Prenatal Infection Research Articles

A microglia-containing cerebral organoid model to study early life immune challenges.

Prenatal infections and activation of the maternal immune system have been proposed to contribute to causing neurodevelopmental disorders (NDDs), chronic conditions often linked to brain abnormalities. Microglia are the resident immune cells of the brain and play a key role in neurodevelopment. Disruption of microglial functions can lead to brain abnormalities and increase the risk of developing NDDs. How the maternal as well as the fetal immune system affect human neurodevelopment and contribute to NDDs remains unclear. An important reason for this knowledge gap is the fact that the impact of exposure to prenatal risk factors has been challenging to study in the human context. Here, we characterized a model of cerebral organoids (CO) with integrated microglia (COiMg). These organoids express typical microglial markers and respond to inflammatory stimuli. The presence of microglia influences cerebral organoid development, including cell density and neural differentiation, and regulates the expression of several ciliated and mesenchymal cell markers. Moreover, COiMg and organoids without microglia show similar but also distinct responses to inflammatory stimuli. Additionally, IFN-γ induced significant transcriptional and structural changes in the cerebral organoids, that appear to be regulated by the presence of microglia. Specifically, interferon-gamma (IFN-γ) was found to alter the expression of genes linked to autism. This model provides a valuable tool to study how inflammatory perturbations and microglial presence affect neurodevelopmental processes.

IL-1 Blockade Mitigates Autism and Cerebral Palsy Traits in Offspring In-Utero Exposed to Group B Streptococcus Chorioamnionitis.

Group B Streptococcus (GBS) is one of the most common bacteria responsible for placental and neonatal infection and inflammation resulting in lifelong neurobehavioral impairments. In particular, GBS-induced chorioamnionitis is known in preclinical models to upregulate inflammatory pathways, primarily through the activation of the interleukin-1 (IL-1) pathway, leading to brain injury and subsequent neurodevelopmental issues. Previous studies from our laboratory using Lewis rat pups have shown that male offspring exposed in utero to GBS chorioamnionitis develop brain injuries leading to neurobehavioral impairments such as autistic traits. In the present study, we aimed to explore whether blocking the IL-1 pathway could prevent or mitigate these neurodevelopmental impairments in adulthood. Using our established preclinical model, we administered IL-1 receptor antagonist (IL-1Ra) to dams with GBS-induced chorioamnionitis. Here, we show that IL-1Ra administration to dams reversed autistic and cerebral palsy traits in male adult offspring exposed in utero to GBS. Hence, IL-1 blockade could serve as a therapeutic intervention against pathogen-induced neurodevelopmental disorders. This research supports the need for future human randomized controlled trials to assess IL-1 blockade administered during pregnancy or in newborns as a strategy to reduce the long-term neurobehavioral consequences of prenatal infections, such as autism, cerebral palsy, learning disabilities, and other neurodevelopmental disorders.

Prenatal and early childhood infections requiring hospitalization and risk of neurodevelopmental disorders in offspring: a population-based birth cohort study in Taiwan.

In utero and early childhood infections have been associated with an increased risk of neurodevelopmental disorders; however, the observed associations may be confounded by familial predispositions. This study examined the neurodevelopmental disorders attributable to maternal infections during pregnancy and early childhood infections during the first year of life, including autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), tic disorders, and mental retardation (MR). We performed population and sibling comparison analyses to account for unmeasured familial confounding factors. We conducted a register-based cohort study with 2,885,662 individuals (comprising 1,864,660 full siblings) born in Taiwan between 2001 and 2018 and followed up until 2021. We employed Cox regression analysis to assess the association between in utero and early childhood infections requiring hospitalization and the subsequent risk of neurodevelopmental disorders. In the population analyses, an offspring exposed to maternal infection had an increased risk for ASD (hazard ratio (HR) = 1.19, 95% confidence interval (CI): 1.13-1.26), ADHD (HR = 1.14, 95% CI: 1.11-1.18), and MR (HR = 1.21, 95% CI: 1.13-1.30). These associations attenuated toward null in the sibling analyses. Individuals exposed to early childhood infection had an increased risk for ASD (HR = 1.13, 95% CI: 1.10-1.16), ADHD (HR = 1.16, 95% CI: 1.15-1.18), tic disorders (HR = 1.12, 95% CI: 1.09-1.15), and MR (HR = 1.64, 95% CI: 1.60-1.69) in the population analyses; these associations were also significant for ASD (HR = 1.14, 95% CI: 1.07-1.21) and MR (HR = 1.52, 95% CI: 1.44-1.62) in the sibling analyses. The association between maternal infection during pregnancy and offspring neurodevelopmental risk is largely due to familial confounding factors. Conversely, infection in early childhood may be attributable to it being a sensitive period and may play a role in the subsequent risk of ASD and MR.

Contributions of maternal prenatal infection and antibiotic exposure to offspring infection and risk for allergic respiratory conditions through age 5

ObjectivesTo determine if maternal prenatal infection increases risk of offspring postnatal infections through age 5 or diagnosis of respiratory allergy at age 5, independent of prenatal/postnatal antibiotic exposure. To evaluate if frequency of offspring infections mediates an association between prenatal infection and respiratory allergy at age 5. Study designSecondary data analyses were performed from the Child Health and Development Studies (CHDS), a prospective, longitudinal birth cohort that enrolled pregnant women from 1959 to 1966 (N = 19,044 live births). The sample included a subset of mother-offspring dyads (n = 2062) with abstracted medical record data from the prenatal period through age 5 that included information on antibiotic use, infection, and offspring respiratory allergy. ResultsSecond trimester maternal infection was associated with an increased risk of offspring infection (IRR = 1.23; 95% CI = 1.09–1.39; p = 0.001). No significant direct associations were detected between prenatal infection and diagnosis of offspring respiratory allergy. Offspring infection (OR = 1.17; 95% CI = 1.13–1.20; p < 0.001) and antibiotic exposure (OR = 1.28; 95% CI = 1.22–1.33; p < 0.001) were significantly associated with a diagnosis of offspring respiratory allergy. Respiratory allergy diagnosis risk was greater with increasing offspring infection exposure and antibiotics. There was a significant indirect effect of second trimester maternal infection on offspring respiratory allergy, due to infections and not antibiotic use, via offspring infection, indicating a partially mediated effect. ConclusionPrenatal maternal infection may contribute to increase risk for early childhood infections, which in turn, may increase risk for allergic conditions.

Prenatal immune activation in rats and adult exposure to inescapable shocks reveal sex-dependent effects on fear conditioning that might be relevant for schizophrenia

Prenatal infection is considered a relevant factor for neurodevelopmental alterations and psychiatric diseases. Administration of bacterial and viral components during pregnancy in rodents results in maternal immune activation (MIA), leading to schizophrenia-like neurochemical and behavioral changes. Despite some evidence for abnormal fear conditioning in schizophrenia, only a few animal studies have focused on this issue. Therefore, we addressed the impact of the administration of the viral mimetic polyI:C to pregnant Long-Evans rats on the adult offspring response to inescapable shocks (IS) and contextual fear conditioning. In males, polyI:C induced a greater endocrine (plasma ACTH) response to IS and both polyI:C and IS enhanced fear conditioning and generalization to a completely different novel environment (hole-board), with no additive effects, probably due to a ceiling effect. In contrast, a modest impact of polyI:C and a lower impact of IS on contextual fear conditioning and generalization was observed in females. Thus, the present results demonstrate that polyI:C dramatically affected fear response to IS in adult males and support the hypothesis that males are more sensitive than females to this treatment. This model might allow to explore neurobiological mechanisms underlying abnormal responsiveness to fear conditioning and stressors in schizophrenia.

Maternal immune activation exerts long-term effects on activity and sleep in male offspring mice.

Exposure to infectious or non-infectious immune activation during early development is a serious risk factor for long-term behavioural dysfunctions. Mouse models of maternal immune activation (MIA) have increasingly been used to address neuronal and behavioural dysfunctions in response to prenatal infections. One commonly employed MIA model involves administering poly(I:C) (polyriboinosinic-polyribocytdilic acid), a synthetic analogue of double-stranded RNA, during gestation, which robustly induces an acute viral-like inflammatory response. Using electroencephalography (EEG) and infrared (IR) activity recordings, we explored alterations in sleep/wake, circadian and locomotor activity patterns on the adult male offspring of poly(I:C)-treated mothers. Our findings demonstrate that these offspring displayed reduced home cage activity during the (subjective) night under both light/dark or constant darkness conditions. In line with this finding, these mice exhibited an increase in non-rapid eye movement (NREM) sleep duration as well as an increase in sleep spindles density. Following sleep deprivation, poly(I:C)-exposed offspring extended NREM sleep duration and prolonged NREM sleep bouts during the dark phase as compared with non-exposed mice. Additionally, these mice exhibited a significant alteration in NREM sleep EEG spectral powerunder heightened sleep pressure. Together, our study highlights the lasting effects of infection and/or immune activation during pregnancy on circadian activity and sleep/wake patterns in the offspring.

Maternal immune activation accelerates pup reflex development and alters immune proteins in pup stomach contents and brain

Prenatal infection increases the risk for neurodevelopmental disorders including autism spectrum disorder and schizophrenia. To better understand this link, a number of maternal immune activation (MIA) rodent models have been studied. However, the majority of these studies focus on adult behavioural outcomes that mirror adult symptoms related to neurodevelopmental disorders. There is little research reporting the effects of MIA on early postnatal development and even fewer using outbred mouse strains. Here, we use a modified version of the Fox scale to assess the effects of two MIA models, a bacterial model (LPS) and a viral model (PolyIC), on overall mouse pup sensorimotor development in CD-1 mice. Surprisingly, both bacterial and viral MIA models resulted in early reflex development when compared with control pups. To better characterize potential factors related to these changes, we examined indicators of sickness/inflammation in the immune-activated dams and in their pups. Sickness behaviour in the dams resulting from immune activation was assessed using a telemetry implant that allowed for continuous recording of temperature and activity in dams exposed to bacterial or viral immune activation. Although MIA dams showed reduced activity on the day immediately following MIA compared to controls, there was no evidence of fever. All dams showed elevated cytokines/chemokines associated with parturition, but this resolved by day 10 post-parturition and was unaffected by previous immune activation. Although circulating cytokines/chemokines in the dams were similar across MIA treatments, there were differences in the amount of interleukin-12p70 and interleukin-13 present in milk taken from milk bands in MIA pups, and interleukin-4 was overall decreased in LPS pup brain. These findings demonstrate that bacterial and viral models of MIA can result in similar precocious development in mice but differing long-term effects on inflammatory markers in both the milk provided to the pups and in their brains.

From Womb to World: Exploring the Immunological Connections between Mother and Child.

Mother and child are immunologically interconnected by mechanisms that we are only beginning to understand. During pregnancy, multiple molecular and cellular factors of maternal origin are transferred across the placenta and influence the development and function of the fetal and newborn immune system. Altered maternal immune states arising from pregnancy-associated infections or immunizations have the potential to program offspring immune function in ways that may have long-term health consequences. In this study, we review current literature on the impact of prenatal infection and vaccination on the developing immune system, highlight knowledge gaps, and look to the horizon to envision maternal interventions that could benefit both the mother and her child.

Prenatal exposure to common infections and newborn DNA methylation: A prospective, population-based study

BackgroundInfections during pregnancy have been robustly associated with adverse mental and physical health outcomes in offspring, yet the underlying molecular pathways remain largely unknown. Here, we examined whether exposure to common infections in utero associates with DNA methylation (DNAm) patterns at birth and whether this in turn relates to offspring health outcomes in the general population. MethodsUsing data from 2,367 children from the Dutch population-based Generation R Study, we first performed an epigenome-wide association study to identify differentially methylated sites and regions at birth associated with prenatal infection exposure. We also examined the influence of infection timing by using self-reported cumulative infection scores for each trimester. Second, we sought to develop an aggregate methylation profile score (MPS) based on cord blood DNAm as an epigenetic proxy of prenatal infection exposure and tested whether this MPS prospectively associates with offspring health outcomes, including psychiatric symptoms, BMI, and asthma at ages 13–16 years. Third, we investigated whether prenatal infection exposure associates with offspring epigenetic age acceleration – a marker of biological aging. Across all analysis steps, we tested whether our findings replicate in 864 participants from an independent population-based cohort (ALSPAC, UK). ResultsWe observed no differentially methylated sites or regions in cord blood in relation to prenatal infection exposure, after multiple testing correction. 33 DNAm sites showed suggestive associations (p < 5e10 − 5; of which one was also nominally associated in ALSPAC), indicating potential links to genes associated with immune, neurodevelopmental, and cardiovascular pathways. While the MPS of prenatal infections associated with maternal reports of infections in the internal hold out sample in the Generation R Study (R2incremental = 0.049), it did not replicate in ALSPAC (R2incremental = 0.001), and it did not prospectively associate with offspring health outcomes in either cohort. Moreover, we observed no association between prenatal exposure to infections and epigenetic age acceleration across cohorts and clocks. ConclusionIn contrast to prior studies, which reported DNAm differences in offspring exposed to severe infections in utero, we do not find evidence for associations between self-reported clinically evident common infections during pregnancy and DNAm or epigenetic aging in cord blood within the general pediatric population. Future studies are needed to establish whether associations exist but are too subtle to be statistically meaningful with present sample sizes, whether they replicate in a cohort with a more similar infection score as our discovery cohort, whether they occur in different tissues than cord blood, and whether other biological pathways may be more relevant for mediating the effect of prenatal common infection exposure on downstream offspring health outcomes.

Birth Outcomes Related to Prenatal Zika, Dengue, and Other Flavivirus Infections in the Zika en Embarazadas y Niños Prospective Cohort Study in Colombia.

Zika virus (ZIKV) infection in pregnancy is associated with severe abnormalities of the brain and eye and other adverse outcomes. Zika en Embarazadas y Niños was a prospective cohort study conducted in multiple Colombian cities that enrolled pregnant women in their first trimester. Specimens collected from pregnant women (n = 1,519) during February 2017-September 2018 and their infants (n = 1,080) during June 2017-March 2019 were tested for prenatal ZIKV infection by nucleic acid amplification tests or IgM antibody testing. Zika virus infection in pregnancy was present in 3.2% of pregnant women (incidence rate [IR] per 1,000 person-months = 5.9, 95% CI: 4.3-7.8). Presumptive ZIKV infection was present in 0.8% of infants (IR = 1.6, 95% CI: 0.7-2.9). Five percent of infants with prenatal ZIKV exposure or infection presented with Zika-associated abnormalities; 4.7% were small for gestational age. Understanding the risk of ZIKV infection during pregnancy and associated adverse outcomes can help inform counseling efforts.

Prenatal maternal infections and early childhood developmental outcomes: analysis of linked administrative health data for Greater Glasgow &Clyde, Scotland.

Previous research has linked prenatal maternal infections to later childhood developmental outcomes and socioemotional difficulties. However, existing studies have relied on retrospectively self-reported survey data, or data on hospital-recorded infections only, resulting in gaps in data collection. This study used a large linked administrative health dataset, bringing together data from birth records, hospital records, prescriptions and routine child health reviews for 55,856 children born in Greater Glasgow & Clyde, Scotland, 2011-2015, and their mothers. Logistic regression models examined associations between prenatal infections, measured as both hospital-diagnosed prenatal infections and receipt of infection-related prescription(s) during pregnancy, and childhood developmental concern(s) identified by health visitors during 6-8 week or 27-30 month health reviews. Secondary analyses examined whether results varied by (a) specific developmental outcome types (gross-motor-skills, hearing-communication, vision-social-awareness, personal-social, emotional-behavioural-attention and speech-language-communication) and (b) the trimester(s) in which infections occurred. After confounder/covariate adjustment, hospital-diagnosed infections were associated with increased odds of having at least one developmental concern (OR: 1.30; 95% CI: 1.19-1.42). This was broadly consistent across all developmental outcome types and appeared to be specifically linked to infections occurring in pregnancy trimesters 2 (OR: 1.34; 95% CI: 1.07-1.67) and 3 (OR: 1.33; 95% CI: 1.21-1.47), that is the trimesters in which foetal brain myelination occurs. Infection-related prescriptions were not associated with any clear increase in odds of having at least one developmental concern after confounder/covariate adjustment (OR: 1.03; 95% CI: 0.98-1.08), but were associated with slightly increased odds of concerns specifically related to personal-social (OR: 1.12; 95% CI: 1.03-1.22) and emotional-behavioural-attention (OR: 1.15; 95% CI: 1.08-1.22) development. Prenatal infections, particularly those which are hospital-diagnosed (and likely more severe), are associated with early childhood developmental outcomes. Prevention of prenatal infections, and monitoring of support needs of affected children, may improve childhood development, but causality remains to be established.

Investigating low birth weight and preterm birth as potential mediators in the relationship between prenatal infections and early child development: a linked administrative health data analysis

BackgroundPrenatal infections are associated with childhood developmental outcomes such as reduced cognitive abilities, emotional problems and other developmental vulnerabilities. However, there is currently a lack of research examining whether this...

A microglia-containing cerebral organoid model to study early life immune challenges.

Prenatal infections and activation of the maternal immune system have been proposed to contribute to causing neurodevelopmental disorders (NDDs), chronic conditions often linked to brain abnormalities. Microglia are the resident immune cells of the brain and play a key role in neurodevelopment. Disruption of microglial functions can lead to brain abnormalities and increase the risk of developing NDDs. How the maternal as well as the fetal immune system affect human neurodevelopment and contribute to NDDs remains unclear. An important reason for this knowledge gap is the fact that the impact of exposure to prenatal risk factors has been challenging to study in the human context. Here, we characterized a model of cerebral organoids (CO) with integrated microglia (COiMg). These organoids express typical microglial markers and respond to inflammatory stimuli. The presence of microglia influences cerebral organoid development, including cell density and neural differentiation, and regulates the expression of several ciliated mesenchymal cell markers. Moreover, COiMg and organoids without microglia show similar but also distinct responses to inflammatory stimuli. Additionally, IFN-γ induced significant transcriptional and structural changes in the cerebral organoids, that appear to be regulated by the presence of microglia. Specifically, interferon-gamma (IFN-γ) was found to alter the expression of genes linked to autism. This model provides a valuable tool to study how inflammatory perturbations and microglial presence affect neurodevelopmental processes.

Interaction between maternal immune activation and postpartum immune stress in neuropsychiatric phenotypes

Epidemiological evidence has shown that maternal infection is a notable risk factor for developmental psychiatric disorders. Animal models have corroborated this link and demonstrated that maternal immune activation (MIA) induces long-term behavioural deficits and neuroimmunological responses to subsequent immune stress in offspring. However, it is unclear whether MIA offspring are more sensitive or more tolerant to immunological challenges from postnatal infections. Pregnant mice were weighed and injected with a single dose of polyinosinic-polycytidylic acid (poly I:C) or saline at gestational day 9.5, and their male offspring were exposed to poly I:C or saline again during adolescence, adulthood, and middle life. After a two-week recovery from the last exposure to poly I:C, the mice underwent behavioural and neuroendophenotypic evaluations. Finally, the mice were sacrificed, and the expression levels of inflammatory factors and the activation levels of glial cells in the cerebral cortex and hippocampus were evaluated. We found MIA mice have lifelong behavioural deficits and glial activation abnormalities. Postpartum infection exposure at different ages has different consequences. Adolescent and middle life exposure prevents sensorimotor gating deficiency, but adult exposure leads to increased sensitivity to MK-801. Moreover, MIA imposed a lasting impact on the neuroimmune profile, resulting in an enhanced cytokine-associated response and diminished microglial reactivity to postnatal infection. Our results reveal an intricate interplay between prenatal and postpartum infection in neuropsychiatric phenotypes, which identify potential windows where preventive or mitigating measures could be applied.

Examining longitudinal associations between prenatal exposure to infections and child brain morphology

BackgroundMaternal infection during pregnancy has been identified as a prenatal risk factor for the later development of psychopathology in exposed offspring. Neuroimaging data collected during childhood has suggested a link between prenatal exposure to maternal infection and child brain structure and function, potentially offering a neurobiological explanation for the emergence of psychopathology. Additionally, preclinical studies utilizing repeated measures of neuroimaging data suggest that effects of prenatal maternal infection on the offspring’s brain may normalize over time (i.e., catch-up growth). However, it remains unclear whether exposure to prenatal maternal infection in humans is related to long-term differential neurodevelopmental trajectories. Hence, this study aimed to investigate the association between prenatal exposure to infections on child brain development over time using repeated measures MRI data. MethodsWe leveraged data from a population-based cohort, Generation R, in which we examined prospectively assessed self-reported infections at each trimester of pregnancy (N = 2,155). We further used three neuroimaging assessments (at mean ages 8, 10 and 14) to obtain cortical and subcortical measures of the offspring’s brain morphology with MRI. Hereafter, we applied linear mixed-effects models, adjusting for several confounding factors, to estimate the association of prenatal maternal infection with child brain development over time. ResultsWe found that prenatal exposure to infection in the third trimester was associated with a slower decrease in volumes of the pars orbitalis, rostral anterior cingulate and superior frontal gyrus, and a faster increase in the middle temporal gyrus. In the temporal pole we observed a divergent pattern, specifically showing an increase in volume in offspring exposed to more infections compared to a decrease in volume in offspring exposed to fewer infections. We further observed associations in other frontal and temporal lobe structures after exposure to infections in any trimester, though these did not survive multiple testing correction. ConclusionsOur results suggest that prenatal exposure to infections in the third trimester may be associated with slower age-related growth in the regions: pars orbitalis, rostral anterior cingulate and superior frontal gyrus, and faster age-related growth in the middle temporal gyrus across childhood, suggesting a potential sensitive period. Our results might be interpreted as an extension of longitudinal findings from preclinical studies, indicating that children exposed to prenatal infections could exhibit catch-up growth. However, given the lack of differences in brain volume between various infection groups at baseline, there may instead be either a longitudinal deviation or a subtle temporal deviation. Subsequent well-powered studies that extend into the period of full brain development (∼25 years) are needed to confirm whether the observed phenomenon is indeed catch-up growth, a longitudinal deviation, or a subtle temporal deviation.

Age-related changes in behavior profile in male offspring of rats treated with poly I:C-induced maternal immune activation in early gestation.

Autism and schizophrenia are environmental risk factors associated with prenatal viral infection during pregnancy. It is still unclear whether behavior phenotypes change at different developmental stages in offspring following the activation of the maternal immune system. Sprague-Dawley rats received a single caudal vein injection of 10 mg/kg polyinosinic:polycytidylic acid (poly I:C) on gestational day 9 and the offspring were comprehensively tested for behaviors in adolescence and adulthood. Maternal serum levels of interleukin (IL)-6, IL-1β and tumor necrosis factor-α were elevated in poly I:C-treated dams. The offspring of maternal poly I:C-induced rats showed increased anxiety, impaired social approach, and progressive impaired cognitive and sensorimotor gating function. Maternal immune activation led to developmental specificity behavioral impairment in offspring.

Prenatal physical exercise and Zika virus infection have no effect on maternal behavior

Some of the worst effects associated with the Zika virus infection during gestation include microcephaly, and central nervous system damage. Pregnancy-related physical exercise is recognized to improve both the mother's and her unborn child's health. It is widely known that male newborns of late-pregnancy mother infection tend to exhibit more depressive and anxious behaviors as they age. However, nothing is known about how the Zika virus could affect a mother's behavior in the first few days after giving birth. The objective of this study was to evaluate if 4 weeks of moderate-intensity swimming during pregnancy prevents negative outcomes of prenatal Zika infection in the behavior of the dams. Dams were randomly selected and divided into three groups: Mock (n= 8) - untrained group, intraperitoneally injected with saline; Zika (n = 8) - untrained group, intraperitoneally injected with Zika; and Zika/swim (n = 8) - trained group, intraperitoneally injected with Zika. The swimming sessions were initiated before mating, which occurred between the 5th and 7th day of the 1st week of the swimming training, according to the estrous cycle and lasted until the parturition date. Prenatal Zika virus infection did not change maternal body weight or maternal behavior significantly independently of performing or not physical exercise.

Mode of Deliveries and Perinatal Outcomes in Prenatal COVID-19 Infections

Background:: The Royal Thai College of Obstetricians and Gynaecologists (RTCOG) clinical practice guideline (CPG) does not recommend elective Cesarean Section (CS) in case of prenatal maternal COVID-19 infections without obstetric indication. In Thailand, little is known about the mode of deliveries and perinatal outcomes in the mentioned group of patients. Therefore, this study aims to fill the gap in knowledge. Objective:: The objective of this study was to compare the mode of deliveries and perinatal outcomes between pregnant women, who were infected with COVID-19 and those who were without COVID- 19 infection. Methods:: The retrospective cohort study was based on data retrieved between February 1st and March 31st, 2023. The primary data was collected between July 1st, 2021, and October 31st, 2022. Women with COVID-19 infection were matched with the non-COVID-19 group in a 1:1 ratio by date at antenatal care (± 7 days) and their gestational age (± 1 week). Comparison of maternal and perinatal outcomes was made by using chi-squared, Fisher’s exact, relative risk, and t-test as appropriate in STATA software version 10.0. Results:: A total of 252 participants were recruited in this study, with 126 patients in each group. Demographic data between the two groups were comparable except for previous CS. The CS rates in the COVID-19 and non-COVID-19 groups were 46.03% and 30.95%, respectively, with p = 0.009. The significantly increased relative risk of CS in COVID-19 was 1.49 (95%CI, 1.07 to 2.05, p = 0.02). Eight women out of 126 had undergone CS with a “COVID-19 infection” indication (p = 0.007). The length of the maternal hospital stay was comparable. No serious maternal complications were observed. Perinatal outcomes were similar among the two groups, except for neonatal jaundice (p = 0.029), with no reports of COVID-19 infections in delivery-related personnel. Conclusion:: Prenatal COVID-19 infections lead to an increase in CS rate, while perinatal morbidities were comparable in both groups, with COVID-19 and non-COVID-19. The RTCOG’s CPG should be modified.

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

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. 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. 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. 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.

Postnatal Zika virus infection leads to morphological and cellular alterations within the neurogenic niche.

The Zika virus received significant attention in 2016, following a declaration by the World Health Organization of an epidemic in the Americas, in which infections were associated with microcephaly. Indeed, prenatal Zika virus infection is detrimental to fetal neural stem cells and can cause premature cell loss and neurodevelopmental abnormalities in newborn infants, collectively described as congenital Zika syndrome. Contrastingly, much less is known about how neonatal infection affects the development of the newborn nervous system. Here, we investigated the development of the dentate gyrus of wild-type mice following intracranial injection of the virus at birth (postnatal day 0). Through this approach, we found that Zika virus infection affected the development of neurogenic regions within the dentate gyrus and caused reactive gliosis, cell death and a decrease in cell proliferation. Such infection also altered volumetric features of the postnatal dentate gyrus. Thus, we found that Zika virus exposure to newborn mice is detrimental to the subgranular zone of the dentate gyrus. These observations offer insight into the cellular mechanisms that underlie the neurological features of congenital Zika syndrome in children.