birth defects, but are challenged by the quality of information on exposure, dose and underlying disease condition, and the interpretation of results of multiple testing. Studies of environmental contaminants in collaboration with experts in exposure assessment have linked addresses to residential exposure measures, using the advantages of information on residential history and confounders, but are challenged by the need to consider exposure mixtures. NBDPS could increase its public health impact by placing more emphasis on socioeconomic inequalities.

Paternal age and offspring congenital heart defects: a national cohort study

Paternal age has been associated with offspring congenital heart defects (CHDs), which might be caused by increased mutations in the germ cell line because of cumulated cell replications. Empirical evidences, however, remain inconclusive. Furthermore, it is unknown whether all subtypes of CHDs are affected by paternal age. We aimed to explore the relationship between paternal age and the risk of offspring CHDs and its five common subtypes using national register data in Denmark. A total of 1 893 899 singletons born in Denmark from 1977 to 2008 were included in this national-based cohort study. Cox’s proportion hazards model with robust sandwich estimate option was used to estimate the hazards ratio (95% confidence interval) for the associations between paternal age and all CHDs, as well as subtypes of CHDs (patent ductus arteriosus (PDA), ventricular septal defect (VSD), atrial septal defect (ASD), tetralogy of fallot (TOF) and coarctation of the aorta (CoA)). We did not observe an overall association between paternal age and offspring CHDs. However, compared to the paternal age of 25–29 years, paternal age of older than 45 years was associated with a 69% increased risk of PDA (HR45+ = 1.69, 95%CI:1.17–2.43). We observed similar results when subanalyses were restricted to children born to mothers of 27–30 years old. After taking into consideration of maternal age, our data suggested that advanced paternal age was associated with an increased prevalence of one subtype of offspring congenital heart defects (CHDs), namely patent ductus arteriosus (PDA).