Evaluation of prenatal diabetes mellitus and other risk factors for craniofacial microsomia

Risk factors and characteristics of the birth of patients with craniofacial microsomia, a case-control study

BACKGROUND

Craniofacial microsomia (CM) is characterized by changes in the first and second branchial arches. It is a clinical condition whose etiology is still uncertain, but studies have shown that genetic, nutritional, and environmental factors can result in disorders of blastogenesis of the branchial arches. This study evaluates gestational aspects, focusing on possible risk factors associated with CM.

METHODS

This is a case-control study conducted with patients monitored at a medical genetics service and compared to a control group of patients without evidence of malformations, born in a mother and child hospital, both located in Porto Alegre, Southern Brazil. Mothers' data were obtained using questionnaires and by reviewing medical records. The sample consisted of 43 patients with CM (cases) and 129 patients without evidence of malformations (controls), paired by sex, totaling three controls for each case. Data analysis was performed using the two-tailed Fisher's exact test, Pearson's chi-square test, and the t-test.

RESULTS

We identified several factors associated with the development of CM, including the use of abortion methods by the mothers of these babies (p = .001), maternal diabetes (p = .009), advanced maternal age (p = .035), and a history of vaginal bleeding (p < .001). Furthermore, these patients exhibited a tendency to be born prematurely (p = .027), with low birth weight (p = .007), and lower Apgar scores (p = .003) when compared to healthy infants. Using a multivariate model, the use of abortion methods (p = .003) and vaginal bleeding (p = .032) remained independently associated with craniofacial microsomia.

CONCLUSIONS

We have identified several risk factors for the development of CM, including a propensity for premature birth, low birth weight, and respiratory difficulties. Additionally, women of advanced maternal age and/or those who used abortion methods and/or have diabetes have a higher risk of giving birth to a baby with CM. This information can be valuable in clinical practice, especially for the prevention of future cases.

Oculo-auriculo-vertebral spectrum: new genes and literature review on a complex disease

Oculo-auriculo-vertebral spectrum (OAVS) or Goldenhar syndrome is due to an abnormal development of first and second branchial arches derivatives during embryogenesis and is characterised by hemifacial microsomia associated with auricular, ocular and vertebral malformations. The clinical and genetic heterogeneity of this spectrum with incomplete penetrance and variable expressivity, render its molecular diagnosis difficult. Only a few recurrent CNVs and genes have been identified as causatives in this complex disorder so far. Prenatal environmental causal factors have also been hypothesised. However, most of the patients remain without aetiology. In this review, we aim at updating clinical diagnostic criteria and describing genetic and non-genetic aetiologies, animal models as well as novel diagnostic tools and surgical management, in order to help and improve clinical care and genetic counselling of these patients and their families.

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.

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

PURPOSE

Our objective was to comprehensively evaluate the risk of a broad range of birth defects among offspring of women with diabetes, overall and stratified by pregestational versus gestational diagnosis, using the phenome-wide association (PheWAS) methodology.

METHODS

We performed a registry linkage study of all live births (>6,500,000) and birth defects cases (>290,000) in Texas, 1999-2015. We ascertained diabetes from birth and fetal death certificates. We calculated prevalence rate ratios (PRR) for phenotypes with ≥10 cases among exposed offspring (n = 130).

RESULTS

Diabetes was associated with the prevalence of any defect (PRR 1.40, 95% confidence interval [CI] 1.38-1.42), multiple defects (PRR 1.86, 95% CI 1.81-1.91), and 60 specific phenotypes, including novel (hypospadias, mitral stenosis) and previously reported phenotypes (renal a-/dysgenesis, spinal anomalies). Pregestational diabetes was a stronger risk factor for any defect (PRR 2.00, 95% CI 1.93-2.07), multiple defects (PRR 3.27, 95% CI 3.11-3.44), and the 60 specific phenotypes evaluated. Gestational diabetes was associated with any defect (PRR 1.21, 95% CI 1.19-1.23) and 47 specific birth defects phenotypes, although associations were weaker than for pregestational diabetes.

CONCLUSIONS

The PheWAS is an efficient way to identify risk factors for disease using population-based registry data. Pregestational diabetes is associated with a broader range of phenotypes than previously reported. Because diabetes is diagnosed in 1% of women prior to pregnancy and 6%-9% during pregnancy, our results highlight a significant public health concern.