Does perinatal exposure to exogenous oxytocin influence child behavioural problems and autistic-like behaviours to 20 years of age?

Intrapartum exposure to synthetic oxytocin, maternal BMI, and neurodevelopmental outcomes in children within the ECHO consortium

BACKGROUND

Synthetic oxytocin (sOT) is frequently administered during parturition. Studies have raised concerns that fetal exposure to sOT may be associated with altered brain development and risk of neurodevelopmental disorders. In a large and diverse sample of children with data about intrapartum sOT exposure and subsequent diagnoses of two prevalent neurodevelopmental disorders, i.e., attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), we tested the following hypotheses: (1) Intrapartum sOT exposure is associated with increased odds of child ADHD or ASD; (2) associations differ across sex; (3) associations between intrapartum sOT exposure and ADHD or ASD are accentuated in offspring of mothers with pre-pregnancy obesity.

METHODS

The study sample comprised 12,503 participants from 44 cohort sites included in the Environmental Influences on Child Health Outcomes (ECHO) consortium. Mixed-effects logistic regression analyses were used to estimate the association between intrapartum sOT exposure and offspring ADHD or ASD (in separate models). Maternal obesity (pre-pregnancy BMI ≥ 30 kg/m2) and child sex were evaluated for effect modification.

RESULTS

Intrapartum sOT exposure was present in 48% of participants. sOT exposure was not associated with increased odds of ASD (adjusted odds ratio [aOR] 0.86; 95% confidence interval [CI], 0.71-1.03) or ADHD (aOR 0.89; 95% CI, 0.76-1.04). Associations did not differ by child sex. Among mothers with pre-pregnancy obesity, sOT exposure was associated with lower odds of offspring ADHD (aOR 0.72; 95% CI, 0.55-0.96). No association was found among mothers without obesity (aOR 0.97; 95% CI, 0.80-1.18).

CONCLUSIONS

In a large, diverse sample, we found no evidence of an association between intrapartum exposure to sOT and odds of ADHD or ASD in either male or female offspring. Contrary to our hypothesis, among mothers with pre-pregnancy obesity, sOT exposure was associated with lower odds of child ADHD diagnosis.

Oxytocin-induced birth causes sex-specific behavioral and brain connectivity changes in developing rat offspring

Despite six decades of the use of exogenous oxytocin for management of labor, little is known about its effects on the developing brain. Motivated by controversial reports suggesting a link between oxytocin use during labor and autism spectrum disorders (ASDs), we employed our recently validated rat model for labor induction with oxytocin to address this important concern. Using a combination of molecular biological, behavioral, and neuroimaging assays, we show that induced birth with oxytocin leads to sex-specific disruption of oxytocinergic signaling in the developing brain, decreased communicative ability of pups, reduced empathy-like behaviors especially in male offspring, and widespread sex-dependent changes in functional cortical connectivity. Contrary to our hypothesis, social behavior, typically impaired in ASDs, was largely preserved. Collectively, our foundational studies provide nuanced insights into the neurodevelopmental impact of birth induction with oxytocin and set the stage for mechanistic investigations in animal models and prospective longitudinal clinical studies.

A nationwide, prospective, cohort study on exogenous oxytocin and delays in early child development: the Japan environment and children's study

Although it remains debatable, exogenous oxytocin, commonly used for labour induction and augmentation, reportedly increases risks of neurodevelopment delay, attention-deficit/hyperactivity disorder, and autism spectrum disorder among children prenatally exposed to exogenous oxytocin. However, only few studies have objectively examined exogenous oxytocin's impact on early childhood development through scoring evaluations. This study investigated the association between exogenous oxytocin exposure and neurodevelopment in 3-year-old children using the Ages and Stages Questionnaires, Third Edition. In this nationwide prospective cohort study, we extracted data from 104,062 foetal records regarding exogenous oxytocin use during labour from the Japan Environment and Children's Study. Participants completed questionnaires throughout the pregnancy and postpartum periods. Outcomes comprised the developmental status less than each cut-off value for the five domains of the Ages and Stages Questionnaire, Third Edition. We conducted multivariable logistic regression analyses on the data of 55,400 children after controlling for confounders. Among the 55,400 included women, 19.0% (n = 10,506) used exogenous oxytocin during labour and 81.0% (n = 44,894) did not. Children exposed to exogenous oxytocin showed no significantly increased risk of developmental delay in any domain (communication: odds ratio [OR] 1.04, 95% confidence interval [CI] 0.92-1.16; gross motor: OR 0.97, 95% CI 0.87-1.08; fine motor: OR 1.00, 95% CI 0.92-1.09; problem-solving: OR 1.02, 95% CI 0.94-1.11; personal-social: OR 0.91, 95% CI 0.80-1.03).   Conclusion: Exogenous oxytocin for labour induction did not adversely affect early childhood development. Further studies accounting for the degree of exogenous oxytocin exposure are required to confirm these results. What is Known: • In developed countries, labour is induced in 20-25% of all pregnancies, for which oxytocin is commonly used. • Studies have associated risks of neurodevelopment delay, attention-deficit/hyperactivity disorder, and autism spectrum disorder with exposure to exogenous oxytocin. What is New: • Evaluation with the Ages and Stages Questionnaire, Third Edition, revealed that exogenous oxytocin use did not adversely affect early childhood development. • This prospective study reinforced the lack of evidence of an association between exogenous oxytocin use and early childhood development after adjustment for confounding and rigorous bias elimination.

Exogenous oxytocin administration during labor and autism spectrum disorder

BACKGROUND

Oxytocin is a neuropeptide hormone that plays a key role in social behavior, stress regulation, and mental health. Synthetic oxytocin administration is a common obstetrical practice, and importantly, previous research has suggested that intrapartum exposure may increase the risk of neurodevelopmental disorders, such as autism spectrum disorder.

OBJECTIVE

This study aimed to examine the association between synthetic oxytocin exposure during labor and autism spectrum disorder diagnosis in the child.

STUDY DESIGN

This population-based retrospective cohort study compared 2 cohorts of children: (1) all children born in British Columbia, Canada between April 1, 2000 and December 31, 2014 (n=414,336 births), and (2) all children delivered at Soroka University Medical Center in Be'er-Sheva, Israel between January 1, 2011 and December 31, 2019 (n=82,892 births). Nine different exposure groups were examined. Cox proportional hazards models were used to estimate crude and adjusted hazard ratios of autism spectrum disorder in both cohorts on the basis of induction and/or augmentation exposure status. To further control for confounding by indication, we conducted sensitivity analyses among a cohort of healthy, uncomplicated deliveries and among a group that was induced only for postdates. In addition, we stratified our analyses by infant sex to assess for potential sex differences.

RESULTS

In the British Columbia cohort, 170,013 of 414,336 deliveries (41.0%) were not induced or augmented, 107,543 (26.0%) were exposed to oxytocin, and 136,780 (33.0%) were induced or augmented but not exposed to oxytocin. In the Israel cohort, 51,790 of 82,892 deliveries (62.5%) were not induced or augmented, 28,852 (34.8%) were exposed to oxytocin, and 2250 (2.7%) were induced or augmented but not exposed to oxytocin. On adjusting for covariates in the main analysis, significant associations were observed in the Israel cohort, including adjusted hazard ratios of 1.51 (95% confidence interval, 1.20-1.90) for oxytocin-augmented births and 2.18 (95% confidence interval, 1.32-3.57) for those induced by means other than oxytocin and not augmented. However, oxytocin induction was not significantly associated with autism spectrum disorder in the Israel cohort. In the Canadian cohort, there were no statistically significant adjusted hazard ratios. Further, no significant sex differences were observed in the fully adjusted models.

CONCLUSION

This study supports that induction of labor through oxytocin administration does not increase the risk of autism spectrum disorder in the child. Our international comparison of 2 countries with differences in clinical practice regarding oxytocin administration for induction and/or augmentation suggests that previous studies reporting a significant association were likely confounded by the underlying indication for the induction.

Neuroanatomical and functional consequences of oxytocin treatment at birth in prairie voles

Birth is a critical period for the developing brain, a time when surging hormone levels help prepare the fetal brain for the tremendous physiological changes it must accomplish upon entry into the 'extrauterine world'. A number of obstetrical conditions warrant manipulations of these hormones at the time of birth, but we know little of their possible consequences on the developing brain. One of the most notable birth signaling hormones is oxytocin, which is administered to roughly 50% of laboring women in the United States prior to / during delivery. Previously, we found evidence for behavioral, epigenetic, and neuroendocrine consequences in adult prairie vole offspring following maternal oxytocin treatment immediately prior to birth. Here, we examined the neurodevelopmental consequences in adult prairie vole offspring following maternal oxytocin treatment prior to birth. Control prairie voles and those exposed to 0.25 mg/kg oxytocin were scanned as adults using anatomical and functional MRI, with neuroanatomy and brain function analyzed as voxel-based morphometry and resting state functional connectivity, respectively. Overall, anatomical differences brought on by oxytocin treatment, while widespread, were generally small, while differences in functional connectivity, particularly among oxytocin-exposed males, were larger. Analyses of functional connectivity based in graph theory revealed that oxytocin-exposed males in particular showed markedly increased connectivity throughout the brain and across several parameters, including closeness and degree. These results are interpreted in the context of the organizational effects of oxytocin exposure in early life and these findings add to a growing literature on how the perinatal brain is sensitive to hormonal manipulations at birth.

Maternal and newborn plasma oxytocin levels in response to maternal synthetic oxytocin administration during labour, birth and postpartum - a systematic review with implications for the function of the oxytocinergic system

BACKGROUND

The reproductive hormone oxytocin facilitates labour, birth and postpartum adaptations for women and newborns. Synthetic oxytocin is commonly given to induce or augment labour and to decrease postpartum bleeding.

AIM

To systematically review studies measuring plasma oxytocin levels in women and newborns following maternal administration of synthetic oxytocin during labour, birth and/or postpartum and to consider possible impacts on endogenous oxytocin and related systems.

METHODS

Systematic searches of PubMed, CINAHL, PsycInfo and Scopus databases followed PRISMA guidelines, including all peer-reviewed studies in languages understood by the authors. Thirty-five publications met inclusion criteria, including 1373 women and 148 newborns. Studies varied substantially in design and methodology, so classical meta-analysis was not possible. Therefore, results were categorized, analysed and summarised in text and tables.

RESULTS

Infusions of synthetic oxytocin increased maternal plasma oxytocin levels dose-dependently; doubling the infusion rate approximately doubled oxytocin levels. Infusions below 10 milliunits per minute (mU/min) did not raise maternal oxytocin above the range observed in physiological labour. At high intrapartum infusion rates (up to 32 mU/min) maternal plasma oxytocin reached 2-3 times physiological levels. Postpartum synthetic oxytocin regimens used comparatively higher doses with shorter duration compared to labour, giving greater but transient maternal oxytocin elevations. Total postpartum dose was comparable to total intrapartum dose following vaginal birth, but post-caesarean dosages were higher. Newborn oxytocin levels were higher in the umbilical artery vs. umbilical vein, and both were higher than maternal plasma levels, implying substantial fetal oxytocin production in labour. Newborn oxytocin levels were not further elevated following maternal intrapartum synthetic oxytocin, suggesting that synthetic oxytocin at clinical doses does not cross from mother to fetus.

CONCLUSIONS

Synthetic oxytocin infusion during labour increased maternal plasma oxytocin levels 2-3-fold at the highest doses and was not associated with neonatal plasma oxytocin elevations. Therefore, direct effects from synthetic oxytocin transfer to maternal brain or fetus are unlikely. However, infusions of synthetic oxytocin in labour change uterine contraction patterns. This may influence uterine blood flow and maternal autonomic nervous system activity, potentially harming the fetus and increasing maternal pain and stress.

Oxytocin Exposure in Labor and its Relationship with Cognitive Impairment and the Genetic Architecture of Autism

Whether there is a relationship between oxytocin (OXT) use in labor and the risk of autism (ASD), and the nature of such relationship, is unclear. By integrating genetic and clinical data in a sample of 176 ASD participants, we tested the hypothesis that OXT is a marker for abnormal prenatal development which leads to impairments in the process of labor. OXT-exposed ASD had more obstetric complications (P = 0.031), earlier onset of symptoms (P = 0.027), poorer cognitive development (P = 0.011), higher mutation burden across neurodevelopment genes (P = 0.020; OR = 5.33) and lower transmission of polygenic risk for ASD (P = 0.0319), than non-exposed ASD. OXT seems to constitute a risk indicator rather than a risk factor for ASD, which is relevant for diagnostic and genetic counselling.

Oxytocin Dynamics in the Body and Brain Regulated by the Receptor for Advanced Glycation End-Products, CD38, CD157, and Nicotinamide Riboside

Investigating the neurocircuit and synaptic sites of action of oxytocin (OT) in the brain is critical to the role of OT in social memory and behavior. To the same degree, it is important to understand how OT is transported to the brain from the peripheral circulation. To date, of these, many studies provide evidence that CD38, CD157, and receptor for advanced glycation end-products (RAGE) act as regulators of OT concentrations in the brain and blood. It has been shown that RAGE facilitates the uptake of OT in mother’s milk from the digestive tract to the cell surface of intestinal epithelial cells to the body fluid and subsequently into circulation in male mice. RAGE has been shown to recruit circulatory OT into the brain from blood at the endothelial cell surface of neurovascular units. Therefore, it can be said that extracellular OT concentrations in the brain (hypothalamus) could be determined by the transport of OT by RAGE from the circulation and release of OT from oxytocinergic neurons by CD38 and CD157 in mice. In addition, it has recently been found that gavage application of a precursor of nicotinamide adenine dinucleotide, nicotinamide riboside, for 12 days can increase brain OT in mice. Here, we review the evaluation of the new concept that RAGE is involved in the regulation of OT dynamics at the interface between the brain, blood, and intestine in the living body, mainly by summarizing our recent results due to the limited number of publications on related topics. And we also review other possible routes of OT recruitment to the brain.

Labor induction with oxytocin in pregnant rats is not associated with oxidative stress in the fetal brain

Despite the widespread use of oxytocin for induction of labor, mechanistic insights into fetal/neonatal wellbeing are lacking because of the absence of an animal model that recapitulates modern obstetric practice. Here, we create and validate a hi-fidelity pregnant rat model that mirrors labor induction with oxytocin in laboring women. The model consists of an implantable preprogrammed microprocessor-controlled infusion pump that delivers a gradually escalating dose of intravenous oxytocin to induce birth at term gestation. We validated the model with molecular biological experiments on the uterine myometrium and telemetry-supported assessment of changes in intrauterine pressure. Finally, we applied this model to test the hypothesis that labor induction with oxytocin would be associated with oxidative stress in the newborn brain. Analysis of biomarkers of oxidative stress and changes in the expression of associated genes were no different between oxytocin-exposed and saline-treated pups, suggesting that oxytocin-induced labor was not associated with oxidative stress in the developing brain. Collectively, we provide a viable and realistic animal model for labor induction and augmentation with oxytocin that would enable new lines of investigation related to the impact of perinatal oxytocin exposure on the mother-infant dyad.

Birth Weight and Childhood Psychopathology in the ABCD Cohort: Association is Strongest for Attention Problems and is Moderated by Sex

Many studies have shown low birth weight is associated with psychopathology later in life, particularly attention-deficit/hyperactivity disorder (ADHD). The association is well-replicated, independent from a variety of potential familial confounds, and follows a dose-response curve (decreasing birth weight linked with increasing odds of disorder). However, the specificity of the association to attention problems is called into question by the extent of comorbidity in ADHD, and recent findings that the association is stronger for autism than ADHD. We test the relative dose-response strength of birth weight on multiple aspects of behavior to explore specificity of the effect to attention problems. We also test recent suggestions that the association between birth weight and attention problems is driven by males. Our sample consisted of 9,076 children aged 9-10 from the United States (Adolescent Brain Cognitive Development study). Outcomes included 9 problem-scales and the total problems scale from the Child Behavior Checklist (CBCL). Attention problems were the most strongly associated with birth weight after controlling for gestational age, potential familial confounds, and multiple testing, supporting the outcome-specificity of this association. Contrary to recent registry-based findings, an association between birth weight and an autism scale was not observed. Sex moderated the effect of birth weight on total problems, attention problems and aggressive behavior such that these inverse associations were strongly driven by males. Our findings have strong implications for sex-specific prediction and etiological models of childhood psychopathology.

Controversies involving the use of SSRIs during pregnancy and the increased risk of having a child with autism spectrum disorders – a case report and literature review

Introduction: There is an ongoing debate as to whether the use of selective serotonin reuptake inhibitors (SSRIs) by pregnant women increases the risk of developing autism spectrum disorders (ASD) in the offspring.

Aim: The aim of the study was to

1) present, based on a case report, the potential factors that may affect the development of ASD in a child,

2) review the literature on the risk of ASD in the case of using SSRIs by a pregnant woman.

Case report: The case report concerns a child of a 33-year-old patient, previously treated for an episode of depression at the age of 23. At the beginning of the 15th week of planned pregnancy, when she was 28 years old, sleep disturbances were observed. Over the next few weeks, she gradually developed a full-blown depressive syndrome which required the use of sertraline. The child was born through a natural delivery, a healthy boy, who was diagnosed with ASD at the age of 2.5 years, which was the trigger for the development of the third episode of depression in the patient.

Conclusions: The results of the research indicate that SSRIs can penetrate the placental barrier, influencing the processes of serotoninergic transmission in the fetus, disrupting neurodevelopmental processes. On the other hand, a higher risk of ASD development in children of depressed mothers who do not use pharmacotherapy was confirmed, compared to the general population and in the case of the occurrence of depressive episodes in mother in the past and in relation to the male fetuses. The greater risk of ASD in children of mothers who take SSRIs may not only be associated with the medication itself but also with the presence of depression and the probable common genetic basis for both disorders. In each case, other risk factors for the development of ASD should also be taken into consideration, e.g. vitamin D3 deficiencies, unsaturated fatty acids, oxytocin levels, the presence of intestinal dysbiosis.

Intrapartum synthetic oxytocin, behavioral and emotional problems in children, and the role of postnatal depressive symptoms, postnatal anxiety and mother-to-infant bonding: A Dutch prospective cohort study

OBJECTIVE

To examine the association between intrapartum synthetic oxytocin and child behavioral and emotional problems and to assess if maternal depressive or anxious symptoms or mother-to-infant bonding play a mediating role in this association.

DESIGN

Prospective cohort study.

SETTING

Population-based Pregnancy Anxiety and Depression Study.

PARTICIPANTS

Pregnant women in their first trimester of pregnancy visiting a total of 109 primary and nine secondary obstetric care centers in the Netherlands between 2010 and 2014 were invited to participate. Follow-up measures used for the present study were collected from May 2010 to January 2019. Women with multiple gestations and with a preterm birth were excluded.

MEASUREMENTS

Intrapartum synthetic oxytocin exposure status was based on medical birth records and was defined as its administration (Yes/No), either for labour induction or augmentation. Child behavioral and emotional problems were measured with the Child Behavior Checklist at up to 60 months postpartum. Maternal depressive symptoms, anxiety and mother-to infant bonding were measured with the Edinburgh Postnatal Depression Scale, State Trait Anxiety Inventory and the Mother-to-Infant Bonding Scale from 6 months postpartum. We used multivariable linear regression models to estimate standardized beta coefficients and unique variance explained.

FINDINGS

1,528 women responded. In total 607 women received intrapartum synthetic oxytocin. Intrapartum synthetic oxytocin administration was not associated with child behavioral and emotional problems, mother-to-infant bonding nor with postnatal anxiety. Intrapartum synthetic oxytocin was however significantly but weakly associated with more postnatal depressive symptoms (β=0.17, 95%CI of 0.03 to 0.30) explaining 0.6% of unique variance. Maternal postnatal depressive symptoms, postnatal anxiety symptoms and suboptimal mother-to-infant bonding were positively associated with child behavioral and emotional problems.

KEY CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

We found no evidence that intrapartum synthetic oxytocin is associated with child behavioral and emotional problems, mother-to-infant bonding, or with postnatal anxiety symptoms. Because there was no association between intrapartum synthetic oxytocin and behavioral and emotional problems in children no mediation analysis was carried out. However, intrapartum synthetic oxytocin was positively but weakly associated with postnatal depressive symptoms. The clinical relevance of this finding is negligible in the general population, but unknown in a population with a high risk of depression.

The Association between Labor Induction and Autism Spectrum Disorders Among Children: A Meta-Analysis

BACKGROUND

It was hypothesized that the oxytocin used during labor could increase the risk of neurodevelopmental disorders, such as ASD.

OBJECTIVE

This meta-analysis pooled all observational studies to obtain the association between labor induction and the risk of ASD among children. We identified all published studies up to August 2020 by search in PubMed, Scopus, Web of Science and gray literature. The pooled odds ratios (OR), relative ratio (RR) and 95% confidence intervals (CI (were calculated as random effect estimates of association among studies.

RESULTS

The pooled estimates of OR and RR reported a significant association between labor induction and ASD among children, respectively (OR = 1.09, 95% CI = 1.04 to 1.15) and (RR = 1.06, 95% CI = 1.02 to 1.09). The subgroup analyses were performed based on the adjusted form and design of studies. OR in crude and adjusted studies were reported to be 1.25(1.01, 1.49) and 1.08(1.02, 1.14), respectively. A significant association was found in adjusted and crude studies. There is no significant association between labor induction and ASD in case-control studies (OR=1.08, 95% CI = 0.99, 1.17).

CONCLUSION

The findings showed that labor induction is associated with an increased risk of ASD among children. Therefore, the findings support that clinical use of oxytocin during labor has a significant negative impact on the long-term mental health of children.

Birth with Synthetic Oxytocin and Risk of Childhood Emotional Disorders: A Danish Population-based Study

BACKGROUND

Concerns have been raised that synthetic oxytocin, a widely used obstetric tool for labor induction and augmentation, may have deleterious effects on the neuropsychological development of children. Few studies have examined the relationship between oxytocin-stimulated labor and emotional disorders.

METHODS

We conducted a nationwide register-based cohort study including 677,629 singletons born in Denmark in the years 2000 to 2012 and followed through 2016 (median age = 10.6 years). Data on oxytocin-stimulation were obtained from the Danish Medical Birth Register. Cases of emotional disorders - anxiety, obsessive-compulsive disorder, mood or traumatic stress disorders or a redeemed prescription for a selective serotonin reuptake inhibitor - were identified using Danish patient and prescription registries.

RESULTS

Oxytocin was used to stimulate 31% of births, and oxytocin-stimulated labor was not associated with childhood emotional disorders (HR = 1.05, 95% CI 0.99, 1.11) after adjustment for maternal history of psychopathology, antidepressants during pregnancy, cohabitation status, highest educational attainment, smoking status during pregnancy, birth year, and indications for labor stimulation. The crude cox model was also small and close to unity (HR = 1.09, 95% CI 1.03, 1.15).

LIMITATIONS

About 50% of our population had reached the age of 10 years, but the outcome included disorders with later average debut ages. Oxytocin dosage levels are not recorded in the registers.

CONCLUSIONS

Our small effect size estimates suggest that perinatal synthetic oxytocin does not contribute to the development of emotional disorders. Current evidence does not warrant revision of guidelines for the use of oxytocin in obstetrics.

Obstetric oxytocin exposure and ADHD and ASD among Danish and Finnish children

Background

Some studies have indicated an increased risk of attention deficit hyperactivity disorder (ADHD) and a small, sex-specific association with autism spectrum disorder (ASD) among children prenatally exposed to obstetric oxytocin. Since oxytocin is widely used in the obstetric ward, these potentially deleterious effects are of concern. Thus, we aimed to examine whether obstetric oxytocin treatment for labour induction or augmentation is associated with ADHD and ASD in offspring born in a two-country design based on data from Denmark and Finland.

Methods

This population-based study used data from national registers in Denmark and Finland. Singletons born in Denmark 2000–10 (n = 577 380) and Finland 1991–2010 (n = 945 543), who survived infancy, were followed until 31 December 2015. ADHD and ASD were defined using diagnostic codes. For ADHD, we also included information on prescribed and redeemed ADHD medication in the definition. Hazards ratios (HRs) with 95% confidence intervals (CI), modelled with age as the underlying time scale, were calculated to estimate the associations.

Results

Oxytocin was used in 31% and 46% of the included deliveries in Denmark and Finland, respectively. In crude analyses, prenatal oxytocin was associated with an approximately 20% increased risk of ADHD and ASD, but confounder adjustment attenuated the association. The adjusted HR was 1.03, 95% CI 1.01–1.05, for ADHD and 1.05, 95% CI 1.02–1.08, for ASD. The results were similar in across country and gender.

Conclusions

We found an association between synthetic oxytocin and ADHD or ASD which is unlikely to reflect a causal association and thus should not support the concern of clinical use. Our results help to allay concerns of obstetric use of oxytocin causing ADHD or ASD.

The effects of oxytocin administration on individuals with ASD: Neuroimaging and behavioral evidence

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by difficulties in social communication and the presence of restricted interests and repetitive behaviors. Although behavioral interventions are numerous, there are no Federal Drug Administration approved pharmacological treatments for the core symptoms of ASD. The neuropeptide oxytocin has been studied in animals for decades, and is involved in pair bonding and social affiliation. Given oxytocin's involvement in social communication in animals, researchers have begun exploring whether oxytocin administration in humans affects social behaviors and attachment. Particular attention has been paid to whether oxytocin has therapeutic benefits for improving social behaviors in individuals with ASD. Research on oxytocin administration in ASD has utilized both behavioral and brain-based outcomes. This chapter reviews the effects of oxytocin administration in ASD, with a focus on functional outcomes from neuroimaging investigations. Evidence of potential therapeutic benefits are reviewed, as well as limitations of extant research. A proposed model for future research into the therapeutic benefits of oxytocin includes combining pharmacological (e.g. oxytocin) and behavioral (e.g. evidence-based behavioral interventions) techniques to improve social communication skills in ASD.

The inflammatory event of birth: How oxytocin signaling may guide the development of the brain and gastrointestinal system

The role of oxytocin (OT) as a neuropeptide that modulates social behavior has been extensively studied and reviewed, but beyond these functions, OT's adaptive functions at birth are quite numerous, as OT coordinates many physiological processes in the mother and fetus to ensure a successful delivery. In this review we explore in detail the potential adaptive roles of oxytocin as an anti-inflammatory, protective molecule at birth for the developing fetal brain and gastrointestinal system based on evidence that birth is a potent inflammatory/immune event. We discuss data with relevance for a number of neurodevelopmental disorders, as well as the emerging role of the gut-brain axis for health and disease. Finally, we discuss the potential relevance of sex differences in OT signaling present at birth in the increased male vulnerability to neurodevelopmental disabilities.

Behavioral and epigenetic consequences of oxytocin treatment at birth

Oxytocin is used in approximately half of all births in the United States during labor induction and/or augmentation. However, the effects of maternal oxytocin administration on offspring development have not been fully characterized. Here, we used the socially monogamous prairie vole to examine the hypothesis that oxytocin exposure at birth can have long-term developmental consequences. Maternally administered oxytocin increased methylation of the oxytocin receptor (Oxtr) in the fetal brain. As adults, oxytocin-exposed voles were more gregarious, with increased alloparental caregiving toward pups and increased close social contact with other adults. Cross-fostering indicated that these effects were the result of direct action on the offspring, rather than indirect effects via postnatal changes in maternal behavior. Male oxytocin-exposed offspring had increased oxytocin receptor density and expression in the brain as adults. These results show that long-term effects of perinatal oxytocin may be mediated by an epigenetic mechanism.

Cumulative Risk of the Oxytocin Receptor Gene Interacts with Prenatal Exposure to Oxytocin Receptor Antagonist to Predict Children's Social Communication Development

Compelling evidence for the far-reaching role of oxytocin (OT) in social cognition and affiliative behaviors set the basis for examining the association between genetic variation in the OT receptor (OXTR) gene and risk for autism spectrum disorder (ASD). In the current study, gene-environment interaction between OXTR and prenatal exposure to either OT or OXTR antagonist (OXTRA) in predicting early social communication development was examined. One hundred and fifty-three children (age: M = 4.32, SD = 1.07) were assigned to four groups based on prenatal history: children whose mothers prenatally received OXTRA and Nifedipine to delay preterm labor (n = 27); children whose mothers received Nifedipine only to delay preterm labor (n = 35); children whose mothers received OT for labor augmentation (n = 56), and a no intervention group (n = 35). Participants completed a developmental assessment of intelligence quotient (IQ), adaptive behavior, and social communication abilities. DNA was extracted via buccal swab. A genetic risk score was calculated based on four OXTR single nucleotide polymorphisms (rs53576, rs237887, rs1042778, and rs2254298) previously reported to be associated with ASD symptomatology. OXTRrisk-allele dosage was associated with more severe autism diagnostics observation schedule (ADOS) scores only in the OXTRA group. In contrast, in the Nifedipine, OT, and no intervention groups, OXTRrisk-allele dosage was not associated with children's ADOS scores. These findings highlight the importance of both genetic and environmental pathways of OT in signaling early social development and raise the need for further research in this field. Autism Res 2019, 12: 1087-1100. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: In the current study, we examined if the association between prenatal exposure to an oxytocin receptor antagonist (OXTRA) and autism spectrum disorder (ASD) related impairments are dependent on an individual's genetic background for the oxytocin receptor gene (OXTR). Children who carried a greater number of risk alleles for the OXTR gene and whose mothers received OXTRA to delay preterm labor showed more ASD-related impairments. The results highlight the importance of both genetic and environmental pathways of oxytocin in shaping early social development.

Assessing risk of neurodevelopmental disorders after birth with oxytocin: a systematic review and meta-analysis

Experts have raised concerns that oxytocin for labor induction and augmentation may have detrimental effects on the neurodevelopment of children. To investigate whether there is the reason for concern, we reviewed and evaluated the available evidence by searching databases with no language or date restrictions up to 9 September 2018. We included English-language studies reporting results on the association between perinatal oxytocin exposure and any cognitive impairment, psychiatric symptoms or disorders in childhood. We assessed the quality of studies using the Newcastle-Ottawa Quality Assessment Scales. Independent risk estimates were pooled using random-effects meta-analyses when at least two independent datasets provided data on the same symptom or disorder. Otherwise, we provided narrative summaries. Two studies examined cognitive impairment, one examined problem behavior, three examined attention-deficit/hyperactivity disorder (ADHD) and seven focused on autism spectrum disorders (ASD). We provided narrative summaries of the studies on cognitive impairment. For ADHD, the pooled risk estimate was 1.17; 95% confidence interval (CI) 0.77-1.78, based on a pooled sample size of 5 47 278 offspring. For ASD, the pooled risk estimate was 1.10; 95% CI 1.04-1.17, based on 8 87 470 offspring. Conclusions that perinatal oxytocin increases the risks of neurodevelopmental problems are premature. Observational studies of low to high quality comprise the evidence-base, and confounding, especially by the genetic or environmental vulnerability, remains an issue. Current evidence is insufficient to justify modifying obstetric guidelines for the use of oxytocin, which state that it should only be used when clinically indicated.