Birth weight in children with birth defects

Season, household registry and isolated birth defects: a population-based case-control study in Danyang, China

BACKGROUND

A birth population-based study was conducted in Danyang, Jiangsu Province, to evaluate major birth defects in emerging regions in China with similar maternal and neonatal care conditions.

METHODS

We conducted a population-based study in a cohort of infants born in Danyang from 2014 to 2021, including 55 709 perinatal infants. Four categories of isolated birth defects were defined as cases: congenital heart defects (CHDs; n=2138), polydactyly (n=145), cleft lip with or without palate (CL/P; n=76) and accessory auricles (n=93). Infants with congenital malformations were identified by the Chinese Birth Defects Monitoring Network.

RESULTS

Compared with autumn, conception in spring (OR=1.31 [1.16-1.48]) and winter (OR=1.39 [1.23-1.58]) was associated with an increased risk of CHD. Increased risk of CHD, CL/P and accessory auricles was significantly associated with non-local registered residence (OR=1.17 [1.07-1.28], OR=2.73 [1.52-4.88] and OR=2.11 [1.20-3.71], respectively). Individuals of Han nationality were less likely to have polydactyly (OR=0.23 [0.05-0.98]).

CONCLUSIONS

The season of pregnancy was significantly associated with CHDs. Offspring of mothers with non-local registered hometown had greater risks of CHDs, CL/P and accessory auricles.

Prepregnancy overweight and obesity as risk factors for birth defects: a cross-sectional study over a 30-year period

Overweight and obesity are public health problems worldwide despite being modifiable conditions. The association between birth defects and pregestational maternal body mass index is not entirely clear. We aimed to assess the prevalence and estimate the risk of birth defects related to pregestational body mass index and other maternal factors. We explored a 30-year time series database in a cross-section study. We analysed 40,217 cases, among them 2.8% had birth defects. Bivariate analysis showed a higher prevalence of birth defects with increased pre-pregnancy body mass index and in extremes of maternal age, white skin colour, and primiparity. Multivariable logistic regression showed a higher chance of birth defects in women with pre-pregnancy overweight/obesity (OR:1.19 [CI95%:1.01-1.41]), maternal age ≥ 40 years (OR:1.68 [CI95%:1.11-2.54]), and white skin colour (OR:1.44 [CI95%:1.19-1.75]). Maternal weight is a modifiable risk factor that must be considered and addressed in preconception counselling to minimise possible deleterious effects on embryogenesis.IMPACT STATEMENTWhat is already known on this subject? Previous studies have linked some maternal factors with birth defects. However, the association with prepregnancy maternal body mass index is not clear.What do the results of this study add? Our findings provide support for the association of prepregnancy maternal overweight and obesity with birth defects and highlight that BMI is a modified risk factor.What are the implications of these findings for clinical practice and/or further research? Maternal body mass index is a modifiable risk factor, highlighting the importance of preconception counselling for the prevention and possible reduction of factors that increase the risk of birth defects.

Maternal arsenic exposure, arsenic methylation efficiency, and birth outcomes in the Biomarkers of Exposure to ARsenic (BEAR) pregnancy cohort in Mexico

BACKGROUND

Exposure to inorganic arsenic (iAs) from drinking water is a global public health problem, yet much remains unknown about the extent of exposure in susceptible populations.

OBJECTIVES

We aimed to establish the Biomarkers of Exposure to ARsenic (BEAR) prospective pregnancy cohort in Gómez Palacio, Mexico, to better understand the effects of iAs exposure on pregnant women and their children.

METHODS

Two hundred pregnant women were recruited for this study. Concentrations of iAs in drinking water (DW-iAs) and maternal urinary concentrations of iAs and its monomethylated and dimethylated metabolites (MMAs and DMAs, respectively) were determined. Birth outcomes were analyzed for their relationship to DW-iAs and to the concentrations and proportions of maternal urinary arsenicals.

RESULTS

DW-iAs for the study subjects ranged from < 0.5 to 236 μg As/L. More than half of the women (53%) had DW-iAs that exceeded the World Health Organization's recommended guideline of 10 μg As/L. DW-iAs was significantly associated with the sum of the urinary arsenicals (U-tAs). Maternal urinary concentrations of MMAs were negatively associated with newborn birth weight and gestational age. Maternal urinary concentrations of iAs were associated with lower mean gestational age and newborn length.

CONCLUSIONS

Biomonitoring results demonstrate that pregnant women in Gómez Palacio are exposed to potentially harmful levels of DW-iAs. The data support a relationship between iAs metabolism in pregnant women and adverse birth outcomes. The results underscore the risks associated with iAs exposure in vulnerable populations.

Socioeconomic status accounts for rapidly increasing geographic variation in the incidence of poor fetal growth

Fetal growth is an important risk factor for infant morbidity and mortality. In turn, socioeconomic status is a key predictor of fetal growth; however, other sociodemographic factors and environmental effects may also be important. This study modelled geographic variation in poor fetal growth after accounting for socioeconomic status, with a fixed effect for socioeconomic status and a combination of spatially-correlated and spatially-uncorrelated random effects. The dataset comprised 88,246 liveborn singletons, aggregated within suburbs in Perth, Western Australia. Low socioeconomic status was strongly associated with an increased risk of poor fetal growth. An increase in geographic variation of poor fetal growth from 1999–2001 (interquartile odds ratio among suburbs = 1.20) to 2004–2006 (interquartile odds ratio = 1.40) indicated a widening risk disparity by socioeconomic status. Low levels of residual spatial patterns strengthen the case for targeting policies and practices in areas of low socioeconomic status for improved outcomes. This study indicates an alarming increase in geographic inequalities in poor fetal growth in Perth which warrants further research into the specific aspects of socioeconomic status that act as risk factors.

Congenital non-central nervous system malformations in cerebral palsy: a distinct subset?

AIM

The aim of this article was to identify and contrast the subset of children with cerebral palsy (CP) and non-central nervous system (CNS) congenital malformations with children with CP but no coexisting non-CNS congenital malformations.

METHOD

A population-based regional comprehensive CP registry was used to identify children with CP who had non-CNS congenital malformations (n = 34; 19 males, 15 females; 22 classified as Gross Motor Function Classification System [GMFCS] levels I-III, 12 as GMFCS level IV or V). Their clinical features were then compared with other children with CP without non-CNS congenital malformations (n = 207; 115 males, 92 females; 138 classified as GMFCS levels I-III, 69 as GMFCS level IV or V).

RESULTS

Children with CP and non-CNS congenital malformations did not differ from those without in terms of neurological subtype distribution or functional severity, as measured by the GMFCS. Also, there was no association with previous maternal infections (i.e. toxoplasmosis, rubella, cytomegalovirus, herpes simplex virus 2 [TORCH]), maternal fever, use of illicit substances, asphyxia, neonatal encephalopathy, intraventricular haemorrhage, or septicaemia. The incidence of comorbidities such as convulsions, communication difficulties, gavage feeding, cortical blindness, and auditory impairment was not higher in this subgroup.

INTERPRETATION

The incidence of congenital non-CNS malformations among children with CP is appreciable. Children with these non-CNS malformations do not appear to differ from other children with CP regarding neurological subtype, functional severity, and comorbidities, or maternal or obstetrical factors. Thus, the specific presence of a non-CNS congenital malformation does not appear to assist the practitioner in the management or understanding of a child's CP.