Prenatal Exposure to Fever and Infections and Academic Performance: A Multilevel Analysis

Exploring the relationships between pathogen-specific prenatal infections requiring inpatient admission and domains of offspring behaviour at age 5

BACKGROUND

Research exploring the relationship between prenatal infection and child behavioural outcomes would benefit from further studies utilising full-population samples with the scale to investigate specific infections and to employ robust designs. We tested the association among several common infections requiring inpatient admission during and after pregnancy with a range of childhood behavioural outcomes, to determine whether any negative impact was specific to the period of foetal development.

METHODS

The sample included all mother-offspring pairs from the Australian state of New South Wales (NSW) for whom the child commenced their first year of full-time schooling in 2009 (~age 5 years; n = 77,302 offspring), with records linked across four health administrative data sets including the NSW perinatal data collection (PDC), the NSW admitted patient data collection (APDC) and the NSW component of the 2009 Australian Early Development Census (AEDC). Multivariable linear regression was used to test associations between a number of infections requiring inpatient admission during and after pregnancy with a range of teacher assessed behavioural outcomes.

RESULTS

Associations specific to the prenatal period were only found for streptococcus A although this would need to be reproduced in external samples given the low prevalence. Otherwise, 12 out of 15 selected infections either showed no association prenatally or also demonstrated associations in the 12 months after pregnancy. For example, prenatal hepatitis C, influenza and urinary E. coli infections were associated with lower scores of several domains of childhood behaviour, but even stronger associations were found when these same maternal infections occurred after pregnancy.

CONCLUSIONS

The prenatal infections we tested appeared not to impact childhood behaviour by altering foetal neurodevelopment. Rather, the strong associations we found among infections occurring during and after pregnancy point to either residual socioeconomic/lifestyle factors or a shared familial/genetic liability between infections and behavioural problems.

Viral infections in pregnancy and impact on offspring neurodevelopment: mechanisms and lessons learned

Pregnant individuals with viral illness may experience significant morbidity and have higher rates of pregnancy and neonatal complications. With the growing number of viral infections and new viral pandemics, it is important to examine the effects of infection during pregnancy on both the gestational parent and the offspring. Febrile illness and inflammation during pregnancy are correlated with risk for autism, attention deficit/hyperactivity disorder, and developmental delay in the offspring in human and animal models. Historical viral epidemics had limited follow-up of the offspring of affected pregnancies. Infants exposed to seasonal influenza and the 2009 H1N1 influenza virus experienced increased risks of congenital malformations and neuropsychiatric conditions. Zika virus exposure in utero can lead to a spectrum of abnormalities, ranging from severe microcephaly to neurodevelopmental delays which may appear later in childhood and in the absence of Zika-related birth defects. Vertical infection with severe acute respiratory syndrome coronavirus-2 has occurred rarely, but there appears to be a risk for developmental delays in the infants with antenatal exposure. Determining how illness from infection during pregnancy and specific viral pathogens can affect pregnancy and neurodevelopmental outcomes of offspring can better prepare the community to care for these children as they grow. IMPACT: Viral infections have impacted pregnant people and their offspring throughout history. Antenatal exposure to maternal fever and inflammation may increase risk of developmental and neurobehavioral disorders in infants and children. The recent SARS-CoV-2 pandemic stresses the importance of longitudinal studies to follow pregnancies and offspring neurodevelopment.

Utility of data from the Danish National School Test Program for health research purposes: Content and associations with sociodemographic factors and higher education

The Danish National School Test Program is a set of nationwide tests performed annually since 2010 in all public schools in Denmark. To assess the utility of this data resource for health research purposes, we examined the association of school test performance with demographic and socioeconomic characteristics as well as correlations with ninth-grade exams and higher educational attainment. This nationwide descriptive register-based study includes children born between 1994 and 2010 who lived in Denmark at the age of six years. Norm-based test scores (range 1-100, higher scores indicate better performance) in reading (Danish) and mathematics from the Danish National School Test Program were obtained for children aged 6-16 attending public schools in Denmark from 2010 to 2019. Population registers were used to identify relevant demographic and socioeconomic variables. Mean test scores by demographic and socioeconomic variables were estimated using linear regression models. Among the full Danish population of 1,137,290 children (51.3% male), 960,450 (84.5%) children attended public schools. There were 885,360 children who completed one or more tests in reading or mathematics (test participation was 77.8% for the entire population, and 92.1% for children in public schools). Mean test scores varied by demographic and socioeconomic characteristics, most notably with education and labour market affiliation of parents. For every 1-point decrease in the test scores, there was a 0.95% (95% CI: 0.93%; 0.97%) lower probability of scoring B or higher in the ninth-grade exam and a 1.03% (95% CI: 1.00%; 1.05%) lower probability of completing high school within five years after graduating from lower secondary school. In this study of schoolchildren in Denmark, demographic and socioeconomic characteristics were associated with test scores from the Danish National School Test Program. Performance in school tests correlated closely with later educational attainment, suggesting that these early measures of school performance are good markers of subsequent academic potential.

Cognitive impairment in schizophrenia: aetiology, pathophysiology, and treatment

Cognitive deficits are a core feature of schizophrenia, account for much of the impaired functioning associated with the disorder and are not responsive to existing treatments. In this review, we first describe the clinical presentation and natural history of these deficits. We then consider aetiological factors, highlighting how a range of similar genetic and environmental factors are associated with both cognitive function and schizophrenia. We then review the pathophysiological mechanisms thought to underlie cognitive symptoms, including the role of dopamine, cholinergic signalling and the balance between GABAergic interneurons and glutamatergic pyramidal cells. Finally, we review the clinical management of cognitive impairments and candidate novel treatments.

Fever during pregnancy as a risk factor for neurodevelopmental disorders: results from a systematic review and meta-analysis

BACKGROUND

Fever during pregnancy is a relatively common and most often trivial event. However, under specific conditions, it could affect significantly fetal brain development. Few studies, with inconsistent results, investigated whether fever, regardless the pathogen, could represent a risk factor for neurodevelopmental disorders (NDD) in the offspring. We aimed to explore further this question by performing a systematic review and meta-analysis.

METHODS

Peer-reviewed studies exploring the occurrence of NDD in offspring after a fetal exposure to maternal fever were included. We specifically considered the impact of fever severity and duration, taking into consideration some confounding variables such as the use of antipyretic during pregnancy, the trimester in which the fever arose, the maternal age or smoking at time of gestation. MEDLINE, EMBASE, PsycINFO, Cochrane and Web of Science were searched without language restriction. PRISMA recommendations were followed. Odds ratio (OR) were pooled using random-effects meta-analysis. Heterogeneity in effect size across studies was studied using random-effects meta-regression analysis. (PROSPERO CRD42020182801).

RESULTS

We finally considered ten studies gathering a total of 10,304 children with NDD. Among them, 1394 were exposed to fever during pregnancy. The selected studies were divided into 5 case-control studies and 5 cohort studies. Maternal exposure to fever during pregnancy increased the risk of NDD in offspring with an OR of 1.24 [95% CI: 1.12-1.38]. Secondary analysis revealed an increased risk for NDD when fever occurred during the first trimester of gestation [OR 1.13-95% CI: 1.02-1.26].

LIMITATIONS

We excluded studies that considered infections with no evidence of fever. Another potential limitation may be the possible heterogeneity between study designs (cohorts and case-control).

CONCLUSION

Additional evidence supported the association between fever during pregnancy and increased risk for NDD in offspring. Careful monitoring should be considered for children born from mothers with a febrile episode during pregnancy (specifically during the first trimester).

Association of Rheumatoid Arthritis in Pregnancy With School Performance of Offspring: A Danish Nationwide Register-Based Study

OBJECTIVE

To examine the overall cognitive development of children exposed to maternal rheumatoid arthritis (RA) in utero by comparing their school test scores to those of their peers.

METHODS

Children born in Denmark during 1995-2008 and listed in the National School Test Register were included (n = 738,862). Children exposed to maternal RA were identified through linkage of national registers. In separate analyses, exposure was subdivided according to maternal serostatus. Preclinical maternal RA was included as a separate exposure. The Danish national school tests are mandatory standardized tests. Results from all reading tests (grades 2, 4, 6, and 8) and mathematics tests (grades 3 and 6) from 2010-2017 were included. Test scores were compared according to maternal RA exposure for each test separately using linear regressions.

RESULTS

We identified 934 children exposed to maternal RA in utero. There were no differences in reading test scores between maternal RA exposed and unexposed children. RA exposed children scored poorer in both mathematics tests (adjusted differences of mean score -0.14 SD (95% confidence interval [95% CI] -0.23, -0.06) and -0.16 SD (95% CI -0.26, -0.07). There was no appreciable difference between children by maternal RA serostatus. Children exposed to preclinical RA (n = 589) showed the same pattern of performance as children exposed to RA.

CONCLUSION

RA-exposed children scored slightly poorer in mathematics tests but performed as well as their unexposed peers in the reading tests. The results do not suggest that RA in pregnancy has a major impact on offspring school performance.

Effect of Diarrheal Illness During Pregnancy on Adverse Birth Outcomes in Nepal

Background

Adverse birth outcomes, including low birthweight, small for gestational age (SGA), and preterm birth, contribute to 60%–80% of infant mortality worldwide. Little published data exist on the association between diarrhea during pregnancy and adverse birth outcomes.

Methods

Data were used from 2 community-based, prospective randomized trials of maternal influenza immunization during pregnancy conducted in rural Nepal from 2011 to 2014. Diarrheal illnesses were identified through longitudinal household-based weekly symptom surveillance. Diarrhea episodes were defined as at least 3 watery bowel movements per day for 1 or more days with 7 diarrhea-free days between episodes. The Poisson and log-binomial regression were performed to evaluate baseline characteristics and association between diarrhea during pregnancy and adverse birth outcomes.

Results

A total of 527 of 3693 women in the study (14.3%) experienced diarrhea during pregnancy. Women with diarrhea had a median of 1 episode of diarrhea (interquartile range [IQR], 1–2 episodes) and 2 cumulative days of diarrhea (IQR, 1–3 days). Of women with diarrhea, 85 (16.1%) sought medical care. In crude and adjusted analyses, women with diarrhea during pregnancy were more likely to have SGA infants (42.6% vs 36.8%; adjusted risk ratio = 1.20; 95% confidence interval, 1.06–1.36; P = .005). Birthweight and preterm birth incidence did not substantially differ between women with diarrhea during pregnancy and those without.

Conclusions

Diarrheal illness during pregnancy was associated with a higher risk of SGA infants in this rural South Asian population. Interventions to reduce the burden of diarrheal illness during pregnancy may have an impact on SGA births in resource-limited settings.