Maternal thyroid disease, thyroid medication use, and selected birth defects in the National Birth Defects Prevention Study

Pre-Conceptional and Antenatal Care for Improved Newborn and Child Survival in India: A Review

There is sufficient scientific evidence that quality pre-conceptional care and antenatal care can improve newborn survival. This review was conducted to understand the concept of pre-conceptional care and its implementation status in India. The review documents the specific interventions that have been proven to effectively improve pregnancy outcome when provided as pre-conception care. Healthcare providers, particularly obstetricians/gynecologists and general physicians, should prioritize pre-conception care as an essential component of healthcare for women. However, the lack of continuum of care and program linkages are some of the key barriers in ensuring pre-conceptional and ante-natal care in India. Culturally and linguistically appropriate care should be provided to ensure that all women can access and understand the information and services needed to optimize their reproductive health and improve pregnancy outcomes. Prioritizing pre-conception and prenatal care, healthcare providers can improve maternal and fetal outcomes, reduce healthcare costs, and promote lifelong health for women and their families. The primary healthcare reforms being done in India can be and should be used to strengthen pre-conceptional and ante-natal care services and quality.

Oxidative balance scores and neural crest cell-related congenital anomalies

Oxidative stress and redox imbalance adversely affect embryonic development. We developed two oxidative balance scores (OBS) that include dietary and nondietary exposures. We hypothesized that higher scores (i.e., lower oxidative stress) would be associated with lower risk of neural tube defects, orofacial clefts, conotruncal heart defects, and limb deficiencies. We used data from the National Birth Defects Prevention Study to create a dietary OBS based on intake of 13 nutrients and an overall OBS that included the 13 nutrients and eight additional nondietary factors related to oxidative balance (e.g., smoking). We used logistic regression to examine odds ratios associated with having low or high scores (i.e., <10th or >90th percentiles). Continuous models indicated reduced odds associated with high versus low scores (i.e., comparing odds at the 90th versus 10th percentile values of the distribution) on the overall OBS for cleft lip with or without cleft palate [adjusted odds ratio (aOR) 0.72, 95% confidence interval (CI) 0.63-0.82], longitudinal limb deficiency (aOR 0.73, CI 0.54-0.99), and transverse limb deficiency (aOR 0.74, CI 0.58-0.95); increased odds for anencephaly (aOR 1.40, CI 1.07-1.84); and primarily nonsignificant associations with conotruncal heart defects. Results for the dietary OBS were similar. This study provides some evidence that oxidative stress contributes to congenital anomalies related to neural crest cell development.

A Novel Inflammatory Marker for the Diagnosis of Hashimoto's Thyroiditis: Platelet-Count-to-Lymphocyte-Count Ratio

BACKGROUND

Hashimoto's thyroiditis (HT) is a chronic autoimmune thyroiditis that causes systemic inflammation in the body, leading to hypothyroidism and an enlargement of the thyroid gland.

OBJECTIVES

This study aims to reveal whether there is a relationship between Hashimoto's thyroiditis and the platelet-count-to-lymphocyte-count ratio (PLR), which is used as a new inflammatory marker.

METHODS

In this retrospective study, we compared the PLR of the euthyroid HT group and the hypothyroid-thyrotoxic HT group to the controls. We also evaluated the values of thyroid-stimulating hormone (TSH), free T4 (fT4), C-reactive protein (CRP), aspartate transaminase (AST), alanine transaminase (ALT), white blood cell count, lymphocyte count, hemoglobin, hematocrit, and platelet count in each group.

RESULTS

The PLR of the subjects with Hashimoto's thyroiditis was found to be significantly different from the control group (p < 0.001), with the rankings as follows: hypothyroid-thyrotoxic HT 177% (72-417) > euthyroid HT 137% (69-272) > control group 103% (44-243). In addition to the increased PLR values, an increase in CRP values was also observed, revealing a strong positive correlation between the PLR and CRP in the HT patients.

CONCLUSION

In this study, we found out that the PLR was higher in the hypothyroid-thyrotoxic HT and euthyroid HT patients than in a healthy control group.

Spatial analysis of hypospadias cases in northern France: taking clinical data into account

Background

Strong evidence for a causal role of environmental factors in a congenital anomaly is still difficult to produce. The collection of statistical data is crucial for gaining a better understanding of the epidemiology and pathophysiology of these anomalies. We aimed to evaluate spatial variations in hypospadias within our region and it’s association to socioeconomic and ecological factors, taking clinical data into account.

Methods

All boys with hypospadias born in northern France and seen in Lille University Medical Center (Lille, France) between 1999 and 2012 were included in the analysis. We retrospectively collected geographic data, clinical data (especially known confounding factors associated with an elevated risk of hypospadias), and demographic, socio-economic and ecological data. We analyzed the entire study population and subsequently the subset of boys lacking confounding factors.

Results

The study sample of 975 cases of hypospadias over the 13-year period resulted in an incidence of 25.4/10,000 male births, and was characterized by significant spatial heterogeneity (p < 0.005) and autocorrelation (p < 0.001). We detected two high-incidence clusters that differed with regard to their land use. After the exclusion of 221 patients with confounding factors, two high-incidence clusters with significant disease risks (1.65 and 1.75, respectively; p < 0.001) and a significant difference in land use (p < 0.001) again appeared. The first cluster contained a higher median [interquartile range] proportion of artificialized land (0.40 [0.22;0.47]) than the remaining “neutral areas” (0.19 [0.08;0.53]) did (p < 0.001). Conversely, the second cluster contained a higher median proportion of rural land (0.90 [0.78;0.96]) than the “neutral areas” (0.81 [0.47;0.92]) did (p < 0.001). The median deprivation index was significantly lower in the urban cluster (0.47 [0.42;0.55]) and significantly higher in the rural cluster (0.69 [0.56;0.73]) (p < 0.001).

Conclusions

Our results evidenced the heterogeneous spatial distribution of cases of hypospadias in northern France. We identified two clusters with different environmental and social patterns – even after the exclusion of known confounding factors.

Occupational exposure to endocrine-disrupting chemicals and other parental risk factors in hypospadias and cryptorchidism development: a case-control study

AIM OF THE STUDY

Endocrine-disrupting chemicals (EDCs) are exogenous agents that are capable of altering the endocrine system functions, including the regulation of developmental processes. The aim of this study was to investigate the association between EDC exposure and other parental factors in the etiology of hypospadias and cryptorchidism.

METHODS

A case-control study was conducted. Cases (n = 210) were infants aged between 6 months and 14 years diagnosed with hypospadias or cryptorchidism who attended the authors' hospital over a period of 18 months, and controls (n = 210) were infants within the same range of age and without any urological disorders who attended the outpatient clinic of the same hospital during the same time period. Their selection was independent of exposures. Data on parental occupational exposure to EDCs and other sociodemographic variables were collected through face-to-face interviews and systematically for both cases and controls. Crude and adjusted odds ratios (ORs) were estimated to control for confounding with their 95% confidence interval (CI) by means of logistic regressions. Specifically, three final models of a dichotomous outcome were constructed: one for cryptorchidism, one for hypospadias, and the third considering both malformations together. The Hosmer-Lemeshow test was used to assess the goodness of fit of the models. Their discriminatory accuracy (DA) was ascertained by estimating their areas under the receiver operating characteristic curves area under the curve (AUC) along with their 95% CI.

RESULTS

Associations were found between advanced maternal age (OR adjusted = 1.82; 95% CI: 1.14-2.92), mother's consumption of anti-abortives (OR = 5.40; 95% CI: 1.40-38.5) and other drugs (OR = 2.02; 95% CI: 1.31-3.16) during pregnancy, maternal and paternal occupational exposure to EDCs (OR = 4.08; 95% CI: 2.03-8.96 and OR = 3.90; 95% CI: 2.41-6.48, respectively), fathers smoking (OR = 2.0; 95% CI: 1.33-2.99), and fathers with urological disorders (OR = 2.31; 95% CI: 1.15-4.90). Maternal and paternal high educational level could be protective of cryptorchidism (OR = 0.47; 95% CI: 0.28-0.76 and OR = 0.63; 95% CI: 0.42-0.93, respectively). The DA of the models for the whole sample (AUC = 0.75; 95% CI: 0.70-0.79) for cryptorchidism (AUC = 0.76; 95% CI: 0.71-0.82) and for hypospadias (AUC = 0.75; 95% CI: 0.69-0.81) was moderately high.

CONCLUSIONS

Advanced age, some parental occupational exposure to EDCs, some drug consumption, smoking, and the father's history of urological disorders may increase risk and predict the developments of these malformations. Studies with higher samples sizes are needed to assess associations between individual EDC occupational exposures and drugs and these malformations.

An application of data mining to identify potential risk factors for anophthalmia and microphthalmia

BACKGROUND

We examined a large number of variables to generate new hypotheses regarding a wider range of risk factors for anophthalmia/microphthalmia using data mining.

METHODS

Data were from the National Birth Defects Prevention Study, a multicentre, case-control study from 10 centres in the United States. There were 134 cases of "isolated" and 87 "nonisolated" (with other major birth defects) of anophthalmia/microphthalmia and 11 052 nonmalformed controls with delivery dates October 1997-December 2011. Using random forest, a data mining procedure, we compared the two case types with controls for 201 variables. Variables considered important ranked by random forest were included in a multivariable logistic regression model to estimate odds ratios and 95% confidence intervals.

RESULTS

Predictors for isolated cases included paternal race/ethnicity, maternal intake of certain nutrients and foods, and childhood health problems in relatives. Using regression, inverse associations were observed with greater maternal education and with increasing intake of folate and potatoes. Odds were slightly higher with greater paternal education, for increased intake of carbohydrates and beans, and if relatives had a childhood health problem. For nonisolated cases, predictors included paternal race/ethnicity, maternal intake of certain nutrients, and smoking in the home the month before conception. Odds were higher for Hispanic fathers and smoking in the home and NSAID use the month before conception.

CONCLUSIONS

Results appear to support previously hypothesised risk factors, socio-economic status, NSAID use, and inadequate folate intake, and potentially provide new areas such as passive smoking pre-pregnancy, and paternal education and ethnicity, to explore for further understanding of anophthalmia/microphthalmia.

Nongenetic risk factors for holoprosencephaly: An updated review of the epidemiologic literature

Holoprosencephaly (HPE) is a major structural birth defect of the brain that occurs in approximately 1 in 10,000 live births. Although some genetic causes of HPE are known, a substantial proportion of cases have an unknown etiology. Due to the low birth prevalence and rarity of exposure to many potential risk factors for HPE, few epidemiologic studies have had sufficient sample size to examine risk factors. A 2010 review of the literature identified several risk factors that had been consistently identified as occurring more frequently among cases of HPE, including maternal diabetes, twinning, and a predominance of females, while also identifying a number of potential risk factors that had been less widely studied. In this article, we summarize a systematic literature review conducted to update the evidence for nongenetic risk factors for HPE.

Maternal drug use and the risk of anorectal malformations: systematic review and meta-analysis

Background

Origin of anorectal malformations (ARM) are considered multifactorial. Several genetic and non-genetic risk factors are discussed in literature. Maternal periconceptional medical drug use as possible risk factor, however, has not been reviewed systematically.

Methods

Studies published between 1977 and April 2017 were reviewed through systematic search in PubMed, ISI Web of Knowledge and Scopus databases. Furthermore, related and cross-referencing publications were reviewed. Pooled odds ratios (95% confidence intervals) were determined to quantify associations of maternal periconceptional use of folic acid, multivitamins, anti-asthma medication (separated in any anti-asthma medication, inhaled corticosteroids and salbutamol), thyroid hormone supplements, psychiatric drugs (separated in antidepressants, any selective serotonin reuptake inhibitors [SSRI], sertraline, citalopram, fluoxetine, paroxetine, hypnotics and benzodiazepine) and aspirin with ARM using meta-analyses.

Results

Thirty-seven studies that reported on the association between maternal periconceptional drug intake and infants born with ARM were included in this review. These were conducted in the United States of America (n = 14), Sweden (n = 6), Hungary (n = 5), Germany (n = 3), the Netherlands (n = 3), Denmark (n = 2), France (n = 2), Norway (n = 1) and the UK (n = 1). However, only few of these studies reported on the same risk factors. Studies were heterogeneous with respect to case numbers, period ingestion of medical drug use, control selection and adjustment for covariates. Consistently increased risks were observed for any anti-asthma medication, and hypnotics and benzodiazepine, but not for folic acid, multivitamins, inhaled corticosteroids, salbutamol, thyroid hormone supplements, antidepressants, any SSRI, sertraline, citalopram, fluoxetine, paroxetine and aspirin. In meta-analyses, pooled odds ratios (95% confidence intervals) for any anti-asthma medication, and hypnotics and benzodiazepine were 1.64 (1.22–2.21), and 2.43 (1.03–5.73), respectively.

Conclusion

Evidence on maternal drug use before conception and during pregnancy as risk factor for ARM from epidemiological studies is still very limited. Nevertheless, the few available studies indicate any anti-asthma medication, and hypnotics and benzodiazepine to be associated with increased risks. Further, ideally large-scale multicenter and register-based studies are needed to clarify the role of maternal drug intake for the development of ARM.

Maternal environment and craniofacial growth: geometric morphometric analysis of mandibular shape changes with in utero thyroxine overexposure in mice

An estimated 3% of US pregnancies are affected by maternal thyroid dysfunction, with between one and three of every 1000 pregnancies being complicated by overactive maternal thyroid levels. Excess thyroid hormones are linked to neurological impairment and excessive craniofacial variation, affecting both endochondral and intramembranous bone. Using a geometric morphometric approach, this study evaluates the role of in utero thyroxine overexposure on the growth of offspring mandibles in a sample of 241 mice. Canonical variate analysis utilized 16 unilateral mandibular landmarks obtained from 3D micro-computed tomography to assess shape changes between unexposed controls (n = 63) and exposed mice (n = 178). By evaluating shape changes in the mandible among three age groups (15, 20 and 25 days postnatal) and different dosage levels (low, medium and high), this study found that excess maternal thyroxine alters offspring mandibular shape in both age- and dosage-dependent manners. Group differences in overall shape were significant (P < 0.001), and showed major changes in regions of the mandible associated with muscle attachment (coronoid process, gonial angle) and regions of growth largely governed by articulation with the cranial base (condyle) and occlusion (alveolus). These results compliment recent studies demonstrating that maternal thyroxine levels can alter the cranial base and cranial vault of offspring, contributing to a better understanding of both normal and abnormal mandibular development, as well as the medical implications of craniofacial growth and development.

Thyroid Medication Use and Birth Defects in the National Birth Defects Prevention Study

BACKGROUND

Thyroid disorders are common among reproductive-aged women, with hypothyroidism affecting 2 to 3% of pregnancies, and hyperthyroidism affecting an additional 0.1 to 1%. We examined associations between thyroid medications and individual birth defects using data from the National Birth Defects Prevention Study (NBDPS).

METHODS

The NBDPS is a multisite, population-based, case-control study that included pregnancies with estimated delivery dates from 1997 to 2011. We analyzed self-reported thyroid medication use from mothers of 31,409 birth defect cases and 11,536 unaffected controls. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression for birth defects with five or more exposed cases, controlling for maternal age, race/ethnicity, and study center. Crude ORs and exact 95% CIs were estimated for defects with 3 to 4 exposed cases.

RESULTS

Thyroid hormone was used by 738 (2.3%) case and 237 (2.1%) control mothers, and was associated with anencephaly (OR = 1.68; 95% CI, 1.03-2.73), holoprosencephaly (OR = 2.48; 95% CI, 1.13-5.44), hydrocephaly (1.77; 95% CI, 1.07-2.95) and small intestinal atresia (OR = 1.81; 95% CI, 1.04-3.15). Anti-thyroid medication was used by 34 (0.1%) case and 10 (<0.1%) control mothers, and was associated with aortic valve stenosis (OR = 6.91; 95% CI, 1.21-27.0).

CONCLUSION

While new associations were identified, our findings are relatively consistent with previous NBDPS analyses. Our findings suggest thyroid medication use is not associated with most birth defects studied in the NBDPS, but may be associated with some specific birth defects. These results should not be interpreted to suggest that medications used to treat thyroid disease are teratogens, as the observed associations may reflect effects of the underlying thyroid disease. Birth Defects Research 109:1471-1481, 2017.© 2017 Wiley Periodicals, Inc.

Primary Prevention of Congenital Anomalies: Special Focus on Environmental Chemicals and other Toxicants, Maternal Health and Health Services and Infectious Diseases

Congenital anomalies (CA) represent an important fraction of rare diseases, due to the critical role of non-genetic factors in their pathogenesis. CA are the main group of rare diseases in which primary prevention measures will have a beneficial impact. Indeed, since 2013 the European Union has endorsed a body of evidence-based recommendations for CA primary prevention; the recommendations aim at facilitating the inclusion of primary prevention actions the National Rare Disease Plans of EU Member States and encompass different public health fields, from environment through to maternal diseases and lifestyles.The chapter overviews and discusses the assessment of main risk factors for CA, such as environmental toxicants, maternal health and lifestyles and infections, with a special attention to issues that are emerging or need more knowledge.Overall, the availability of CA registries is important for estimating the health burden of CA, identifying possible hotspots, assessing the impact of interventions and addressing further, fit-to-purpose research.The integration of relevant public health actions that are already in place (e.g., control of noxious chemicals, vaccination programmes, public health services addressing chronic maternal conditions) can increase the affordability and sustainability of CA primary prevention. In developing countries with less primary prevention in place and limited overall resources, a first recognition phase may be pivotal in order to identify priority targets. In the meanwhile, policy makers should be made aware that primary prevention of RD supports publicly endorsed societal values like the knowledge-based promotion of health, empowerment, equity and social inclusiveness.

Prevalence of prescription medication use among non-pregnant women of childbearing age and pregnant women in the United States: NHANES, 1999-2006

Many prescription medications have limited information regarding safety for use during pregnancy. In order to inform research on safer medication use during pregnancy, we examined prescription medication use among women in the United States. We analyzed data from the 1999-2006 National Health and Nutrition Examination Survey (NHANES) to estimate the prevalence of prescription medication use in the past 30 days among pregnant women and non-pregnant women of childbearing age (15-44 years) and to ascertain the most commonly reported prescription medications by women in these groups. We assessed how the most commonly reported medications differed among groups defined by selected demographic characteristics, including age, race/ethnicity, and markers of socioeconomic status. Prescription medication use in the past 30 days was reported by 22 % of pregnant women and 47 % of non-pregnant women of childbearing age. The most commonly reported prescription medications by NHANES participants differed somewhat by pregnancy status; allergy and anti-infective medications were more common among pregnant women, while oral contraceptives were more common among non-pregnant women. Use of prescription medication for asthma and thyroid disorders was reported by both groups. Although prescription medication use in the previous 30 days was less common among pregnant women than non-pregnant women, its use was reported among almost 1 in 4 pregnant women. Many of the most common medications reported were for the treatment of chronic medical conditions. Given the potential impact of medications on the developing fetus, our data underscore the importance of understanding the safety of these medications during pregnancy.

Residential agricultural pesticide exposures and risks of selected birth defects among offspring in the San Joaquin Valley of California

BACKGROUND

We examined associations of birth defects with residential proximity to commercial agricultural pesticide applications in California. Subjects included 367 cases representing five types of birth defects and 785 nonmalformed controls born 1997 to 2006.

METHODS

Associations with any versus no exposure to physicochemical groups of pesticides and specific chemicals were assessed using logistic regression adjusted for covariates. Overall, 46% of cases and 38% of controls were classified as exposed to pesticides within a 500 m radius of mother's address during a 3-month periconceptional window.

RESULTS

We estimated odds ratios (ORs) for 85 groups and 95 chemicals with five or more exposed cases and control mothers. Ninety-five percent confidence intervals (CI) excluded 1.0 for 11 ORs for groups and 22 ORs for chemicals, ranging from 1.9 to 3.1 for groups and 1.8 to 4.9 for chemicals except for two that were <1 (noted below).

CONCLUSION

For groups, these ORs were for anotia/microtia (n = 95 cases) and dichlorophenoxy acids/esters and neonicotinoids; anorectal atresia/stenosis (n = 77) and alcohol/ethers and organophosphates (these ORs were < 1.0); transverse limb deficiencies (n = 59) and dichlorophenoxy acids/esters, petroleum derivatives, and triazines; and craniosynostosis (n = 79) and alcohol/ethers, avermectins, neonicotinoids, and organophosphates. For chemicals, ORs were: anotia/microtia and five pesticides from the groups dichlorophenoxy acids/esters, copper-containing compounds, neonicotinoids, organophosphates, and triazines; transverse limb deficiency and six pesticides - oxyfluorfen and pesticides from the groups copper-containing compounds, 2,6-dinitroanilines, neonicotinoids, petroleum derivatives and polyalkyloxy compounds; craniosynostosis and 10 pesticides - oxyfluorfen and pesticides from the groups alcohol/ethers, avermectins, n-methyl-carbamates, neonicotinoids, ogranophosphates (two chemicals), polyalkyloxy compounds (two chemicals), and pyrethroids; and congenital diaphragmatic hernia (n = 62) and a copper-containing compound.

Maternal hypothyroidism may be associated with CHD in offspring

OBJECTIVES

This study tested whether mothers with maternal hypothyroidism have increased odds of CHD in their offspring, and examined the relationship between CHD, maternal thyroid function, and nausea and vomiting in pregnancy.

BACKGROUND

Maternal hypothyroidism increases the risk for foetal demise and prematurity and can have a negative impact on neurodevelopment. Prior studies have postulated a relationship between maternal thyroid function, CHD, and maternal nausea and vomiting in pregnancy.

METHODS

A cross-sectional case-control study was conducted over a 17-month period to obtain a history of maternal thyroid status and nausea and vomiting in pregnancy. Paediatric echocardiograms were evaluated for CHD by a blinded paediatric cardiologist. Logistic regression analysis was performed to examine the association between CHD and maternal hypothyroidism.

RESULTS

Of the 998 maternal-child pairs, 10% (98/998) of the mothers reported a history of prenatal hypothyroidism. The overall prevalence of CHD in the study sample was 63% (630/998). Mothers with a history of hypothyroidism were significantly more likely to have offspring with CHD compared with mothers without a history of hypothyroidism (72 versus 62%; p=0.04). The adjusted odds ratio (95% confidence interval) of CHD in offspring associated with reported maternal hypothyroidism was 1.68 (1.02-2.78).

CONCLUSION

This study suggests that maternal hypothyroidism is a risk factor for the development of CHD. Further prospective investigations are necessary to confirm this association and delineate pathogenic mechanisms.

Maternal factors in the origin of isolated anorectal malformations - a population-based case-control study

OBJECTIVE

In most patients affected by isolated anorectal malformation (IARM), the etiology is unknown. Thus, the aim of this study was to analyze the possible role of maternal risk factors in the origin of IARM.

METHODS

The study samples included 231 cases with IARM, 361 matched and 38 151 population controls without any defect in the population-based large dataset of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996. Cases with IARM were evaluated in the function of maternal diseases and related drug use.

RESULTS

The findings of this case-control study suggested that cases with IARM have an obvious male excess. The mothers of cases with IARM had a lower incidence of severe nausea and vomiting in pregnancy and a higher incidence of acute infectious diseases in the urinary tract.

CONCLUSIONS

Lack of nausea and vomiting in pregnancy and the higher incidence of urinary tract infections may have a role in the development of IARM.

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.

Primary prevention of congenital anomalies: recommendable, feasible and achievable

Primary prevention of congenital anomalies was identified as an important action in the field of rare diseases by the European Commission in 2008, but it was not included in the Council Recommendation on an action in the field of rare diseases in 2009. However, primary prevention of congenital anomalies is feasible because scientific evidence points to several risk factors (e.g., obesity, infectious and toxic agents) and protective factors (e.g., folic acid supplementation and glycemic control in diabetic women). Evidence-based community actions targeting fertile women can be envisaged, such as risk-benefit evaluation protocols on therapies for chronic diseases, vaccination policies, regulations on workplace and environmental exposures as well as the empowerment of women in their lifestyle choices. A primary prevention plan can identify priority targets, exploit and integrate ongoing actions and optimize the use of resources, thus reducing the health burden for the new generation. The EUROCAT-EUROPLAN recommendations for the primary prevention of congenital anomalies endorsed in 2013 by the European Union Committee of Experts on Rare Diseases present an array of feasible and evidence-based measures from which national plans can adopt and implement actions based on country priorities. Primary prevention of congenital anomalies can be achieved here and now and should be an integral part of national plans on rare diseases.

Geographic analysis of individual and environmental risk factors for hypospadias births

BACKGROUND

Hypospadias is a relatively common birth defect affecting the male urinary tract. We explored the etiology of hypospadias by examining its spatial distribution in North Carolina and the spatial clustering of residuals from individual and environmental risk factors.

METHODS

We used data collected by the North Carolina Birth Defects Monitoring Program from 2003 to 2005 to estimate local Moran's I statistics to identify geographic clustering of overall and severe hypospadias, using 995 overall cases and 16,013 controls. We conducted logistic regression and local Moran's I statistics on standardized residuals to consider the contribution of individual variables (maternal age, maternal race/ethnicity, maternal education, smoking, parity, and diabetes) and environmental variables (block group land cover) to this clustering.

RESULTS

Local Moran's I statistics indicated significant clustering of overall and severe hypospadias in eastern central North Carolina. Spatial clustering of hypospadias persisted when controlling for individual factors, but diminished somewhat when controlling for environmental factors. In adjusted models, maternal residence in a block group with more than 5% crop cover was associated with overall hypospadias (odds ratio = 1.22; 95% confidence interval = 1.04-1.43); that is living in a block group with greater than 5% crop cover was associated with a 22% increase in the odds of having a baby with hypospadias. Land cover was not associated with severe hypospadias.

CONCLUSION

This study illustrates the potential contribution of mapping in generating hypotheses about disease etiology. Results suggest that environmental factors including proximity to agriculture may play some role in the spatial distribution of hypospadias. Birth Defects Research (Part A) 100:887-894, 2014. © 2014 Wiley Periodicals, Inc.

Preconception care: screening and management of chronic disease and promoting psychological health

INTRODUCTION

A large proportion of women around the world suffer from chronic diseases including mental health diseases. In the United States alone, over 12% of women of reproductive age suffer from a chronic medical condition, especially diabetes and hypertension. Chronic diseases significantly increase the odds for poor maternal and newborn outcomes in pregnant women.

METHODS

A systematic review and meta-analysis of the evidence was conducted to ascertain the possible impact of preconception care for preventing and managing chronic diseases and promoting psychological health on maternal, newborn and child health outcomes. A comprehensive strategy was used to search electronic reference libraries, and both observational and clinical controlled trials were included. Cross-referencing and a separate search strategy for each preconception risk and intervention ensured wider study capture.

RESULTS

Maternal prepregnancy diabetic care is a significant intervention that reduces the occurrence of congenital malformations by 70% (95% Confidence Interval (CI): 59-78%) and perinatal mortality by 69% (95% CI: 47-81%). Furthermore, preconception management of epilepsy and phenylketonuria are essential and can optimize maternal, fetal and neonatal outcomes if given before conception. Ideally changes in antiepileptic drug therapy should be made at least 6 months before planned conception. Interventions specifically targeting women of reproductive age suffering from a psychiatric condition show that group-counseling and interventions leading to empowerment of women have reported non-significant reduction in depression (economic skill building: Mean Difference (MD) -7.53; 95% CI: -17.24, 2.18; counseling: MD-2.92; 95% CI: -13.17, 7.33).

CONCLUSION

While prevention and management of the chronic diseases like diabetes and hypertension, through counseling, and other dietary and pharmacological intervention, is important, delivering solutions to prevent and respond to women's psychological health problems are urgently needed to combat this leading cause of morbidity.

Differences in risk factors for second and third degree hypospadias in the national birth defects prevention study

BACKGROUND

Hypospadias is a frequent birth defect with three phenotypic subtypes. With data from the National Birth Defects Prevention Study, a large, multi-state, population-based, case-control study, we compared risk factors for second and third degree hypospadias.

METHODS

A wide variety of data on maternal and pregnancy-related risk factors for isolated second and third degree hypospadias was collected by means of computer-assisted telephone interviews to identify potential etiological differences between the two phenotypes. Logistic regression was used to calculate odds ratios including a random effect by study center.

RESULTS

In total, 1547 second degree cases, 389 third degree cases, and 5183 male controls were included in our study. Third degree cases were more likely to have a non-Hispanic black or Asian/Pacific Islander mother, be delivered preterm, have a low birth weight, be small for gestational age, and be conceived with fertility treatments than second degree cases and controls. Associations with both second and third degree hypospadias were observed for maternal age, family history, parity, plurality, and hypertension during pregnancy. Risk estimates were generally higher for third degree hypospadias except for family history.

CONCLUSION

Most risk factors were associated with both or neither phenotype. Therefore, it is likely that the underlying mechanism is at least partly similar for both phenotypes. However, some associations were different between second and third degree hypospadias, and went in opposite directions for second and third degree hypospadias for Asian/Pacific Islander mothers. Effect estimates for subtypes of hypospadias may be over- or underestimated in studies without stratification by phenotype.

Evaluation of developmental toxicity of propylthiouracil and methimazole

BACKGROUND

Propylthiouracil (PTU) and methimazole (MMI) are antithyroid drugs used to treat hyperthyroidism. Despite the widespread use of PTU and MMI during pregnancy, modest clinical data and less animal data are available on the teratogenic potential of these drugs.

METHODS

We evaluated the teratogenicity of in utero exposure to PTU or MMI in mice and rats. First, pregnant C57Bl/6 mice were treated daily with PTU (10 or 100 mg/kg), MMI (2 or 20 mg/kg), or vehicle from gestation day (GD) 6 to 16. GD 18 fetuses were evaluated for gross and histopathological abnormalities. Next, pregnant Sprague-Dawley rats were treated daily with PTU (50 or 100 mg/kg), MMI (10 or 20 mg/kg), or vehicle from GD 6 to 19, followed by evaluation for gross and histopathological abnormalities at GD 20.

RESULTS

In mice treated with PTU or MMI, no significant histopathological abnormalities or external gross malformations, and no adverse effects on placental weight, litter size, resorption rates, or fetal weight were observed at GD 18. In rats, no adverse effects on litter size, placental weights, or maternal body weights were observed with either PTU or MMI treatment. PTU treatment (50 and 100 mg/kg) and MMI (10 mg/kg) treatment resulted in a decrease in crown-rump length in rat fetuses but no external gross malformations or histopathological abnormalities were observed.

CONCLUSION

We did not observe either gross external malformations or histopathological malformations in mice or rats treated long-term with high doses of PTU or MMI during pregnancy.

Review of genetic and environmental factors leading to hypospadias

Hypospadias is one of the most common congenital malformations, affecting about 4-6 males per 1000 male births, and ranging in severity from a urethral meatus that is slightly off-center to a meatus in the perineal area. Over the past three decades its prevalence may have increased due to changes in reporting of mild cases and/or increased survival of low birth weight infants due to improved neonatal care. However, despite the increasing numbers of males with hypospadias, the overall etiology remains unclear and likely multifactorial in nature. The purpose of this review article is to provide a comprehensive overview of the various factors implicated in hypospadias etiology, including genetic and environmental factors. In addition, we list syndromes in which hypospadias is a relatively common association and delineate the areas that require further investigation in an effort to understand this condition.

Anorectal malformations and pregnancy-related disorders: a registry-based case-control study in 17 European regions

OBJECTIVE

To identify pregnancy-related risk factors for different manifestations of congenital anorectal malformations (ARMs).

DESIGN

A population-based case-control study.

SETTING

Seventeen EUROCAT (European Surveillance of Congenital Anomalies) registries, 1980-2008.

POPULATION

The study population consisted of 1417 cases with ARM, including 648 cases of isolated ARM, 601 cases of ARM with additional congenital anomalies, and 168 cases of ARM-VACTERL (vertebral, anal, cardiac, tracheo-esophageal, renal, and limb defects), along with 13 371 controls with recognised syndromes or chromosomal abnormalities.

METHODS

Multiple logistic regression analyses were used to calculate adjusted odds ratios (ORs) for potential risk factors for ARM, such as fertility treatment, multiple pregnancy, primiparity, maternal illnesses during pregnancy, and pregnancy-related complications.

MAIN OUTCOME MEASURES

Adjusted ORs for pregnancy-related risk factors for ARM.

RESULTS

The ARM cases were more likely to be firstborn than the controls (OR 1.6, 95% CI 1.4-1.8). Fertility treatment and being one of twins or triplets seemed to increase the risk of ARM in cases with additional congenital anomalies or VACTERL (ORs ranging from 1.6 to 2.5). Maternal fever during pregnancy and pre-eclampsia were only associated with ARM when additional congenital anomalies were present (OR 3.9, 95% CI 1.3-11.6; OR 3.4, 95% CI 1.6-7.1, respectively), whereas maternal epilepsy during pregnancy resulted in a five-fold elevated risk of all manifestations of ARM (OR 5.1, 95% CI 1.7-15.6).

CONCLUSIONS

This large European study identified maternal epilepsy, fertility treatment, multiple pregnancy, primiparity, pre-eclampsia, and maternal fever during pregnancy as potential risk factors primarily for complex manifestations of ARM with additional congenital anomalies and VACTERL.

Analysis of selected maternal exposures and non-syndromic atrioventricular septal defects in the National Birth Defects Prevention Study, 1997-2005

Although the descriptive epidemiology of atrioventricular septal defects (AVSDs), a group of serious congenital heart defects (CHDs), has been recently reported, non-genetic risk factors have not been consistently identified. Using data (1997-2005) from the National Birth Defects Prevention Study, an ongoing multisite population-based case-control study, the association between selected non-genetic factors and non-syndromic AVSDs was examined. Data on periconceptional exposures to such factors were collected by telephone interview from 187 mothers of AVSD case infants and 6,703 mothers of unaffected infants. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated from logistic regression models. Mothers who reported cigarette smoking during the periconceptional period were more likely to have infants with AVSDs compared with non-smokers, independent of maternal age, periconceptional alcohol consumption, infant gestational age, family history of CHDs, and study site (aOR 1.5, 95% CI 1.1-2.4). The association was strongest in mothers who smoked more than 25 cigarettes/day. In addition, mothers with periconceptional passive smoke exposure were more likely to have infants with AVSDs than unexposed mothers, independent of maternal age, active periconceptional smoking, infant gestational age, and family history of CHDs (aOR 1.4, 95% CI 1.0-2.0). No associations were observed between AVSDs and maternal history of a urinary tract infection or pelvic inflammatory disease, maternal use of a wide variety of medications, maternal occupational exposure, parental drug use, or maternal alcohol consumption. If the results of this preliminary study can be replicated, minimizing maternal active and passive smoke exposure may decrease the incidence of AVSDs.

Aetiology of hypospadias: a systematic review of genes and environment

BACKGROUND

Hypospadias is a common congenital malformation of the male external genitalia. Most cases have an unknown aetiology, which is probably a mix of monogenic and multifactorial forms, implicating both genes and environmental factors. This review summarizes current knowledge about the aetiology of hypospadias.

METHODS

Pubmed was used to identify studies on hypospadias aetiology published between January 1995 and February 2011. Reference lists of the selected manuscripts were also searched to identify additional studies, including those published before 1995.

RESULTS

The search provided 922 articles and 169 articles were selected for this review. Studies screening groups of patients with hypospadias for single gene defects found mutations in WT1, SF1, BMP4, BMP7, HOXA4, HOXB6, FGF8, FGFR2, AR, HSD3B2, SRD5A2, ATF3, MAMLD1, MID1 and BNC2. However, most investigators are convinced that single mutations do not cause the majority of isolated hypospadias cases. Indeed, associations were found with polymorphisms in FGF8, FGFR2, AR, HSD17B3, SRD5A2, ESR1, ESR2, ATF3, MAMLD1, DGKK, MID1, CYP1A1, GSTM1 and GSTT1. In addition, gene expression studies indentified CTGF, CYR61 and EGF as candidate genes. Environmental factors consistently implicated in hypospadias are low birthweight, maternal hypertension and pre-eclampsia, suggesting that placental insufficiency may play an important role in hypospadias aetiology. Exogenous endocrine-disrupting chemicals have the potential to induce hypospadias but it is unclear whether human exposure is high enough to exert this effect. Other environmental factors have also been associated with hypospadias but, for most, the results are inconsistent.

CONCLUSIONS

Although a number of contributors to the aetiology of hypospadias have been identified, the majority of risk factors remain unknown.

Thyroid function and pregnancy: before, during and beyond

Thyroid disturbances are common in women during the reproductive years of their lives. Autoimmunity and altered iodine status together account for a high proportion of the abnormalities. Autoimmune thyroid disease is present in around 4% of young females, and up to 15% are at risk because they are thyroid antibody-positive. There is a strong relationship between thyroid immunity on the one hand and infertility, miscarriage, and thyroid disturbances in pregnancy and postpartum on the other hand. Suboptimal iodine status affects a large proportion of the world's population, and pregnancy further depletes iodine stores. There is controversy surrounding the degree to which iodine should be supplemented and the duration of supplementation. Recent studies have helped to clarify the relationship between maternal thyroid status and neuropsychological development of the child. The role of other environmental factors including smoking and selenium status is also now recognised. Universal screening for thyroid hormone abnormalities is not routinely recommended at present. However, measurement of thyroid function and autoantibodies should certainly be considered in those who are at high risk of thyroid disease and in those whose pregnancy is otherwise high risk. The practicing clinician needs to be aware of the thyroid changes which accompany pregnancy.

Care of the pregnant thyroid cancer patient

PURPOSE OF REVIEW

Thyroid cancer is the fastest rising type of cancer among women in North America. Care of the pregnant patient with thyroid cancer is, therefore, of concern to obstetricians, internists and endocrine specialists. Guidelines for the care of the pregnant patient with thyroid disease were released by the Endocrine Society in late 2007, and a symposium on thyroid dysfunction and pregnancy was hosted by the American Thyroid Association in April 2009. With this increasing interest in thyroid disease and pregnancy, a variety of important studies have been published recently.

RECENT FINDINGS

In addition to guidelines published by the Endocrine Society, recent research has focused on detection and management of hypothyroidism in pregnancy, and consequences of hypothyroidism for the fetus and child. Impact of radioactive iodine therapy on subsequent fertility has been described. The risk of adverse outcomes due to thyroid surgery during pregnancy was evaluated in analysis of a large inpatient database.

SUMMARY

Identification of hypothyroidism during pregnancy continues to be challenging due to the need for well established trimester-specific normal ranges. Physicians may reassure patients about the effects of radioactive iodine therapy on fertility, although men may wish to cryopreserve sperm prior to treatment. Thyroid surgery during pregnancy was associated with a two-fold increased risk of surgical complications.

A categorical structure-activity relationship analysis of the developmental toxicity of antithyroid drugs

The choice of therapeutic strategies for hyperthyroidism during pregnancy is limited. Surgery and radioiodine are typically avoided, leaving propylthiouracil and methimazole in the US. Carbimazole, a metabolic precursor of methimazole, is available in some countries outside of the US. In the US propylthiouracil is recommended because of concern about developmental toxicity from methimazole and carbimazole. Despite this recommendation, the data on developmental toxicity of all three agents are extremely limited and insufficient to support a policy given the broad use of methimazole and carbimazole around the world. In the absence of new human or animal data we describe the development of a new structure-activity relationship (SAR) model for developmental toxicity using the cat-SAR expert system. The SAR model was developed from data for 323 compounds evaluated for human developmental toxicity with 130 categorized as developmental toxicants and 193 as nontoxicants. Model cross-validation yielded a concordance between observed and predicted results between 79% to 81%. Based on this model, propylthiouracil, methimazole, and carbimazole were observed to share some structural features relating to human developmental toxicity. Thus given the need to treat women with Graves's disease during pregnancy, new molecules with minimized risk for developmental toxicity are needed. To help meet this challenge, the cat-SAR method would be a useful in screening new drug candidates for developmental toxicity as well as for investigating their mechanism of action.