Pre-eclampsia and the risk of autism-spectrum disorder in offspring: meta-analysis

Gut-Amygdala Interactions in Autism Spectrum Disorders: Developmental Roles via regulating Mitochondria, Exosomes, Immunity and microRNAs

BACKGROUND

Autism Spectrum Disorders (ASD) have long been conceived as developmental disorder. A growing body of data highlights a role for alterations in the gut in the pathoetiology and/or pathophysiology of ASD. Recent work shows alterations in the gut microbiome to have a significant impact on amygdala development in infancy, suggesting that the alterations in the gut microbiome may act to modulate not only amygdala development but how the amygdala modulates the development of the frontal cortex and other brain regions.

METHODS

This article reviews wide bodies of data pertaining to the developmental roles of the maternal and foetal gut and immune systems in the regulation of offspring brain development.

RESULTS

A number of processes seem to be important in mediating how genetic, epigenetic and environmental factors interact in early development to regulate such gut-mediated changes in the amygdala, wider brain functioning and inter-area connectivity, including via regulation of microRNA (miR)-451, 14-3-3 proteins, cytochrome P450 (CYP)1B1 and the melatonergic pathways. As well as a decrease in the activity of monoamine oxidase, heightened levels of in miR-451 and CYP1B1, coupled to decreased 14-3-3 act to inhibit the synthesis of N-acetylserotonin and melatonin, contributing to the hyperserotonemia that is often evident in ASD, with consequences for mitochondria functioning and the content of released exosomes. These same factors are likely to play a role in regulating placental changes that underpin the association of ASD with preeclampsia and other perinatal risk factors, including exposure to heavy metals and air pollutants. Such alterations in placental and gut processes act to change the amygdala-driven biological underpinnings of affect-cognitive and affect-sensory interactions in the brain.

CONCLUSION

Such a perspective readily incorporates previously disparate bodies of data in ASD, including the role of the mu-opioid receptor, dopamine signaling and dopamine receptors, as well as the changes occurring to oxytocin and taurine levels. This has a number of treatment implications, the most readily applicable being the utilization of sodium butyrate and melatonin.

Maternal Hypertensive Pregnancy Disorders and Mental Disorders in Children

The associations of maternal hypertensive pregnancy disorders with offspring mental disorders remain unclear. We examined whether maternal hypertensive disorders and maximum blood pressure during pregnancy predict offspring childhood mental disorders, whether the associations are independent of maternal and paternal mental disorders and paternal hypertensive disorders, independent of or additive with maternal early pregnancy overweight/obesity and diabetes mellitus disorders, and mediated or moderated by preterm birth, small-for-gestational-age birth and neonatal intensive care unit admission. Our prospective study comprised 4743 mother-child dyads of Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction study. Women were recruited to the study in early pregnancy at Finnish maternity hospitals. Children were born 2006 to 2010 and followed-up until December 31, 2016, to ages 6.4 to 10.8 years. Hypertensive pregnancy disorders were identified from medical records, Medical Birth Register, and Care Register for Health Care. Systolic and diastolic blood pressure were measured at antenatal clinics and hospital visits. Mental disorder diagnoses were identified from Care Register for Health Care. Maternal gestational and chronic hypertension, preeclampsia and its severity increased offspring hazard of any childhood mental disorder. The associations of preeclampsia (hazard ratio=1.66 [95% CI, 1.14–2.42]) and severe preeclampsia (hazard ratio=2.01 [95% CI, 1.08–3.73]) were independent of all covariates. Maternal hypertensive and diabetes mellitus disorders and overweight/obesity also additively increased offspring hazard of mental disorders. Preterm and small-for-gestational-age births and neonatal intensive care unit admission partially mediated the effects of any and severe preeclampsia on offspring mental disorders. To conclude, maternal hypertensive pregnancy disorders carry adverse consequences for offspring mental health.

Predictive possibility of the transverse cerebellar diameter to abdominal circumference ratio for small-for-gestational-age fetus suspected as a cause of maternal placental syndromes: a retrospective cohort study

Objective: To examine whether fetal transverse cerebellar diameter (TCD) to abdominal circumference (AC) ratio can predict small-for-gestational age suspected as a cause of maternal placental syndromes (SGA-MPS).Methods: We evaluated 473 women who underwent ultrasound examinations at 24-28 weeks of gestation. A receiver operating characteristic curve was used to determine the TCD/AC ratio thresholds to predict SGA-MPS. We used multivariable logistic regression analysis to examine the association.Results: TCD/AC ratio>14.37 was associated with SGA-MPS.Conclusions: Accurate risk stratification using the TCD/AC ratio could assist in managing patients with small-for-gestational-age fetuses at risk of developing MPS-associated adverse outcomes.

Association of Primary Intracerebral Hemorrhage With Pregnancy and the Postpartum Period

IMPORTANCE

Intracerebral hemorrhage (ICH) during pregnancy and the postpartum period results in catastrophic maternal outcomes. There is a paucity of population-based estimates of pregnancy-related ICH risk, including risk during the extended postpartum period.

OBJECTIVE

To evaluate ICH risk during pregnancy and an extended 24-week postpartum period in a population-level cohort and to determine fetal and maternal outcomes as well as demographic and comorbidity factors associated with ICH during pregnancy and post partum.

DESIGN, SETTING, AND PARTICIPANTS

This study used a cohort-crossover design in which patients serve as their own controls when no longer exposed (pregnant or post partum). Administrative data were obtained from all hospital admissions for New York, California, and Florida for a 7- to 10-year period. Participants included all women admitted for labor and delivery who were older than 12 years and did not have a prior diagnosis of ICH. Conditional Poisson regression models were used to evaluate ICH risk, and data were reported as rate ratios and 95% CIs. Data analysis was performed from August 2018 to February 2020.

EXPOSURES

Women were tracked using hospitalization records for the duration of pregnancy (40 weeks), for 24 weeks post partum, and for an additional 64 weeks when no longer exposed.

MAIN OUTCOMES AND MEASURES

Diagnosis of ICH during both 64-week observation periods was determined using validated International Classification of Diseases, Ninth Revision codes.

RESULTS

A total of 3 314 945 pregnant women were included (mean [SD] age, 28.17 [6.47] years; 1 451 780 white [43.79%], 474 808 black [14.32%], 246 789 Asian [7.44%], and 835 917 Hispanic [25.22%]). The risk of ICH was significantly higher during the third trimester (2.9 vs 0.7 cases per 100 000 pregnancies; rate ratio, 4.16; 95% CI, 2.52-6.86) and remained elevated during the first 12 weeks post partum (4.4 vs 0.5 cases per 100 000 pregnancies; rate ratio, 9.15; 95% CI, 5.16-16.23). Advanced maternal age (adjusted odds ratio [OR], 1.08; 95% CI, 1.05-1.10), nonwhite race (adjusted ORs, 2.44 [95% CI, 1.73-3.44] for black patients, 2.12 [95% CI, 1.34-3.35] for Asian patients, and 1.59 [95% CI, 1.12-2.26] for Hispanic patients), hypertension (adjusted OR, 2.02; 95% CI, 1.19-3.42), coagulopathy (adjusted OR, 14.17; 95% CI, 9.17-21.89), preeclampsia or eclampsia (adjusted OR, 9.23; 95% CI, 6.99-12.19), and tobacco use (adjusted OR, 2.83; 95% CI, 1.53-5.23) were independently associated with ICH during pregnancy and the postpartum period. Pregnancy-related ICH was associated with a higher risk of maternal (relative risk difference, 792.6; absolute risk difference, 0.18) and fetal (relative risk difference, 5.3; absolute risk difference, 0.03) death, compared with pregnancies without ICH.

CONCLUSIONS AND RELEVANCE

These findings suggest that the risk of ICH is significantly higher during the third trimester of pregnancy and the first 12 weeks post partum. There are age and race disparities in ICH risk that are associated with devastating maternal and fetal outcomes. These data illustrate the critical need for continuous monitoring and aggressive management of ICH-associated risk factors. These findings suggest that extended postpartum monitoring of high-risk women may be warranted.

Neurodevelopmental Outcomes of Prenatal Preeclampsia Exposure

Preeclampsia is a dangerous hypertensive disorder of pregnancy with known links to negative child health outcomes. Here, we review epidemiological and basic neuroscience work from the past several decades linking prenatal preeclampsia to altered neurodevelopment. This work demonstrates increased rates of neuropsychiatric disorders [e.g., increased autism spectrum disorder, attention deficit hyperactivity disorder (ADHD)] in children of preeclamptic pregnancies, as well as increased rates of cognitive impairments [e.g., decreased intelligence quotient (IQ), academic performance] and neurological disease (e.g., stroke and epilepsy). We also review findings from multiple animal models of preeclampsia. Manipulation of key clinical preeclampsia processes in these models (e.g., placental hypoxia, immune dysfunction, angiogenesis, oxidative stress) causes various disruptions in offspring, including ones in white matter/glia, glucocorticoid receptors, neuroimmune outcomes, cerebrovascular structure, and cognition/behavior. This animal work implicates potentially high-yield targets that may be leveraged in the future for clinical application.

Oligodendrocytes Death Induced Sensorimotor and Cognitive Deficit in N-nitro-L-arginine methyl Rat Model of Pre-eclampsia

Pre-eclampsia (PE) is a pregnancy complicated syndrome that affects multiple organs including the brain that continue post- delivery in both mother and the offspring. We evaluated the expression of oligodendrocytes in the brain of PE rat model through development as well as the cognitive changes and other behavioural modifications that may occur later in the life of offspring of PE-like rat model. Pregnant rats divided into early-onset and late-onset groups were administered with N-nitro- L-arginine methyl (L-NAME) through drinking water at gestational days (GD) 8-17. Rats were allowed free access to water throughout the pregnancy. At GD 19, post-natal day (PND) 1 and 60, rats were sacrificed and brain excised for further analysis. The offspring were subjected to behavioural studies for cognitive and sensorimotor impairments before sacrificed at PND 60. Results showed significant down-regulation in the expression of OLIG2 in PE at GD 19 brain which persists till PND 60. Likewise, there was a significant increase in the latency to locate the platform in Morris water maze, time to traverse the balance beam and reduced hanging time on the wire test between the control and the PE treated. PE could lead to impaired neuronal signalling through demyelination which may contributes significantly to long-term sensorimotor and cognitive deficit.

Overview and Introduction to Autism Spectrum Disorder (ASD)

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder generally manifesting in the first few years of life and tending to persist into adolescence and adulthood. It is characterized by deficits in communication and social interaction and restricted, repetitive patterns of behavior, interests, and activities. It is a disorder with multifactorial etiology. In this chapter, we will focus on the most important and common epidemiological studies, pathogenesis, screening, and diagnostic tools along with an explication of genetic testing in ASD.

Foetal oestrogens and autism

Elevated latent prenatal steroidogenic activity has been found in the amniotic fluid of autistic boys, based on measuring prenatal androgens and other steroid hormones. To date, it is unclear if other prenatal steroids also contribute to autism likelihood. Prenatal oestrogens need to be investigated, as they play a key role in synaptogenesis and corticogenesis during prenatal development, in both males and females. Here we test whether levels of prenatal oestriol, oestradiol, oestrone and oestrone sulphate in amniotic fluid are associated with autism, in the same Danish Historic Birth Cohort, in which prenatal androgens were measured, using univariate logistic regression (n = 98 cases, n = 177 controls). We also make a like-to-like comparison between the prenatal oestrogens and androgens. Oestradiol, oestrone, oestriol and progesterone each related to autism in univariate analyses after correction with false discovery rate. A comparison of standardised odds ratios showed that oestradiol, oestrone and progesterone had the largest effects on autism likelihood. These results for the first time show that prenatal oestrogens contribute to autism likelihood, extending the finding of elevated prenatal steroidogenic activity in autism. This likely affects sexual differentiation, brain development and function.

Preeclampsia exposed offspring have greater body mass index than non-exposed offspring during peripubertal life: A meta-analysis

BACKGROUND

This study evaluates the effect of preeclampsia on body mass index (BMI) of offspring who were exposed to preeclampsia in utero.

METHODS

Data were obtained from studies identified by a literature search in electronic databases. Random-effects metanalyses were conducted to achieve mean difference in BMI, waist circumference, gestation length, and birthweight between preeclampsia exposed (PE) and non-exposed (non-PE) offspring older than 5 years. Metaregression analyses were performed to identify factors affecting offspring BMI.

RESULTS

Sixteen studies (11639 PE offspring; age 15.5 years [14.2, 16.8]; 33.3% [32.6, 33.9] males vs 526,576 non-PE offspring; age 15.7 years [15.0, 16.4]; 42.6% [40.6, 44.5] male) were used. Gestation duration and birthweight of PE fetuses were significantly lesser than those of non-PE fetuses (mean difference (MD) -0.66 weeks [-1.25, -0.07]; p = 0.03 and MD -207.9 [-344.0, -71.8]; p = 0.003) respectively. BMI of PE offspring was significantly higher than non-PE offspring (MD 0.54 kg/m² [0.27, 0.82]; p = 0.0001). Odds of being obese was significantly higher in PE than non-PE offspring (odds ratio 2.12 [1.70, 2.66]; P < 0.00001). Waist circumference was also significantly higher in PE than in non-PE offspring (MD 1.37 cm [0.67, 2.06]; p = 0.0001). Offspring BMI was significantly inversely associated with maternal age in both PE and non-PE groups.

CONCLUSION

Preeclampsia poses risk of higher BMI and waist circumference especially to the offspring of older mothers.

Prenatal exposure to air pollution as a potential risk factor for autism and ADHD

Genetic and environmental factors both contribute to the development of Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD). One suggested environmental risk factor for ASD and ADHD is air pollution, but knowledge of its effects, especially in low-exposure areas, are limited. Here, we investigate risks for ASD and ADHD associated with prenatal exposure to air pollution in an area with air pollution levels generally well below World Health Organization (WHO) air quality guidelines. We used an epidemiological database (MAPSS) consisting of virtually all (99%) children born between 1999 and 2009 (48,571 births) in the study area, in southern Sweden. MAPSS consists of data on modelled nitrogen oxide (NO_x) levels derived from a Gaussian dispersion model; maternal residency during pregnancy; perinatal factors collected from a regional birth registry; and socio-economic factors extracted from Statistics Sweden. All ASD and ADHD diagnoses in our data were undertaken at the Malmö and Lund Departments of Child and Adolescent Psychiatry, using standardized diagnostic instruments. We used logistic regression analyses to obtain estimates of the risk of developing ASD and ADHD associated with different air pollution levels, with adjustments for potential perinatal and socio-economic confounders. In this longitudinal cohort study, we found associations between air pollution exposure during the prenatal period and and the risk of developing ASD. For example, an adjusted Odds Ratio (OR) of 1.40 and its 95% Confidence Interval (CI) (95% CI: 1.02-1.93) were found when comparing the fourth with the first quartile of NO_x exposure. We did not find similar associations on the risk of developing ADHD. This study contributes to the growing evidence of a link between prenatal exposure to air pollution and autism spectrum disorders, suggesting that prenatal exposure even below current WHO air quality guidelines may increase the risk of autism spectrum disorders.

Transtorno do espectro autista e a suplementação por ácido fólico antes e durante a gestação

RESUMO Objetivo Elucidar se a suplementação com ácido fólico pouco antes da concepção e/ou durante a gestação pode estar realmente atrelado ao desenvolvimento do transtorno do espectro autista (TEA). Metódos Foi realizada uma revisão de literatura em base de dados, nos idiomas português e inglês, durante o período de novembro de 2017 até abril de 2018, com ênfase nas publicações mais recentes. Resultados Do total de 174 artigos, 87 compuseram este trabalho. Pesquisas apontam que o aumento dos casos de TEA se deve ao fato de que mais fatores genéticos estejam implicados na etiopatogênese neural. No entanto, a grande maioria dos artigos ressalta com maior precisão que há mais efeitos benéficos do uso de ácido fólico antes da concepção e durante a gestação na prevenção do TEA, assim como de outras anormalidades relacionadas aos defeitos do tubo neural. Conclusão Quando se analisa o risco-benefício da suplementação com ácido fólico nas doses recomendadas, 0,4 a 0,8 mg/dia, conclui-se que os benefícios sobrepujam os possíveis riscos de desenvolver o TEA.

Perinatal Micro-Bleeds and Neuroinflammation in E19 Rat Fetuses Exposed to Utero-Placental Ischemia

Offspring of preeclampsia patients have an increased risk of developing neurological deficits and cognitive impairment. While low placental perfusion, common in preeclampsia and growth restriction, has been linked to neurological deficits, a causative link is not fully established. The goal of this study was to test the hypothesis that placental ischemia induces neuroinflammation and micro-hemorrhages in utero. Timed-pregnant Sprague Dawley rats were weight-matched for sham surgery (abdominal incision only) or induced placental ischemia (surgical reduction of utero-placental perfusion (RUPP)); n = 5/group on gestational day 14. Fetal brains (n = 1–2/dam/endpoint) were collected at embryonic day (E19). Placental ischemia resulted in fewer live fetuses, increased fetal demise, increased hematocrit, and no difference in brain water content in exposed fetuses. Additionally, increased cerebral micro-bleeds (identified with H&E staining), pro-inflammatory cytokines: IL-1β, IL-6, and IL-18, eotaxin (CCL11), LIX (CXCL5), and MIP-2 (CXCL2) were observed in RUPP-exposed fetuses. Microglial density in the sub-ventricular zone decreased in RUPP-exposed fetuses, with no change in cortical thickness. Our findings support the hypothesis that exposure to placental ischemia contributes to microvascular dysfunction (increased micro-bleeds), fetal brain inflammation, and reduced microglial density in proliferative brain areas. Future studies will determine whether in utero abnormalities contribute to long-term behavioral deficits in preeclampsia offspring through impaired neurogenesis regulation.

Environmental risk factors and biomarkers for autism spectrum disorder: an umbrella review of the evidence

BACKGROUND

Numerous studies have identified potential risk factors and biomarkers for autism spectrum disorder. We aimed to study the strength and validity of the suggested environmental risk factors or biomarkers of autism spectrum disorder.

METHODS

We did an umbrella review and systematically appraised the relevant meta-analyses of observational studies. We searched PubMed, Embase, and the Cochrane Database of Systematic Reviews for papers published between database inception and Oct 17, 2018, and screened the reference list of relevant articles. We obtained the summary effect, 95% CI, heterogeneity, and 95% prediction intervals. We examined small study effects and excess significance. We did analyses under credibility ceilings. This review is registered with PROSPERO, number CRD42018091704.

FINDINGS

46 eligible articles yielded data on 67 environmental risk factors (544 212 cases, 81 708 787 individuals) and 52 biomarkers (15 614 cases, 15 433 controls). Evidence of association was convincing for maternal age of 35 years or over (relative risk [RR] 1·31, 95% CI 1·18-1·45), maternal chronic hypertension (odds ratio [OR] 1·48, 1·29-1·70), maternal gestational hypertension (OR 1·37, 1·21-1·54), maternal overweight before or during pregnancy (RR 1·28, 1·19-1·36), pre-eclampsia (RR 1·32, 1·20-1·45), prepregnancy maternal antidepressant use (RR 1·48, 1·29-1·71), and maternal selective serotonin reuptake inhibitor (SSRI) use during pregnancy (OR 1·84, 1·60-2·11). Only two associations, maternal overweight before or during pregnancy and SSRI use during pregnancy, retained their high level of evidence under subset sensitivity analyses. Evidence from biomarkers was scarce, being supported by p values close to the significance threshold and too few cases.

INTERPRETATION

Convincing evidence suggests that maternal factors, such as age and features of metabolic syndrome, are associated with risk of autism spectrum disorder. Although SSRI use during pregnancy was also associated with such risk when exposed and non-exposed groups were compared, this association could be affected by other confounding factors, considering that prepregnancy maternal antidepressant use was also convincingly associated with higher risk of autism spectrum disorder. Findings from previous studies suggest that one possible confounding factor is underlying maternal psychiatric disorders.

FUNDING

None.

Adult Pgf-/- mice behaviour and neuroanatomy are altered by neonatal treatment with recombinant placental growth factor

Offspring of preeclamptic pregnancies have cognitive alterations. Placental growth factor (PGF), is low in preeclampsia; reduced levels may affect brain development. PGF-null mice differ from normal congenic controls in cerebrovasculature, neuroanatomy and behavior. Using brain imaging and behavioral testing, we asked whether developmentally asynchronous (i.e. neonatal) PGF supplementation alters the vascular, neuroanatomic and/or behavioral status of Pgf^−/− mice at adulthood. C57BL/6-Pgf^−/− pups were treated intraperitoneally on postnatal days 1–10 with vehicle or PGF at 10 pg/g, 70 pg/g or 700 pg/g. These mice underwent behavioral testing and perfusion for MRI and analysis of retinal vasculature. A second cohort of vehicle- or PGF-treated mice was perfused for micro-CT imaging. 10 pg/g PGF-treated mice exhibited less locomotor activity and greater anxiety-like behavior relative to vehicle-treated mice. Depressive-like behavior showed a sex-specific, dose-dependent decrease and was lowest in 700 pg/g PGF-treated females relative to vehicle-treated females. Spatial learning did not differ. MRI revealed smaller volume of three structures in the 10 pg/g group, larger volume of seven structures in the 70 pg/g group and smaller volume of one structure in the 700 pg/g group. No cerebral or retinal vascular differences were detected. Overall, neonatal PGF replacement altered behavior and neuroanatomy of adult Pgf^−/− mice.

Hypertensive disorders of pregnancy and the risk of anxiety disorders in adolescence: Findings from the Avon Longitudinal Study of Parents and Children

BACKGROUND

The effect of hypertensive disorders of pregnancy (HDP) on offspring anxiety disorders in adolescence is not yet known. This study aims to examine the association between HDP and offspring anxiety disorders at age 15 years.

METHODS

We used data from 5231 mother-offspring pairs from the United Kingdom based Avon Longitudinal Study of Parents and Children (ALSPAC). Anxiety disorder was diagnosed in the offspring at the age of 15 years using the Development and Well-Being Assessment (DAWBA).

RESULTS

Among those who had anxiety disorders, 16.4% were exposed to HDP. After adjusting for a wide range of known confounders, we found that adolescents of women with HDP had a 2.43 fold (95% CI: 1.41-4.19) increase risk of anxiety disorders compared with adolescents of women without HDP.

CONCLUSIONS

Our study showed that adolescents exposed to HDP had higher risk of anxiety disorders compared with unexposed adolescents and suggests that prevention and treatment of maternal HDP could possibly prevent offspring anxiety in adolescence. Early screening for anxiety disorders in offspring of women with HDP may also be warranted. Further research is needed to explain the pathways by which HDP may increase the risk of offspring psychopathology.

Pre-eclampsia and the risk of attention-deficit/hyperactivity disorder in offspring: Findings from the ALSPAC birth cohort study

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent heterogeneous neurodevelopmental syndrome associated with various environmental factors. This study examined the association between maternal pre-eclampsia and offspring ADHD at 7- and 10-years. The study cohort consisted of more than 7200 children who participated in Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort study. ADHD was diagnosed using parent reported Development and Wellbeing Assessment (DAWBA). Log-binomial regression and Generalized Estimating Equation (GEE) models were used. The GEE analysis showed that pre-eclampsia was associated with increased risk of ADHD in offspring (adjusted risk ratio [RR] = 2.77; 95% confidence interval [CI] = 1.42-5.38). Similarly, the results of multivariable log-binomial regression analysis at each time point showed that pre-eclampsia was associated with an almost threefold increase risk of offspring ADHD. This study suggests that offspring of mothers with pre-eclampsia are at increased risk of ADHD, although residual and unmeasured confounding by environmental and genetic factors warrants further study. If our findings are replicated by others, early screening for ADHD and other developmental delays may be recommended in offspring of women with pre-eclampsia.

The association between preeclampsia and autism spectrum disorders among children: a meta-analysis

Purpose

In this meta-analysis, relevant case-control and cohort studies were pooled to evaluate the association between preeclampsia and the risk of autism spectrum disorders (ASDs) in children.

Methods

A search for relevant studies in major databases, including Web of Science, PubMed, and Scopus, was performed up to May 2018. The odds ratios (ORs) or rate ratios (RRs) with 95% confidence intervals (CIs) were extracted from eligible studies to determine the association among studies.

Results

The pooled estimates of ORs and RRs indicated a significant association between preeclampsia and ASD [(OR, 1.36; 95% CI, 1.12–1.60) and (RR, 1.30; 95% CI, 1.20–1.41)].

Conclusions

Despite existing controversy, our findings indicated that preeclampsia was associated with an increased risk of ASD among children.

Preeclamptic placentae release factors that damage neurons: implications for foetal programming of disease

Prenatal development is a critical period for programming of neurological disease. Preeclampsia, a pregnancy complication involving oxidative stress in the placenta, has been associated with long-term health implications for the child, including an increased risk of developing schizophrenia and autism spectrum disorders in later life. To investigate if molecules released by the placenta may be important mediators in foetal programming of the brain, we analysed if placental tissue delivered from patients with preeclampsia secreted molecules that could affect cortical cells in culture. Application of culture medium conditioned by preeclamptic placentae to mixed cortical cultures caused changes in neurons and astrocytes that were related to key changes observed in brains of patients with schizophrenia and autism, including effects on dendrite lengths, astrocyte number as well as on levels of glutamate and γ-aminobutyric acid receptors. Treatment of the placental explants with an antioxidant prevented neuronal abnormalities. Furthermore, we identified that bidirectional communication between neurons and astrocytes, potentially via glutamate, is required to produce the effects of preeclamptic placenta medium on cortical cells. Analysis of possible signalling molecules in the placenta-conditioned medium showed that the secretion profile of extracellular microRNAs, small post-transcriptional regulators, was altered in preeclampsia and partially rescued by antioxidant treatment of the placental explants. Predicted targets of these differentially abundant microRNAs were linked to neurodevelopment and the placenta. The present study provides further evidence that the diseased placenta may release factors that damage cortical cells and suggests the possibility of targeted antioxidant treatment of the placenta to prevent neurodevelopmental disorders.

Pregnancy outcomes in women with autism: a nationwide population-based cohort study

Background

The consequences of autism in pregnancy outcomes have not been explored before, although it is of crucial importance because of the frequent comorbidities and medication in this group of women.

Objectives

To estimate the risk of adverse pregnancy outcomes in women diagnosed with autism.

Design

Nationwide population-based cohort study.

Setting

Sweden.

Participants

Singleton births identified in the Swedish Medical Birth Registry, 2006–2014. A total of 2,198 births to women diagnosed with autism registered in the Swedish National Patient Registry were compared to 877,742 singleton births to women without such a diagnosis.

Main outcome and measures

Preterm delivery. Secondary measures were cesarean delivery (emergency and elective), Apgar score <7 at 5 minutes, small for gestational age, large for gestational age, stillbirth, gestational diabetes, and preeclampsia. ORs were calculated through logistic regression, adjusted for maternal age at delivery, maternal country of birth, smoking, maternal body mass index, parity, calendar year of birth, and psychotropic and antiepileptic medication during pregnancy.

Results

Women with autism were at increased risk of preterm birth (OR=1.30; 95% CI=1.10–1.54), especially medically indicated preterm birth (OR=1.41; 95% CI=1.08–1.82), but not with spontaneous preterm birth. Maternal autism was also associated with an increased risk of elective cesarean delivery (OR=1.44; 95% CI=1.25–1.66) and preeclampsia (OR=1.34; 95% CI=1.08–1.66), but not with emergency cesarean delivery, low Apgar score (<7), large for gestational age, gestational diabetes, and stillbirth. In women with medication during pregnancy, there was no increased risk of adverse pregnancy outcome except for induction of delivery (OR=1.33; 95% CI=1.14–1.55).

Conclusion and relevance

Maternal autism is associated with preterm birth, likely due to an increased frequency of medically indicated preterm births, but also with other adverse pregnancy outcomes, suggesting a need for extra surveillance during prenatal care.

Effects of placental growth factor deficiency on behavior, neuroanatomy, and cerebrovasculature of mice

Preeclampsia, a hypertensive syndrome occurring in 3-5% of human pregnancies, has lifelong health consequences for fetuses. Cognitive ability throughout life is altered, and adult stroke risk is increased. One potential etiological factor for altered brain development is low concentrations of proangiogenic placental growth factor (PGF). Impaired PGF production may promote an antiangiogenic fetal environment during neural and cerebrovascular development. We previously reported delayed vascularization of the hindbrain, altered retinal vascular organization, and less connectivity in the circle of Willis in Pgf^-/- mice. We hypothesized Pgf^-/- mice would have impaired cognition and altered brain neuroanatomy in addition to compromised cerebrovasculature. Cognitive behavior was assessed in adult Pgf^-/- and Pgf^+/+ mice by four paradigms followed by postmortem high-resolution MRI of neuroanatomy. X-ray microcomputed tomography imaging investigated the three-dimensional cerebrovascular geometry in another cohort. Pgf^-/- mice exhibited poorer spatial memory, less depressive-like behavior, and superior recognition of novel objects. Significantly smaller volumes of 10 structures were detected in the Pgf^-/- compared with Pgf^+/+ brain. Pgf^-/- brain had more total blood vessel segments in the small-diameter range. Lack of PGF altered cognitive functions, brain neuroanatomy, and cerebrovasculature in mice. Pgf^-/- mice may be a preclinical model for the offspring effects of low-PGF preeclampsia gestation.