Lower Apgar scores and Caesarean sections are related to attention-deficit/hyperactivity disorder

A Systematic Review and Meta-analysis of Prenatal, Birth, and Postnatal Factors Associated with Attention-Deficit/Hyperactivity Disorder in Children

Previous studies have shown mixed results on the relationship between prenatal, birth, and postnatal ("pregnancy-related") risk factors and attention-deficit/hyperactivity disorder (ADHD). We conducted meta-analyses to identify potentially modifiable pregnancy-related factors associated with ADHD. A comprehensive search of PubMed, Web of Science, and EMBASE in 2014, followed by an updated search in January 2021, identified 69 articles published in English on pregnancy-related risk factors and ADHD for inclusion. Risk factors were included in the meta-analysis if at least three effect sizes with clear pregnancy-related risk factor exposure were identified. Pooled effect sizes were calculated for ADHD overall, ADHD diagnosis, inattention, and hyperactivity/impulsivity. Odds ratios (OR) were calculated for dichotomous measures and correlation coefficients (CC) for continuous measures. Prenatal factors (pre-pregnancy weight, preeclampsia, pregnancy complications, elevated testosterone exposure), and postnatal factors (Apgar score, neonatal illness, no breastfeeding) were positively associated with ADHD overall; the findings for ADHD diagnosis were similar with the exception that there were too few effect sizes available to examine pre-pregnancy weight and lack of breastfeeding. Prenatal testosterone was significantly associated with inattention and hyperactivity/impulsivity. Effect sizes were generally small (range 1.1-1.6 ORs, -0.16-0.11 CCs). Risk factors occurring at the time of birth (perinatal asphyxia, labor complications, mode of delivery) were not significantly associated with ADHD. A better understanding of factors that are consistently associated with ADHD may inform future prevention strategies. The findings reported here suggest that prenatal and postnatal factors may serve as potential targets for preventing or mitigating the symptoms of ADHD.

The Association Between Repeated Measured Febrile Episodes During Early Childhood and Attention Deficit Hyperactivity Disorder: A Large-Scale Population-Based Study

OBJECTIVE

We examined the association between the number, magnitude, and frequency of febrile episodes during the 0 to 4 years of life and subsequent diagnosis of ADHD.

METHODS

This population-based case-control study in an Israeli HMO, Leumit Health Services (LHS), uses a database for all LHS members aged 5 to 18 years between 1/1/2002 and 1/30/2022. The number and magnitude of measured fever episodes during the 0 to 4 years were recorded in individuals with ADHD (N = 18,558) and individually matched non-ADHD controls in a 1:2 ratio (N = 37,116).

RESULTS

A significant, independent association was found between the number and magnitude of febrile episodes during the 0 to 4 years and the probability of a later diagnosis of ADHD. Children who never had a measured temperature >37.5°C had a significantly lower rate of ADHD (OR = 0.834, 95% CI [0.802, 0.866], p < .0001).

CONCLUSIONS

Febrile episodes during 0 to 4 years are associated with a significantly increased rate of a later diagnosis of ADHD in a doseresponse relationship.

Effect of cesarean section on the risk of autism spectrum disorders/attention deficit hyperactivity disorder in offspring: a meta-analysis

PURPOSE

This study was conducted to investigate the relationship between cesarean section (CS) offspring and autism spectrum disorders (ASD)/attention deficit hyperactivity disorder (ADHD).

METHODS

Searching of the databases (PubMed, Web of Science, Embase, and Cochrane Library) for studies on the relationship between mode of delivery and ASD/ADHD until August 2022. The primary outcome was the incidence of ASD/ADHD in the offspring.

RESULTS

This meta-analysis included 35 studies (12 cohort studies and 23 case-control studies). Statistical results showed a higher risk of ASD (odds ratio (OR) = 1.25, P < 0.001) and ADHD (OR = 1.11, P < 0.001) in CS offspring compared to the VD group. Partial subgroup analysis showed no difference in ASD risk between CS and VD offspring in sibling-matched groups (OR = 0.98, P = 0.625). The risk of ASD was higher in females (OR = 1.66, P = 0.003) than in males (OR = 1.17, P = 0.004) in the CS offspring compared with the VD group. There was no difference in the risk of ASD between CS under regional anesthesia group and VD group (OR = 1.07, P = 0.173). However, the risk of ASD was higher in the CS offspring under general anesthesia than in the VD offspring (OR = 1.62, P < 0.001). CS offspring developed autism (OR = 1.38, P = 0.011) and pervasive developmental disorder-not otherwise specified (OR = 1.46, P = 0.004) had a higher risk than VD offspring, but there was no difference in Asperger syndrome (OR = 1.19, P = 0.115). Offspring born via CS had a higher incidence of ADHD in different subgroup analyses (sibling-matched, type of CS, and study design).

CONCLUSIONS

In this meta-analysis, CS was a risk factor for ASD/ADHD in offspring compared with VD.

Burden of mental, behavioral, and neurodevelopmental disorders in the Finnish most preterm children: a national register study

Etiologies and the whole picture in childhood mental, behavioral, and neurodevelopmental disorders related to gestational age are unclear. This study included all Finnish children (N = 341,632) born between January 1, 2001, and December 31, 2006, whose data including their mothers (N = 241,284) were collected from national registers. Children with unclear gestational age (GA) (N = 1245), severe congenital malformations (N = 11,746), and moderate/severe/undefined cognitive impairment (N = 1140), and those who died during the perinatal period (N = 599) were excluded. The main outcome was the prevalence of mental and behavioral disorders (International Classification of Disorders) at 0 - 12 years of age in association with GA, adjusted for gender and prenatal variables. Out of all included (N = 326,902) children 16.6% (N = 54,270) were diagnosed to have any mental health disorder at 0 - 12 years. Adjusted Odd Ratio (OR) were for any disorder in preterm (< 37 weeks) 1.37 [1.28 - 1.46] and 4.03 [3.08 - 5.26] in extreme preterm (≤ 28 weeks) versus term born children, p < 0.05. The lower the GA at birth, the higher the risk for multiple disorders and earlier onset of disorder, p < 0.05. Adjusted ORs were for male/female 1.94 [1.90 - 1.99], maternal mental health disorder (yes/not) 1.99 [1.92 - 2.07], and smoking during pregnancy (yes/not) 1.58 [1.54 - 1.62], and these risks were more common in preterm versus term born children (p < 0.05). Extreme early birth was a strong risk factor per se for any or multiple and early shown mental health disorders. Other risk factors for mental health accumulated to preterm children.

Early brain microstructural development among preterm infants requiring caesarean section versus those delivered vaginally

It is known that the rate of caesarean section (C-section) has been increasing among preterm births. However, the relationship between C-section and long-term neurological outcomes is unclear. In this study, we utilized diffusion tensor imaging (DTI) to characterize the association of delivery method with brain white matter (WM) microstructural integrity in preterm infants. We retrospectively analyzed the DTI scans and health records of preterm infants without neuroimaging abnormality on pre-discharge term-equivalent MRI. We applied both voxel-wise and tract-based analyses to evaluate the association between delivery method and DTI metrics across WM tracts while controlling for numerous covariates. We included 68 preterm infants in this study (23 delivered vaginally, 45 delivered via C-section). Voxel-wise and tract-based analyses revealed significantly lower fractional anisotropy values and significantly higher diffusivity values across major WM tracts in preterm infants delivered via C-section when compared to those delivered vaginally. These results may be partially, but not entirely, mediated by lower birth weight among infants delivered by C-section. Nevertheless, these infants may be at risk for delayed neurodevelopment and could benefit from close neurological follow up for early intervention and mitigation of adverse long-term outcomes.

Cesarean section induced dysbiosis promotes type 2 immunity but not oxazolone-induced dermatitis in mice

Delivery by cesarean section (CS) is associated with an altered gut microbiota (GM) colonization and a higher risk of later chronic inflammatory diseases. Studies investigating the association between CS and atopic dermatitis (AD) are contradictive and often biased by confounding factors. The aim of this study was therefore to provide experimental evidence for the association between CS and AD in a mouse model and clarify the role of the GM changes associated with CS. It was hypothesized that CS-delivered mice, and human CS-GM transplanted mice develop severe dermatitis due to early dysbiosis. BALB/c mice delivered by CS or vaginally (VD) as well as BALB/c mice transplanted with GM from CS or VD human donors were challenged with oxazolone on the ear. The severity of dermatitis was evaluated by ear thickness and clinical and histopathological assessment which were similar between all groups. The immune response was assessed by serum IgE concentration, local cytokine response, and presence of immune cells in the draining lymph node. Both CS-delivered mice and mice inoculated with human CS-GM had a higher IgE concentration. A higher proportion of Th2 cells were also found in the CS-GM inoculated mice, but no differences were seen in the cytokine levels in the affected ears. In support of the experimental findings, a human cohort analysis from where the GM samples were obtained found that delivery mode did not affect the children's risk of developing AD. In conclusion, CS-GM enhanced a Th2 biased immune response, but had no effect on oxazolone-induced dermatitis in mice.

Association between 5-min Apgar score and attention deficit hyperactivity disorder: a Scotland-wide record linkage study of 758,423 school children

BACKGROUND

Attention-deficit hyperactivity disorder (ADHD) affects around 1 in 20 children and is associated with life-long sequelae. Previous studies of the association between Apgar score and ADHD have reported inconsistent findings.

METHODS

Record linkage of maternity, prescribing and school pupil census databases was used to conduct a population e-cohort study of singleton children born in Scotland and attending school in Scotland at any point between 2009 and 2013. Binary logistic regression analysis was used to investigate the association between 5-min Apgar score and treated ADHD adjusting for sociodemographic and maternity confounders.

RESULTS

Of the 758,423 children, 7,292 (0.96%) received ADHD medication. The results suggested a potential dose-response relationship between Apgar score and treated ADHD independent of confounders. Referent to an Apgar score of 10, risk of treated ADHD was higher for scores of 0-3 (adjusted OR 1.76, 95% CI 1.32-2.34), 4-6 (adjusted OR 1.50, 95% CI 1.21-1.86) and even 7-9 (adjusted OR 1.26, 95% CI 1.18-1.36) which are traditionally considered within the normal range.

CONCLUSIONS

In addition to reinforcing the need to maximise Apgar score through good obstetric practice, the findings suggest that Apgar score may be useful in predicting future risk of ADHD and therefore facilitating early diagnosis and treatment.

Early brain microstructural development among preterm infants requiring caesarean section versus those delivered vaginally

It is known that the rate of caesarean section (C-section) has been increasing among preterm births. However, the relationship between C-section and long-term neurological outcomes is unclear. In this study, we utilized diffusion tensor imaging (DTI) to characterize the association of delivery method with brain white matter (WM) microstructural integrity in preterm infants. We retrospectively analyzed the DTI scans and health records of preterm infants without neuroimaging abnormality on pre-discharge term-equivalent MRI. We applied both voxel-wise and tract-based analyses to evaluate the association between delivery method and DTI metrics across WM tracts while controlling for numerous covariates. We included 68 preterm infants in this study (23 delivered vaginally, 45 delivered via C-section). Voxel-wise and tract-based analyses revealed significantly lower fractional anisotropy values and significantly higher diffusivity values across major WM tracts in preterm infants delivered via C-section when compared to those delivered vaginally. These results may be partially, but not entirely, mediated by lower birth weight among infants delivered by C-section. Nevertheless, these infants may be at risk for delayed neurodevelopment and could benefit from close neurological follow up for early intervention and mitigation of adverse long-term outcomes.

Screening of attention deficit hyperactivity disorder among preschool children Gharbia Governorate, Egypt

BACKGROUND

Children who experience mental health issues, such as attention deficit hyperactivity disorder (ADHD), experience significant distress and impairment at home, at school, and in the community. Without adequate care or prevention, this frequently results in adulthood-long distress and impairment at large societal costs. Determining the prevalence of ADHD cases among preschoolers as well as some associated maternal and child risk factors was the aim of this study.

METHODS

An analytical cross-sectional study including 1048 preschool children aged 3-6 years was carried out in Tanta City, Gharbia Governorate. From March to April 2022, a proportionate stratified cluster random sample of them was picked. Data were gathered using a predesigned instrument that included sociodemographic information, family history, maternal and child risk factors, and the Arabic version of the ADHD Rating Scale IV questionnaire.

RESULTS

The prevalence of ADHD among preschoolers was 10.5%. The inattention type was the most common (5.3%), followed by the hyperactivity type (3.4%). There were statistically significant associations regarding positive family history of psychological and neurological symptoms (17.9% positive vs. 9.7% negative), family history of ADHD symptoms (24.5% positive vs. 9.4% negative), active smoking by the mother (21.1% positive vs. 5.3% negative), cesarean section delivery (66.4% positive vs. 53.9% negative), elevated blood pressure during pregnancy (19.1% positive vs. 12.4% negative), and history of taking drugs during pregnancy (43.6% positive vs. 31.7% negative). Significant child risk factors were: exposure to any source containing lead that causes slow poisoning (25.5% positive vs. 12.3% negative), children with cardiac health problems (38.2% positive vs. 16.6% negative), and hours spent by a child in front of the TV or mobile phone (any screens) per day (60.0% of those with positive screening spent more than 2 h/day vs. 45.7% negative).

CONCLUSION

In the Gharbia governorate, 10.5% of preschoolers suffer from ADHD. Significant maternal risk factors for ADHD included a positive family history of psychiatric and neurological symptoms, a family history of ADHD symptoms, active maternal smoking, caesarean section delivery, increased blood pressure during pregnancy, and a history of drug use during pregnancy. Youngsters who had cardiac health issues and who spent more time each day watching TV or using a mobile device (screen use) were at substantial risk.

Impact of Crohn's disease during pregnancy on children with attention deficit hyperactivity disorder: A review

Background

Iron deficiency anemia (IDA) is a common complication of inflammatory bowel disease (IBD) in pregnant women. Although studies have shown that certain maternal autoimmune diseases are associated with attention deficit hyperactivity disorder (ADHD) in children, no studies have found a relationship specifically between and IDA in pregnant women with IBD and ADHD in their children. This review aims identify a relationship between maternal Crohn's disease (CD) with IDA and ADHD in children.

Materials and methods

A review of existing literature was conducted using PubMed to search for articles on pregnant women with CD and IDA and children with ADHD. The studies included nested case-control studies, cohort studies, cross-sectional studies, case-control studies, and literature reviews published from 2012 to 2021.

Results

Among 876 articles generated, 11 studies were chosen for this review. Inclusion criteria consisted of no animal studies, meta-analysis or systematic reviews followed by ADHD related topics and maternal CD and IDA. The findings show that ADHD in progeny may be attributed to maternal CD. Although no studies have shown that IDA in mothers with CD is related to ADHD in offspring, several studies have shown a positive correlation between maternal IDA and ADHD in offspring. Some studies suggest inflammation in IBD during pregnancy can inflame the central nervous system, leading to ADHD in offspring.

Conclusion

IDA is a prevalent complication in CD, and inadequate iron levels are associated with neurodevelopmental problems, such as ADHD. Iron therapy for pregnant mothers diagnosed with CD is suggested to prevent ADHD in offspring.

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Iron deficiency anemia in Crohn's disease during pregnancy and its impact on children with ADHD.

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IDA in CD in pregnant women can potentially be considered as a risk factor in the pathophysiology of ADHD in offspring.

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Iron deficiency is the main cause of anemia in CD.

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Children with ADHD tend to have a higher risk of iron deficiency.

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Iron is involved in the dopaminergic pathway in the central nervous system.

Associations Between Delivery Modes, Birth Outcomes and Offspring Anxiety Disorders in a Population-Based Birth Cohort of Children and Adolescents

OBJECTIVE

Mode of delivery and well-being markers for newborn infants have been associated with later psychiatric problems in children and adolescents. However, only few studies have examined the association between birth outcomes and anxiety disorders and the results have been contradictory.

METHODS

This study was a Finnish population-based register study, which comprised 22,181 children and adolescents with anxiety disorders and 74,726 controls. Three national registers were used to collect the data on exposures, confounders and outcomes. Mode of delivery, the 1-min Apgar score, umbilical artery pH and neonatal monitoring were studied as exposure variables for anxiety disorders and for specific anxiety disorders. Conditional logistic regression was used to examine these associations.

RESULTS

Unplanned and planned cesarean sections increased the odds for anxiety disorders in children and adolescents (adjusted OR 1.08, 95% CI 1.02-1.15 and aOR 1.12, 95% CI 1.05-1.19, respectively). After an additional adjustment for maternal diagnoses, unplanned cesarean sections remained statistically significant (aOR 1.11, 95% CI 1.04-1.18). For specific anxiety disorders, planned cesarean sections and the need for neonatal monitoring increased the odds for specific phobia (aOR 1.21, 95% CI 1.01-1.44 and aOR 1.28, 95% CI 1.07-1.52, respectively).

CONCLUSIONS

Birth by cesarean section increased the odds for later anxiety disorders in children and adolescents and unplanned cesarean sections showed an independent association. Further studies are needed to examine the mechanisms behind these associations.

Is there an association between labor induction and attention-deficit/hyperactivity disorder among children?

BACKGROUND

There is evidence of destructive effects of oxytocin use during labor on neurodevelopment.

PURPOSE

This meta-analysis pooled all observational studies to determine the association between labor induction and the risk of attention-deficit/hyperactivity disorder (ADHD) among children.

METHODS

All observational studies (case-control and cohort) were reviewed until September 2020 after searches of the PubMed, Scopus, and Web of Science databases, the gray literature, and conference proceedings. The pooled odds ratios (ORs), relative ratios (RRs), and 95% confidence intervals (CI (swere calculated as random effect estimates of association among studies.

RESULTS

All observational studies were reviewed, including 4 cohort studies including 2,885,743 participants and 3 casecontrol studies including 51,135 participants (10,961 with ADHD and 40,174 in control groups) with a sample size of 2,936,878 participants. The pooled estimates of OR and RR did not indicate a significant association between labor induction and ADHD among children (OR, 1.13; 95% CI, 0.90-1.35) and (RR, 1.10; 95% CI, 0.96-1.24).

CONCLUSIONS

The findings showed that labor induction is not associated with an increased risk of ADHD among children. However, more studies are needed to investigate the relationship between labor induction and ADHD.

Could Subtle Obstetrical Brachial Plexus Palsy Be Related to Unilateral B Glenoid Osteoarthritis?

Background: Several factors associated with B glenoid are also linked with obstetrical brachial plexus palsy (OBPP). The purpose of this observational study was to determine the incidence of OBPP risk factors in type B patients. Methods: A cohort of 154 patients (68% men, 187 shoulders) aged 63 ± 17 years with type B glenoids completed a questionnaire comprising history of perinatal characteristics related to OBPP. A literature review was performed following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) to estimate the incidence of OBPP risk factors in the general population. Results: Twenty-seven patients (18%) reported one or more perinatal OBPP risk factors, including shoulder dystocia (n = 4, 2.6%), macrosomia >4 kg (n = 5, 3.2%), breech delivery (n = 6, 3.9%), fetal distress (n = 8, 5.2%), maternal diabetes (n = 2, 1.3%), clavicular fracture (n = 2, 1.3%), and forceps delivery (n = 4, 2.6%). The comparison with the recent literature suggested that most perinatal OBPP risk factors were within the normal range, although the incidence of shoulder dystocia, forceps and vaginal breech deliveries exceeded the average rates. Conclusion: Perinatal factors related to OBPP did not occur in a higher frequency in patients with Walch type B OA compared to the general population, although some of them were in the high normal range.

Anesthesia, sex and miscarriage history may influence the association between cesarean delivery and autism spectrum disorder

BACKGROUND

To explore the association between cesarean section (CS) and risk of autism spectrum disorder (ASD), and evaluate the possible factors influencing this association.

METHODS

In total, 950 patients diagnosed with ASD and 764 healthy controls were recruited in this study. Socio-demographic characteristics and prenatal, perinatal, and neonatal characteristics were compared between the two groups. Univariate and multivariable conditional logistic regression analyses were applied to adjust for confounders. Further stratified analyses based on sex and miscarriage history were similarly performed to explore the factors influencing the association between CS and ASD.

RESULTS

CS was evidently associated with an elevated risk of ASD (adjusted odds ratio [aOR] = 1.606, 95% confidence interval (CI) = 1.311-1.969). Unlike regional anesthesia (RA), only CS performed under general anesthesia (GA) consistently elevated the risk of ASD (aOR = 1.887, 95% CI = 1.273-2.798) in females and males in further stratified analysis. The risk of children suffering from ASD following emergency CS was apparently increased in males (aOR = 2.390, 95% CI = 1.392-5.207), whereas a higher risk of ASD was observed among voluntary CS and indicated CS subgroups (aOR = 2.167, 95% CI = 1.094-4.291; aOR = 2.919, 95% CI = 1.789-4.765, respectively) in females. Moreover, the interaction term of CS and past miscarriage history (β = - 0.68, Wald χ2 = 7.5, df = 1, p = 0.006)) was similarly defined as influencing ASD.

CONCLUSIONS

The exposure of children to GA during CS may explain the possible/emerging association between CS and ASD. In addition, sex and miscarriage history could equally be factors influencing the association between CS and ASD.

Associations Between Mode of Birth and Neuropsychological Development in Children Aged 4 Years: Results from a Birth Cohort Study

The aim of this prospective longitudinal study was to examine the association between Cesarean section (CS) and child development and behavior. The sample consisted of 256 children who were born at term without serious perinatal pathologies. Their development and behavior was assessed at the age of four using Ages and Stages Questionnaire (ASQ-3), Children's Behavior Questionnaire and Strength and Difficulties Questionnaire. Multivariate linear regression analyses were conducted to assess the association between CS and child outcomes. CS was associated with better scores in the Problem Solving domain of the ASQ in the whole sample. After stratifying by child sex, the positive association between CS and the Problem Solving domain was significant in boys, while no association was found in girls. Girls were rated less optimally in the Gross Motor domain of the ASQ when born via CS. Mode of birth was not associated with behavioral outcomes.

Maternal serum Vitamin B12 and offspring attention-deficit/hyperactivity disorder (ADHD)

Maternal Vitamin B12 deficiency during pregnancy is associated with offspring neuropsychiatric disorders. Few previous studies examining this association with attention-deficit/hyperactivity disorder (ADHD) report inconsistent findings. The study examines the association between maternal serum Vitamin B12 levels and offsprings' risk of ADHD. This study is based on the Finnish Prenatal Study of ADHD with a nested case-control design. All the singleton children born in Finland between January 1998 and December 1999 and diagnosed with ADHD were included in the study. A total of 1026 cases were matched with an equal number of controls on sex, date of birth and place of birth. Maternal Vitamin B12 levels were assessed using a chemiluminescence microparticle immunoassay and archived from maternal serum banks, collected during the first and early second trimester of pregnancy. Lower maternal Vitamin B12 levels when analyzed as a continuous variable was not associated with offspring ADHD (aOR 0.97, 95% CI 0.79-1.18, p = 0.75). No significant associations were seen in the lowest quintile of Vitamin B12 levels (aOR 0.96, 95% CI 0.73-1.27, p = 0.80). This is the first study examining maternal sera Vitamin B12 levels during early pregnancy and offspring ADHD. The result suggests that Vitamin B12 deficiency during early pregnancy has specificity for some disorders but not with offspring ADHD.

Effects of delivery mode on behavior in mouse offspring

Cesarean section (CS) has been associated with an increased risk of mental disorders in the offspring. This could possibly be explained by an inadequate microbial colonization early in life with a consequential disturbed gut-brain interaction. To investigate the link between delivery mode and behavior and develop a suitable animal model for further research of the gut-brain axis, the aim of this study was to characterize the gut microbiota (GM) together with the behavioral response in various behavioral tests in CS-delivered mice. We hypothesized that mice delivered by CS would present with disturbances in normal physiological behavior possibly due to an inadequate microbial colonization. C57BL/6 mice delivered by CS or vaginal delivery (VD) were cross fostered and, as adults, observed for anxiety-related behavior in the open field test, social deficits in a sociability test and compulsive behavior in the marble burying test. GM was analyzed by 16S rRNA gene amplicon sequencing. The open field test showed that CS-delivered mice had a decreased activity and accelerated defecation compared to VD-delivered mice. In addition, CS-delivered female mice spend less time interacting with cage mates in the sociability test, whereas there was no effect of CS delivery on the average number of marbles buried. In conclusion, CS-delivered mice had a more pronounced anxiety-like behavior and showed less preference for sociability in female offspring.

Prenatal and perinatal risk factors for anxiety disorders among children and adolescents: A systematic review

BACKGROUND

Prenatal and perinatal risk factors for anxiety disorders have rarely been studied, even though they are highly prevalent in children and adolescents. It is important to identify the common risk factors, so that targeted preventive care and early interventions can be provided.

METHODS

A systematic review of the PubMed and PsycInfo databases was conducted to 25 October 2019, according to the Preferred Reporting Items of Systematic Reviews and Meta-analyses guidelines. The protocol was registered on the Prospective Register of Systematic Reviews and the quality assessment was carried out using the Joanna Briggs tools.

RESULTS

The review identified 31 studies from eight countries, including three register studies. Cohort sizes ranged from 69 to 89,404 and diagnoses cases ranged from 4 to 7867. Although various risk factors had been researched, only few of them had been repeatedly studied and the findings were highly inconsistent. The associations between the different risk factors and anxiety disorders seemed weak compared to many other psychiatric disorders, but preterm birth and maternal somatic illnesses may increase the risk for anxiety disorders in offspring.

LIMITATIONS

The studies varied considerably by study design, risk factors and anxiety disorders studied, sample sizes and follow up periods.

CONCLUSIONS

Prenatal and perinatal risk factors for anxiety disorders have been under-researched, compared to other psychiatric disorders. Our systematic review found weak links to prenatal events, but flagged up preterm birth and maternal somatic illnesses as possible avenues for future research.

Meta-analysis found that studies may have overestimated Caesarean section risks for attention-deficit hyperactivity disorder by ignoring confounding factors

AIM

Epidemiological studies on associations between Caesarean sections (C-sections) and attention-deficit hyperactivity disorder (ADHD) have been inconsistent, and we performed a meta-analysis.

METHODS

We systematically searched PubMed and Embase to December 2018 and included nine hospital-based and population registry studies published in 2011-2018. These covered a total study cohort of more than 2.5 million people in eight countries: Australia, Brazil, Denmark, Finland, Germany, Sweden, Turkey and the UK. The analysis provided summary odds ratios (ORs) and 95% confidence intervals (CI) while taking heterogeneity into account.

RESULTS

We found that that C-sections were associated with a small increase in the risk of ADHD (OR 1.14, 95% CI 1.11, 1.17, I² 0%) in offspring. In subgroup analyses, the association remained for both infants born after elective C-sections (OR, 1.15, 1.11, 1.19, I² 0%) and emergency C-sections (OR, 1.13, 1.1, 1.17, I² 45.4%). However, these were only marginally significant when we pooled data from siblings from other pregnancies (OR, 1.06, 1.00-1.13, I² 0%), implying that the association was due to confounding.

CONCLUSION

The statistically significant association between C-sections and ADHD in children can be partially explained by unmeasured confounding. Further research controlling for important confounders is required before firm conclusions can be drawn.

Parental asthma occurrence, exacerbations and risk of attention-deficit/hyperactivity disorder

OBJECTIVE

To investigate whether intrauterine exposure to maternal asthma or asthma exacerbations increases the risk of attention-deficit/hyperactivity disorder (ADHD).

METHODS

Using Danish register data, this cohort study comprised of 961,202 live singletons born in Denmark during 1997-2012. Children were followed to a maximum of 20.0 years from birth until the first of ADHD-diagnosis/prescription, emigration, death, or 31 December 2016. Cox regression models were used to evaluate the association between maternal or paternal asthma, asthma exacerbations and offspring ADHD.

RESULTS

During 11.4 million person-years of follow-up, 27,780 (2.9%) children were identified as having ADHD. ADHD risk was increased among offspring born to asthmatic mothers (hazard ratio (HR) 1.41, 95% CI: 1.36-1.46) or asthmatic fathers (HR 1.13, 95% CI: 1.08-1.18). Antenatal antiasthma medication treatment did not increase offspring ADHD. However, higher risks were observed among offspring of mothers with asthma exacerbations compared with children of asthmatic mothers with no exacerbations: HR 1.12 (95% CI: 1.00-1.25) for pre-pregnancy exacerbations; 1.21 (95% CI: 1.00-1.47) for exacerbations during pregnancy; and 1.25 (95% CI: 1.08-1.44) for exacerbations after delivery.

CONCLUSIONS

These results support theories regarding shared genetic and environmental risk factors having a role in the development of ADHD.

Prefrontal Cortex Dopamine Transporter Gene Network Moderates the Effect of Perinatal Hypoxic-Ischemic Conditions on Cognitive Flexibility and Brain Gray Matter Density in Children

BACKGROUND

Genetic polymorphisms of the dopamine transporter gene (DAT1) and perinatal complications associated with poor oxygenation are risk factors for attentional problems in childhood and may show interactive effects.

METHODS

We created a novel expression-based polygenic risk score (ePRS) reflecting variations in the function of the DAT1 gene network (ePRS-DAT1) in the prefrontal cortex and explored the effects of its interaction with perinatal hypoxic-ischemic-associated conditions on cognitive flexibility and brain gray matter density in healthy children from two birth cohorts-MAVAN from Canada (n = 139 boys and girls) and GUSTO from Singapore (n = 312 boys and girls).

RESULTS

A history of exposure to several perinatal hypoxic-ischemic-associated conditions was associated with impaired cognitive flexibility only in the high-ePRS group, suggesting that variation in the prefrontal cortex expression of genes involved in dopamine reuptake is associated with differences in this behavior. Interestingly, this result was observed in both ethnically distinct birth cohorts. Additionally, parallel independent component analysis (MAVAN cohort, n = 40 children) demonstrated relationships between single nucleotide polymorphism-based ePRS and gray matter density in areas involved in executive (cortical regions) and integrative (bilateral thalamus and putamen) functions, and these relationships differ in children from high and low exposure to hypoxic-ischemic-associated conditions.

CONCLUSIONS

These findings reveal that the impact of conditions associated with hypoxia-ischemia on brain development and executive functions is moderated by genotypes associated with dopamine signaling in the prefrontal cortex. We discuss the potential impact of innovative genomic and environmental measures for the identification of children at high risk for impaired executive functions.

Lifestyle factors, diet and attention-deficit/hyperactivity disorder in Spanish children - an observational study

Background: The aetiology of Attention Deficit Hyperactivity Disorder (ADHD) continues to be debated, although several contributing factors have been acknowledged.Objective: Assess the association between weight, birth attributes, exercise and sleep habits, dietary intake and adherence to a Mediterranean diet, and impulsive behaviour on Spanish ADHD children. Establish whether specific food groups (not just adherence to the Mediterranean diet) associate with impulsive behaviour.Methods: This observational cross-sectional study included 57 ADHD children from Madrid (Spain). Demographic, clinical data, sleep, exercise and technology-use habits were obtained. Anthropometric measurements included height and weight. Adherence to the Mediterranean diet was assessed using the KIDMED test. Barratt Impulsivity Scale version-11c was used to assess impulsivity. Subjects were divided into three groups for analysis, according to their age (6-10 years, children; 11-13 years, pre-adolescents; 14-16 years, adolescents).Results: There were clear associations between those who had higher BIS scores and who slept less at weekends (49.4 ± 10.16 vs. 43.8 ± 12.51), who adhered poorly to the Mediterranean diet (49.9 ± 11.72 vs. 41.6 ± 16.52), who used internet and technological devices for >3 h/day (45.5 ± 13.6 vs. 44.7 ± 12.11), who were born with >2.5 kg (46.1 ± 11.61 vs. 42.9 ± 15.29), who were delivered by caesarean (45.1 ± 12.78 vs. 44.7 ± 12.5) and who were not breastfed (45.0 ± 13.38 vs. 44.8 ± 12.39). Subjects exercising more than 3 days a week also scored slightly higher (45.4±14.02 vs. 44.6±11.85) in the BIS.Conclusion: There is a need to follow up the link between ADHD and sleep onset difficulties, dietary patterns, technological habits, perinatal factors, breastfeeding and birth delivery mode.

Association of Cesarean Delivery With Risk of Neurodevelopmental and Psychiatric Disorders in the Offspring: A Systematic Review and Meta-analysis

Importance

Birth by cesarean delivery is increasing globally, particularly cesarean deliveries without medical indication. Children born via cesarean delivery may have an increased risk of negative health outcomes, but the evidence for psychiatric disorders is incomplete.

Objective

To evaluate the association between cesarean delivery and risk of neurodevelopmental and psychiatric disorders in the offspring.

Data Sources

Ovid MEDLINE, Embase, Web of Science, and PsycINFO were searched from inception to December 19, 2018. Search terms included all main mental disorders in the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition).

Study Selection

Two researchers independently selected observational studies that examined the association between cesarean delivery and neurodevelopmental and psychiatric disorders in the offspring.

Data Extraction and Synthesis

Two researchers independently extracted data according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guidelines and assessed study quality using the Newcastle-Ottawa Scale. Random-effects meta-analyses were used to pool odds ratios (ORs) with 95% CIs for each outcome. Sensitivity and influence analyses tested the robustness of the results.

Main Outcomes and Measures

The ORs for the offspring with any neurodevelopmental or psychiatric disorder who were born via cesarean delivery compared with those were born via vaginal delivery.

Results

A total of 6953 articles were identified, of which 61 studies comprising 67 independent samples were included, totaling 20 607 935 deliveries. Compared with offspring born by vaginal delivery, offspring born via cesarean delivery had increased odds of autism spectrum disorders (OR, 1.33; 95% CI, 1.25-1.41; I2 = 69.5%) and attention-deficit/hyperactivity disorder (OR, 1.17; 95% CI, 1.07-1.26; I2 = 79.2%). Estimates were less precise for intellectual disabilities (OR, 1.83; 95% CI, 0.90-3.70; I2 = 88.2%), obsessive-compulsive disorder (OR, 1.49; 95% CI, 0.87-2.56; I2 = 67.3%), tic disorders (OR, 1.31; 95% CI, 0.98-1.76; I2 = 75.6%), and eating disorders (OR, 1.18; 95% CI, 0.96-1.47; I2 = 92.7%). No significant associations were found with depression/affective psychoses or nonaffective psychoses. Estimates were comparable for emergency and elective cesarean delivery. Study quality was high for 82% of the cohort studies and 50% of the case-control studies.

Conclusions and Relevance

The findings suggest that cesarean delivery births are associated with an increased risk of autism spectrum disorder and attention-deficit/hyperactivity disorder, irrespective of cesarean delivery modality, compared with vaginal delivery. Future studies on the mechanisms behind these associations appear to be warranted.

Parental age and developmental milestones: pilot study indicated a role in understanding ADHD severity in Indian probands

Background

In different ethnic groups, birth related factors have shown significant influence in the etiology of Attention deficit hyperactivity disorder (ADHD). Based on these interesting findings, we aimed to investigate association between different pre- and post natal variables and ADHD associated traits in Indian subjects.

Methods

ADHD Probands recruited based on the DSM-IV, were assessed by the Conner’s Parent Rating Scale for behavioral problem (BPr), inattention (IA), hyperactivity (HA) and ADHD index (AI). Impulsivity (Imp) was assessed by the Tsukuyama scale.

Results

Higher paternal (Std β = 0.23) and lower maternal (Std β = 0.21) age showed significant association with Imp of the probands. Higher paternal age also revealed association with BPr (Std β = 0.18). Age of onset was distinctly associated with AI (Std β < 0.16) while developmental delay was negatively correlated with BPr, Imp, IA and birth weight (r < − 0.13); also confirmed by Posthoc-ANOVA (P < 0.05).

Conclusion

We infer that parental age, developmental delay and birth related variables may have a cumulative effect on ADHD symptom severity.

Electronic supplementary material

The online version of this article (10.1186/s12887-019-1483-x) contains supplementary material, which is available to authorized users.

Moderating effect of mode of delivery on the genetics of intelligence: Explorative genome-wide analyses in ALSPAC

INTRODUCTION

Intelligence is a core construct of individual differences in cognitive abilities and a strong predictor of important life outcomes. Within recent years, rates of cesarean section have substantially increased globally, though little is known about its effect on neurodevelopmental trajectories. Thus, we aimed to investigate the influence of delivery by cesarean section on the genetics of intelligence in children.

METHODS

Participants were recruited through the Avon Longitudinal Study of Parents and Children (ALSPAC). Intelligence was measured by the Wechsler Intelligence Scale for Children (WISC). Genotyping was performed using the Illumina Human Hap 550 quad genome-wide SNP genotyping platform and was followed by imputation using MACH software. Genome-wide interaction analyses were conducted using linear regression.

RESULTS

A total of 2,421 children and 2,141,747 SNPs were subjected to the genome-wide interaction analyses. No variant reached genome-wide significance. The strongest interaction was observed at rs17800861 in the GRIN2A gene (β = -3.43, 95% CI = -4.74 to -2.12, p = 2.98E-07). This variant is predicted to be located within active chromatin compartments in the hippocampus and may influence binding of the NF-kappaB transcription factor.

CONCLUSIONS

Our results may indicate that mode of delivery might have a moderating effect on genetic disposition of intelligence in children. Studies of considerable sizes (>10,000) are likely required to more robustly detect variants governing such interaction. In summary, the presented findings prompt the need for further studies aimed at increasing our understanding of effects various modes of delivery may have on health outcomes in children.