Comprehensive assessment of the associations between maternal diabetes and structural birth defects in offspring: a phenome-wide association study

Maternal pre-pregnancy diabetes and risk of all-cause and cause-specific infant mortality

BACKGROUND

Maternal pre-pregnancy diabetes is associated with a higher risk of adverse pregnancy outcomes. Few large, cohort studies have assessed associations with a wide large range of causes of infant death.

METHODS

This retrospective cohort study included all singleton live births to women aged 18-49 years in the US National Vital Statistics System from 2011 to 2020. Multivariable Poisson regression models were used to estimate adjusted relative risks (RRs) with 95% confidence intervals (CIs) for all-cause and cause-specific infant mortality.

RESULTS

Of 34  918  803 pregnant women with singleton live births, 302  823 had pre-pregnancy diabetes with 3585 corresponding infant deaths [estimated mortality rate per 10 000 infants with 95% CI was 78.60 (75.96-81.25)] compared with 34  615  980 without pre-pregnancy diabetes and 171  989 corresponding infant deaths [42.63 (42.41-42.86)]. The adjusted RR (95% CI) of pre-pregnancy diabetes compared with no pre-pregnancy diabetes was 1.84 (1.78-1.91) for infant death, 1.89 (1.81-1.97) for neonatal death, 1.85 (1.77-1.94) for early neonatal death, 2.04 (1.87-2.23) for late neonatal death, and 1.75 (1.65-1.86) for postneonatal deaths. The association was stronger (RR: 2.03, 95% CI: 1.88-2.20) with lower maternal age (<25 years) than with higher maternal age (≥40 years) (RR: 1.44, 95% CI: 1.28-1.63). Associations varied across maternal race, smoking, and body mass index. Significantly increased risk was observed for 48 out of 73 specific causes of death.

CONCLUSION

Our findings confirm that maternal pre-pregnancy diabetes is an important risk factor for infant death, encompassing a wide range of causes of death, and suggest that these effects may be systemic given the large number of specific causes of death affected.

Systematic Review and Meta-analysis of Prenatal Risk Factors for Congenital Heart Disease: Part 1, Maternal Chronic Diseases and Parental Exposures

BACKGROUND

There is considerable heterogeneity in studies on prenatal risk factors for congenital heart diseases (CHDs). We performed a meta-analysis of all nongenetic factors of CHDs. This report presents results of factors related to maternal chronic diseases and parental exposures.

METHODS

A systematic search encompassing concepts of CHD and risk factors was used, using the following inclusion criteria: (1) original peer-reviewed articles, (2) quantifying the effects of risk factors for CHDs, (3) between 1989 and 2022. Pooled odds ratios (ORs) and 95% confidence interval (CI) were calculated using a random-effect model.

RESULTS

Inclusion criteria were met for 170 studies. There was an association between being overweight or obese and CHDs (OR, 1.26; 95% CI, 1.15-1.37), with a dose-effect relationship. Pregestational diabetes (PGDM) was associated with CHDs (OR, 3.51; 95% CI, 2.86-4.3), without difference between type 1 and type 2 PGDM. The effect size of gestational diabetes was less than that of PGDM (OR, 1.38; 95% CI, 1.18-1.61). There was an association between CHDs and pre-eclampsia (OR, 2.01; 95% CI, 1.32-3.05), paternal smoking (OR, 1.32; 95% CI, 1.03-1.70), and alcohol use (OR, 1.50; 95% CI, 1.08-2.08). A smaller association was found with maternal smoking and advanced maternal age.

CONCLUSIONS

There exists robust evidence for increased risk of CHD in the presence of obesity, maternal diabetes, maternal smoking, and increased maternal age. The effect sizes were relatively modest, except for PGDM. The robustness of the evidence decreased when CHDs were divided into subgroups or when the analyses were restricted to severe CHDs.

Maternal Gestational Diabetes Mellitus and Congenital Heart Disease in Offspring: A Meta-Analysis

Maternal diabetes has been related to an increased risk of congenital heart disease (CHD) in offspring. However, inconsistent results were retrieved for studies evaluating the association between gestational diabetes mellitus (GDM) and CHD in offspring. We therefore performed a systematic review and meta-analysis for comprehensive investigation. Observational studies were identified by searching PubMed, Embase, and Web of Science according to the aim of the meta-analysis. A randomized-effects model was used to pool the data by incorporating the influence of potential heterogeneity. Twenty-three observational studies, involving 46953078 mother-child pairs, were available for the meta-analysis. Among them, 2131800 mothers were diagnosed as GDM and 214379 newborns had CHD. Overall, maternal GDM was associated with a higher incidence of CHD in offspring [odds ratio (OR): 1.32, 95% confidence interval (CI): 1.21 to 1.45, p<0.001; I2=62%]. Sensitivity analysis limited to studies with adjustment of maternal age and other potential confounding factors showed similar results (OR: 1.40, 95% CI: 1.30 to 1.51, p<0.001; I2=47%). Subgroup analysis suggested that the association between maternal GDM and CHD in offspring was not significantly affected by methods for diagnosis of GDM, methods for confirmation of CHD, or study quality scores (p for subgroup difference all>0.05). Subsequent analysis according to types of CHD showed that maternal GDM was associated with higher risks of atrial septal defect, ventricular septal defect, and Tetralogy of Fallot. Maternal GDM may be associated with a higher risk of CHD in offspring.

Newborn screening analytes and structural birth defects among 27,000 newborns

BACKGROUND

Emerging evidence suggests newborn screening analytes may yield insights into the etiologies of birth defects, yet no effort has evaluated associations between a range of newborn screening analytes and birth defects.

METHODS

This population-based study pooled statewide data on birth defects, birth certificates, and newborn screening analytes from Texas occurring between January 1, 2007 and December 31, 2009. Associations between a panel of thirty-six newborn screening analytes, collected by the statewide Texas Newborn Screening Program, and the presence of a birth defect, defined as at least one of 39 birth defects diagnoses recorded by the Texas Birth Defects Registry, were assessed using regression analysis.

FINDINGS

Of the 27,643 births identified, 20,205 had at least one of the 39 birth defects of interest (cases) as identified by the Texas Birth Defects Registry, while 7,438 did not have a birth defect (controls). Among 1,404 analyte-birth defect associations evaluated, 377 were significant in replication analysis. Analytes most consistently associated with birth defects included the phenylalanine/tyrosine ratio (N = 29 birth defects), tyrosine (N = 28 birth defects), and thyroxine (N = 25 birth defects). Birth defects most frequently associated with a range of analytes included gastroschisis (N = 29 analytes), several cardiovascular defects (N = 26 analytes), and spina bifida (N = 23 analytes).

CONCLUSIONS

Several significant and novel associations were observed between newborn screening analytes and birth defects. While some findings could be consequences of the defects themselves or to the care provided to infants with these defects, these findings could help to elucidate mechanisms underlying the etiology of some birth defects.

Prevalence of congenital anomalies according to maternal race and ethnicity, Texas, 1999-2018

BACKGROUND

Few studies of congenital anomalies provide prevalence estimates stratified by maternal race/ethnicity. We sought to determine whether the prevalence of a broad spectrum of anomalies varies among offspring of women from different race/ethnic groups.

METHODS

We obtained information on cases with anomalies from the population-based Texas Birth Defects Registry, and denominator data on livebirths among Texas residents during 1999-2018 from the Texas Center for Health Statistics. We estimated the prevalence ratio (PR) and 95% confidence interval (CI) of N = 145 anomalies among offspring of Hispanic and non-Hispanic Black relative to non-Hispanic White women using Poisson regression, adjusting for maternal age, education, body mass index, and previous livebirths. We performed a two-stage analysis with a Bonferroni-adjusted p < 1.7 × 10-4 in the initial screening phase to identify anomalies with statistically significant variation.

RESULTS

There were 7,698,768 livebirths and 1,187,385 anomalies diagnosed in 368,393 cases. The prevalence of any monitored congenital anomaly was similar among offspring of non-Hispanic White (referent), non-Hispanic Black (PR 0.98, CI 0.96-1.00), and Hispanic (PR 0.95, CI 0.93-0.96) women. We observed statistically significant racial/ethnic variation for 42 anomalies. Marked differences were observed when comparing offspring of non-Hispanic Black to non-Hispanic White women with respect to polydactyly (PR 4.38, CI 4.07-4.72), pyloric stenosis (PR 0.34, CI 0.29-0.40), and aortic valve atresia/stenosis (PR 0.51, CI 0.36-0.72).

CONCLUSIONS

Birth prevalence of many major congenital anomalies varies by maternal race and ethnicity. While the reasons for these differences are likely multifactorial, a thorough understanding of racial and ethnic disparities is useful to stimulate etiologic research.

Gestational diabetes is associated with the risk of offspring's congenital anomalies: a register-based cohort study

BACKGROUND

Gestational diabetes mellitus (GDM) is a common pregnancy-related disorder and a well-known risk factor for adverse pregnancy outcomes. There are conflicting findings on the association of GDM with the risk of congenital anomalies (CAs) in offspring. In this study, we aimed to determine study whether maternal GDM is associated with an increased risk of major CAs in offspring.

METHODS

This Finnish Gestational Diabetes (FinnGeDi) register-based study included 6,597 women with singleton pregnancies and a diagnosis of GDM and 51,981 singleton controls with no diabetes identified from the Finnish Medical Birth Register (MBR) in 2009. Data from MBR were combined in this study with the Register of Congenital Malformations, which includes the data of CAs. We used logistic regression to calculate odds ratios (OR) for CAs, together with their 95% confidence intervals (CIs), adjusting for maternal age, parity, pre-pregnancy body mass index (BMI), and maternal smoking status.

RESULTS

The risk of major CAs was higher in the GDM-exposed (n = 336, 5.09%) than in the non-exposed group (n = 2,255, 4.33%) (OR: 1.18, 95% CI: 1.05-1.33, p = 0.005). The adjusted OR (aOR) was 1.14 (95% CI: 1.00-1.30, p = 0.047). There was a higher overall prevalence of CAs, particularly chromosomal abnormalities (0.52% vs. 0.21%), in the GDM-exposed group (OR: 2.49, 95% Cl: 1.69-3.66, p < 0.001). The aOR was 1.93 (95% Cl: 1.25-2.99, p = 0.003).

CONCLUSIONS

Offspring exposed to GDM have a higher prevalence of major CAs. Of note, risk factors other than GDM, such as older maternal age and a higher pre-pregnancy BMI, diminished the between group differences in the prevalence of major CAs. Nevertheless, our findings suggest that offspring exposed to maternal GDM are more likely to be diagnosed with a chromosomal abnormality, independent of maternal age, parity, pre-pregnancy BMI, and smoking.

Current perspectives in hypospadias research: A scoping review of articles published in 2021 (Review)

Hundreds of papers are written about hypospadias every year referring to all aspects of the pathology, being one of the most common congenital malformations. The present study conducted a scoping review of articles published in 2021 to present the main issues and summarize current perspectives and achievements in the field. It searched for the keyword 'hypospadias' in the three most popular databases (PubMed, Scopus and Web of Science). After the analysis of the publications, they were categorized into different domains. The present review was performed respecting the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA ScR) guidelines. A total of 284 articles were included. These were published in 142 different journals. The most accessed was the Journal of Paediatric Urology with 54 articles. The main identified domains were related to surgical techniques, postoperative care, complications, anesthesia, anatomical factors, genetics, environmental factors, endocrinology, associated malformations, questionnaires and recommendations, management, biological materials, animal models, retrospective studies of centers, social media, bibliometrics, small gestational age, neoplasm, or fertility. Promising modifications of existing surgical techniques were presented with improved outcomes for both the proximal and distal types of hypospadias. Relevant anatomical and etiological, and also genetic factors were clarified. Aspects of the peri- and postoperative management referring to the antibiotherapy, analgesia, dressing techniques, and the future use of novel bioengineering agents to prevent, reduce or treat the occurring complications were discussed.

Temporal trends in prevalence and infant mortality of birth defects in Brazil, from 2001 to 2018

Congenital anomalies (CA) are a relevant problem for global public health, affecting about 3% to 6% of newborns worldwide. In Brazil, these are the second main cause of infant mortality. Thus, extensive studies are needed to demonstrate the impact of these anomalies on births and deaths. The present study describes the temporal trends of prevalence and infant mortality due to CA among live births in Brazil and regions, from 2001 to 2018, using the related data between the Live Birth Information System (SINASC, acronym in Portuguese) and the Mortality Information System (SIM, acronym in Portuguese). The prevalence and infant mortality due to CA has increased in Brazil and in most regions, especially in the Northeast and North. CAs in the musculoskeletal system were the most frequent at birth (29.8/10,000 live births), followed by those in the circulatory system (12.7/10,000 live births), which represented the primary cause of death in this group. The applied linkage technique made it possible to correct the national prevalence of CA by 17.9% during the analyzed period, after retrieving the anomalies reported in SIM, thereby proving to be a good tool to improve the quality of information on anomalies in Brazil.

Bronchopulmonary dysplasia is associated with polyhydramnios in a scan for novel perinatal risk factors

BACKGROUND

The pathogenesis of bronchopulmonary dysplasia (BPD) is multifactorial, and there are limited data about prenatal exposures and risk of BPD.

STUDY DESIGN

Our study performed parallel analyses using a logistic regression model in a cohort of 4527 infants with data from a curated registry and using a phenome wide association study (PheWAS) based on ICD9/10-based phecodes. We examined 20 prenatal exposures from a neonatal intensive care unit (NICU) curated registry database related to pregnancy and maternal health as well as 94 maternal diagnosis phecodes with a PheWAS analysis.

RESULT

In both the curated registry and PheWAS analyses, polyhydramnios was associated with an increased risk of BPD (OR 5.70, 95% CI 2.78-11.44, p = 1.37 × 10-6).

CONCLUSION

Our data suggest that polyhydramnios may be a clinical indicator of premature infants at increased risk for bronchopulmonary dysplasia. Combining curated registry data with PheWAS analysis creates a valuable tool to generate hypotheses.

IMPACT

Polyhydramnios was significantly associated with bronchopulmonary dysplasia in both a curated registry and by ICD coding analysis with a phenome wide association study (PheWAS). Preterm polyhydramnios may be a clinical indicator of infants at increased risk for developing bronchopulmonary dysplasia after preterm birth. Combining curated registry with PheWAS analysis creates a valuable tool to generate hypotheses about perinatal risk factors and morbidities associated with preterm birth.

Metabolic Characteristics of Gestational Diabetes Mellitus and the Effects on Pregnancy Outcomes

OBJECTIVE

To describe the metabolic characteristics of gestational diabetes mellitus (GDM) and assess their effects on perinatal outcomes.

METHODS

A two-center nested case‒control study was designed, including 192 pregnant women with GDM and 191 pregnant women with normal glucose tolerance (NGT). Serum glucose and insulin concentrations based upon the 75 g oral glucose tolerance test (OGTT) were measured. Several indices were calculated to describe the metabolic characteristics of the subjects. The relationship between glucose metabolism parameters and pregnancy outcomes was evaluated using stepwise linear regression and binary logistic regression.

RESULTS

Compared with the NGT group, the GDM group showed significantly higher fasting and postprandial glucose parameters but significantly lower fasting and postprandial insulin responses. Meanwhile, the GDM group had significantly lower HOMA-β, DI and ISI_Matsuda but comparable HOMA-IR. The IFG subgroup showed significantly lower FINS/FPG only, while the IGT and IFSG subgroups showed deficiency in both fasting and postprandial insulin response. The IFSG subgroup had the highest glucose parameters and the lowest insulin parameters, as well as significantly lower ISI_Matsuda and HOMA-β than the NGT group. FPG had a significant effect on infants' birth weight, and 1hPG and FINS/FPG had a significant effect on delivery gestational age. AUC-INS, IGI₆₀ and DI were related to premature delivery risk after adjusting for confounders. The IFG subgroup of GDM was 2.319 times more likely to be subject to cesarean section than the NGT group. FPG, FINS/FPG, AUC-GLU, AUC-INS/AUC-GLU and HOMA-β were related to macrosomia risk.

CONCLUSION

Beta cell dysfunction rather than insulin resistance determines the occurrence of GDM in the central Chinese population. Women with predominant insulin secretion defects had a similar risk of adverse perinatal outcomes to women with NGT. Our study provided a basis for the selection of glucose metabolism monitoring indicators useful for the prevention of adverse perinatal outcomes.

Factors associated with nonsyndromic anotia and microtia, Texas, 1999-2014

BACKGROUND

Few risk factors have been identified for nonsyndromic anotia/microtia (A/M).

METHODS

We obtained data on cases and a reference population of all livebirths in Texas for 1999-2014 from the Texas Birth Defects Registry (TBDR) and Texas vital records. We estimated prevalence ratios (PRs) and 95% confidence intervals (CIs) for A/M (any, isolated, nonisolated, unilateral, and bilateral) using Poisson regression. We evaluated trends in prevalence rates using Joinpoint regression.

RESULTS

We identified 1,322 cases, of whom 982 (74.3%) had isolated and 1,175 (88.9%) had unilateral A/M. Prevalence was increased among males (PR: 1.3, 95% CI: 1.2-1.4), offspring of women with less than high school education (PR: 1.3, 95% CI: 1.1-1.5), diabetes (PR: 2.0, 95% CI: 1.6-2.4), or age 30-39 versus 20-29 years (PR: 1.2, 95% CI: 1.0-1.3). The prevalence was decreased among offspring of non-Hispanic Black versus White women (PR: 0.6, 95% CI: 0.4-0.8) but increased among offspring of Hispanic women (PR: 2.9, 95% CI: 2.5-3.4) and non-Hispanic women of other races (PR: 1.7, 95% CI: 1.3-2.3). We observed similar results among cases with isolated and unilateral A/M. Sex disparities were not evident for nonisolated or bilateral phenotypes, nor did birth prevalence differ between offspring of non-Hispanic Black and non-Hispanic White women. Maternal diabetes was more strongly associated with nonisolated (PR: 4.5, 95% CI: 3.2-6.4) and bilateral A/M (PR: 5.0, 95% CI: 3.3-7.7). Crude prevalence rates increased throughout the study period (annual percent change: 1.82).

CONCLUSION

We identified differences in the prevalence of nonsyndromic A/M by maternal race/ethnicity, education, and age, which may be indicators of unidentified social/environmental risk factors.

Urban-rural residence and birth defects prevalence in Texas: a phenome-wide association study

BACKGROUND

Some assessments indicate the prevalence of certain birth defects varies by urban-rural status. We evaluated associations between urban-rural residence and a spectrum of birth defects, using a phenome-wide association study approach in Texas, a state with large urban centers and expansive rural areas.

METHODS

Data for birth defects and livebirths during 1999-2015 were obtained from the Texas Birth Defects Registry and the Center for Health Statistics. Maternal residence was classified as urban or rural, and prevalence ratios (PR) and 95% confidence intervals (CI) were calculated for any defect and 140 specific defects by Poisson regression.

RESULTS

Overall, birth defects were less frequent in rural compared to urban counties (PR = 0.88, 95% CI: 0.87-0.89). Twelve specific defects were less prevalent in rural counties, including ventricular septal defects (VSDs; PR = 0.76, 95% CI: 0.73-0.79) and hypospadias (PR = 0.86, 95% CI: 0.82-0.89). For some birth defects, including VSDs, there was evidence of decreasing prevalence with decreasing population size.

CONCLUSIONS

In our large population-based assessment, we demonstrated that several birth defects were less prevalent in rural counties, suggesting that characteristics of urban settings may be relevant to their etiologies, diagnosis, or surveillance. Further research is needed to identify specific exposures underlying these associations.

IMPACT

There are few studies of birth defects prevalence in urban versus rural settings. To address this, we investigated a comprehensive range of birth defects, including several rare defects that have not been previously studied, in a large and diverse population. We identified 12 structural birth defects that were less prevalent in rural areas. Findings suggest possible differential exposures among urban and rural women, and/or possible underdiagnosis of certain birth defects in rural areas. Findings highlight the need for further study of geographically referenced risk factors for birth defects, and of the completeness of birth defects ascertainment in rural areas.

A systematic review of maternal diabetes and congenital skeletal malformation

The magnitude of association of skeletal anomalies with maternal diabetes is not known. The systemic review was done to detect the frequency of congenital skeletal malformations with diabetes mellitus in pregnancy in the literature evidence of the past 50 years. Literature on maternal diabetes and skeletal malformation was searched by two independent authors by following PRISMA guidelines. Strict inclusion and exclusion criteria were followed. After quality assessment, 21 original articles were included. The frequency of congenital malformation, skeletal malformation was extracted from the included studies. 11,574 congenital anomalies were detected diabetic mothers. 1182 skeletal anomalies were noted in 20,11 552 diabetic mothers. The skeletal malformation was noted in 20.4% of total anomalies. The most common skeletal malformation was the defect of the spine (39.9%). The limb deficiency was found in 32.8% of the infants of diabetic mothers. The skeletal malformations were higher, that is, 24.6% in pre-gestational diabetes. The incidence of skeletal malformation from the evidence was 1.5% (range: 0.03-4.27%) in maternal diabetes. Pre-gestation diabetes is more frequently associated with skeletal malformations, which is 1.9% (range: 0.07-5.89%). The association of congenital malformations and skeletal malformations in diabetic pregnancy is significant and hence, effective management of diabetes in childbearing age is essential to reduce this incidence and related long-term morbidity.

Risks of specific congenital anomalies in offspring of women with diabetes: A systematic review and meta-analysis of population-based studies including over 80 million births

BACKGROUND

Pre-gestational diabetes mellitus (PGDM) has been known to be a risk factor for congenital heart defects (CHDs) for decades. However, the associations between maternal PGDM and gestational diabetes mellitus (GDM) and the risk of specific types of CHDs and congenital anomalies (CAs) in other systems remain under debate. We aimed to investigate type-specific CAs in offspring of women with diabetes and to examine the extent to which types of maternal diabetes are associated with increased risk of CAs in offspring.

METHODS AND FINDINGS

We searched PubMed and Embase from database inception to 15 October 2021 for population-based studies reporting on type-specific CAs in offspring born to women with PGDM (combined type 1 and 2) or GDM, with no limitation on language. Reviewers extracted data for relevant outcomes and performed random effects meta-analyses, subgroup analyses, and multivariable meta-regression. Risk of bias appraisal was performed using the Cochrane Risk of Bias Tool. This study was registered in PROSPERO (CRD42021229217). Primary outcomes were overall CAs and CHDs. Secondary outcomes were type-specific CAs. Overall, 59 population-based studies published from 1990 to 2021 with 80,437,056 participants met the inclusion criteria. Of the participants, 2,407,862 (3.0%) women had PGDM and 2,353,205 (2.9%) women had GDM. The meta-analyses showed increased risks of overall CAs/CHDs in offspring born to women with PGDM (for overall CAs, relative risk [RR] = 1.99, 95% CI 1.82 to 2.17, P < 0.001; for CHDs, RR = 3.46, 95% CI 2.77 to 4.32, P < 0.001) or GDM (for overall CAs, RR = 1.18, 95% CI 1.13 to 1.23, P < 0.001; for CHDs, RR = 1.50, 95% CI 1.38 to 1.64, P < 0.001). The results of the meta-regression analyses showed significant differences in RRs of CAs/CHDs in PGDM versus GDM (all P < 0.001). Of the 23 CA categories, excluding CHD-related categories, in offspring, maternal PGDM was associated with a significantly increased risk of CAs in 21 categories; the corresponding RRs ranged from 1.57 (for hypospadias, 95% CI 1.22 to 2.02) to 18.18 (for holoprosencephaly, 95% CI 4.03 to 82.06). Maternal GDM was associated with a small but significant increase in the risk of CAs in 9 categories; the corresponding RRs ranged from 1.14 (for limb reduction, 95% CI 1.06 to 1.23) to 5.70 (for heterotaxia, 95% CI 1.09 to 29.92). The main limitation of our analysis is that some high significant heterogeneity still persisted in both subgroup and sensitivity analyses.

CONCLUSIONS

In this study, we observed an increased rate of CAs in offspring of women with diabetes and noted the differences for PGDM versus GDM. The RRs of overall CAs and CHDs in offspring of women with PGDM were higher than those in offspring of women with GDM. Screening for diabetes in pregnant women may enable better glycemic control, and may enable identification of offspring at risk for CAs.

Targeted drug delivery for maternal and perinatal health: Challenges and opportunities

Pre-existing conditions at reproductive age, and complications arising during pregnancy can be detrimental to maternal and fetal health. Current therapies to combat obstetric disorders are limited due to the inherent complexity of pregnancy, and can have harmful effects on developing fetus. Emerging research shows intricate signaling between the cells from mother and fetus at maternal-fetal interface, providing unique opportunities for interventions specifically targeted to the mother, fetus, or placenta. Advancements in nanotechnology, stem-cell biology and gene therapy have resulted in target-specific treatments with promising results in pre-clinical maternal and fetal disorder models. Comprehensive understanding of the effect of physicochemical properties of delivery systems on their uptake, retention and accumulation across placenta will help in the better diagnosis and treatment of perinatal disorders. This review describes the factors leading to obstetric complications along with their effect on pregnancy outcomes, and discusses key targeted therapeutic strategies for addressing conditions related to maternal and fetal health.

Using Phecodes for Research with the Electronic Health Record: From PheWAS to PheRS

Electronic health records (EHRs) are a rich source of data for researchers, but extracting meaningful information out of this highly complex data source is challenging. Phecodes represent one strategy for defining phenotypes for research using EHR data. They are a high-throughput phenotyping tool based on ICD (International Classification of Diseases) codes that can be used to rapidly define the case/control status of thousands of clinically meaningful diseases and conditions. Phecodes were originally developed to conduct phenome-wide association studies to scan for phenotypic associations with common genetic variants. Since then, phecodes have been used to support a wide range of EHR-based phenotyping methods, including the phenotype risk score. This review aims to comprehensively describe the development, validation, and applications of phecodes and suggest some future directions for phecodes and high-throughput phenotyping.

Could Subtle Obstetrical Brachial Plexus Palsy Be Related to Unilateral B Glenoid Osteoarthritis?

Background: Several factors associated with B glenoid are also linked with obstetrical brachial plexus palsy (OBPP). The purpose of this observational study was to determine the incidence of OBPP risk factors in type B patients. Methods: A cohort of 154 patients (68% men, 187 shoulders) aged 63 ± 17 years with type B glenoids completed a questionnaire comprising history of perinatal characteristics related to OBPP. A literature review was performed following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) to estimate the incidence of OBPP risk factors in the general population. Results: Twenty-seven patients (18%) reported one or more perinatal OBPP risk factors, including shoulder dystocia (n = 4, 2.6%), macrosomia >4 kg (n = 5, 3.2%), breech delivery (n = 6, 3.9%), fetal distress (n = 8, 5.2%), maternal diabetes (n = 2, 1.3%), clavicular fracture (n = 2, 1.3%), and forceps delivery (n = 4, 2.6%). The comparison with the recent literature suggested that most perinatal OBPP risk factors were within the normal range, although the incidence of shoulder dystocia, forceps and vaginal breech deliveries exceeded the average rates. Conclusion: Perinatal factors related to OBPP did not occur in a higher frequency in patients with Walch type B OA compared to the general population, although some of them were in the high normal range.

A Comprehensive Assessment of the Associations Between Season of Conception and Birth Defects, Texas, 1999-2015

Birth defects prevalence may vary seasonally, but previous studies have focused on a few commonly occurring phenotypes. We performed a phenome-wide association study (PheWAS) in order to evaluate the associations between season of conception and a broad range of birth defects. Date of conception was estimated for all livebirths and birth defect cases in Texas from 1999-2015 using data from vital records, provided by the Texas Department of State Health Services Center for Health Statistics. Birth defects diagnoses were obtained from the Texas Birth Defects Registry, a statewide, active surveillance system. We estimated prevalence ratios (PRs) for phenotypes with ≥50 cases according to conception in spring (March-May), summer (June-August) or fall (September-November) relative to winter (December-February), using Poisson regression. Season of conception was associated with 5% of birth defects studied in models adjusted for maternal age, education, race/ethnicity, and number of previous livebirths. Specifically, summer conception was associated with any monitored birth defect (PR 1.03, 95% CI 1.02-1.04) and five specific phenotypes, most notably Hirschsprung disease (PR 1.46, 95% CI 1.22-1.75). These findings suggest that seasonally variable exposures influence the development of several birth defects and may assist in identifying novel environmental risk factors.