Association Between Assisted Reproductive Technology and Autism Spectrum Disorder

Association Between Maternal Smoking During Pregnancy and Risk of Autism Spectrum Disorder in Offspring: A Systematic Review

Autism Spectrum Disorder (ASD) is a developmental condition that affects how individuals communicate, interact socially, and behave. One of the factor that is gaining attention is maternal smoking during pregnancy. Nicotine and other substances in tobacco smoke can cross the placenta and may interfere with fetal brain development. Despite these concerns, research findings on whether smoking during pregnancy increases the risk of ASD have been mixed. This review examines current evidence on the relationship between maternal smoking during pregnancy and the risk of ASD in offspring. It aims to assess the consistency and strength of reported associations, identify key confounding variables and evaluate the methodological quality of included studies. A structured search was carried out using PRISMA guidelines to identify observational studies published between January 1st 2013 and April 30th 2025. The review focused on studies with cohort, case-control, or cross-sectional designs. Study quality were assessed using tools from the Joanna Briggs Institute (JBI). From an initial pool of 6,915 records, 11 studies met the inclusion criteria. Most were conducted in high-income settings, with sample sizes ranging from fewer than 200 to over two million participants. Five studies reported statistically significant links between maternal smoking and ASD or its subtypes, though the observed effects were small. The remaining six studies, including the only one that used serum cotinine to verify smoking status, did not find a significant association. Differences in results appeared to relate to how smoking exposure and ASD were defined and measured, as well as differences between study populations. There is no clear or consistent evidence that maternal smoking during pregnancy is an independent risk factor for ASD. While some research points to a possible connection, results vary and are often limited by how smoking and ASD were assessed. Further research using more objective exposure data, larger and more diverse populations, and detailed subgroup analyses is needed to clarify whether any meaningful association exists.

Maternal genetic liability to autism spectrum disorders and pregnancy outcomes

Sibling influence on childhood neurodevelopmental disorders: A cohort study in Taiwan.

OBJECTIVE Autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), cerebral palsy (CP), and developmental delay are major childhood neurodevelopmental disorders. Sibling status and birth order may influence neurodevelopmental outcomes, yet population-based evidence remains limited. This study examined their associations with childhood neurodevelopmental disorder risks in a nationwide birth cohort. METHODS We analyzed 2,045,178 live births from Taiwan's Birth Registration Database (2004-2014), linked to National Health Insurance and Death Registry records through 2020. CP, developmental delay, ASD, and ADHD were identified using ICD codes. Children were classified by sibling status and birth order using maternal identifiers. Kaplan-Meier and Cox models estimated adjusted hazard ratios (aHRs), controlling for maternal age, birth period, perinatal factors, socioeconomic status, and urbanization. RESULTS Compared with single children, those with siblings generally showed lower risks of CP and ASD, whereas associations with ADHD and developmental delay varied according to birth order. Later birth order was associated with lower recorded risks of ASD and ADHD. Similar patterns were observed after excluding multiple births and in analyses restricted to diagnoses before 6 years of age. CONCLUSIONS Family structure, including single-child status and birth order, was associated with childhood neurodevelopmental disorder risks. Compared with children who had siblings, single children generally had higher risks across multiple neurodevelopmental outcomes. These findings suggest that family structure may represent an important early-life context for neurodevelopment and may help inform developmental surveillance in societies experiencing declining fertility rates and delayed childbearing.

Prevalence, Distribution, Co-occurring Neurodevelopmental Conditions, and Associated Factors of Autism Among Children in Northern Uganda

Autism is a neurodevelopmental condition characterized by differences in social interaction, communication and behaviour. Despite a global prevalence of one in 127 individuals, autism remains underdiagnosed in low-resource settings. We examined the epidemiology of autism among children aged 2 to 9 years in Northern Uganda. Using multistage sampling, 1,139 children were screened for neurodevelopmental conditions using the validated 23Q screening tool. Children who screened positive underwent clinical assessment, and suspected cases received specialist assessments according to DSM-5-TR criteria. Descriptive statistics and Firth logistic regression were employed for analysis. The mean age was 5.38 years (SD = 2.07), and 51.0% were male. The prevalence of autism was 10.5 per 1,000 children (95% confidence interval [CI] [6.0, 18.5]), of whom 75.0% had co-occurring neurodevelopmental conditions. Autistic children were more likely to have intellectual disability, epilepsy, learning disabilities, global developmental delay, attention-deficit/hyperactivity disorder, dyslexia, cerebral palsy, hearing impairment and speech delay (p < .0045). After adjusting for gender, family history of autism (adjusted odds ratio [aOR] = 6.95, 95% CI [1.60, 30.23]), teenage motherhood (aOR = 8.30, 95% CI [1.30, 53.12]), breech presentation (aOR = 12.23, 95% CI [1.83, 81.64]), and oxygen resuscitation at birth (aOR = 4.56, 95% CI [1.08, 19.33]) were independent predictors of autism. These findings highlight the need to strengthen early identification and targeted services for autistic children in low-resource settings. Lay Abstract Autism affects how people communicate, interact, and process information, and about one in 127 people worldwide are autistic. In low-resource settings, autism is often under-researched and underdiagnosed. We carried out a study in Northern Uganda to estimate how common autism is among children aged 2 to 9 years, to identify co-occurring neurodevelopmental conditions, and to explore factors that may increase likelihood of autism. We enrolled 1,139 children from diverse communities using a multi-step sampling process. After parental consent, one child per household was screened with the 23Q neurodevelopmental screener. Children with possible conditions received further assessment by trained health care workers, and likely cases were confirmed by specialist clinicians using DSM-5-TR diagnostic criteria. Approximately 1 in 95 children were autistic, and none had previously received a diagnosis of autism. The average age of the children diagnosed with autism was about 5 years, and slightly more than half were boys, and most lived in rural areas. Most autistic children (82%) had at least one additional neurodevelopmental condition, such as intellectual disability, learning delays, or epilepsy. Autism was linked to family history, teenage motherhood, and certain birth complications. Improving maternal care, community awareness, and early diagnosis could better support autistic children in Northern Uganda.

Genetic architecture of patients with autism spectrum disorder - data analysis based on the literature review.

Wider access to modern diagnostic methods has increased the number of ASD patients in whom the genetic etiology of the disorder has been uncovered, and knowledge of the genetic background would be applicable in the diagnosis, prevention, prognosis, and individualized treatment.

Birth Weight and Neurodevelopmental Disorders Across Diagnostic Categories: A Registry-Based Case-Control Study in Clinically Ascertained Samples.

Increasing prevalence of neurodevelopmental disorders (NDDs) is a growing public health concern. Identifying early risk markers may facilitate earlier intervention and reduce long-term burden. Although birth weight has been widely studied in relation to NDDs, evidence from clinically ascertained samples with single and overlapping diagnoses remains limited. In this case-control study, we compared birth weight between clinically referred individuals with intellectual disability (ID), autism spectrum disorder (ASD), and attention-deficit/hyperactivity disorder (ADHD) from the Norwegian BUPgen registry (n = 720) and a population-based sample from the Norwegian Mother, Father and Child Cohort Study (MoBa) (n = 98,716). Perinatal data were obtained through linkage to the Medical Birth Registry of Norway. Associations were examined using logistic regression adjusted for gestational age, sex, and parental age. Additional analyses assessed interactions by sex and parental age, and birth weight categories. For each 100 g decrease in birth weight, odds significantly increased for the groups any NDD (one or more NDD diagnoses; OR = 1.04) and multiple diagnoses (two or more co-occurring NDDs; OR = 1.07). In diagnosis specific analyses, odds significantly increased for ID (OR = 1.15) and ASD (OR = 1.03). No interactions were observed. In categorical analyses, low birth weight was associated with higher odds of ID (OR = 8.27, p < 0.001), multiple diagnoses (OR = 4.96, p < 0.001), and any NDD (OR = 2.11, p = 0.002). No associations were observed for high birth weight. These findings support low birth weight as an early marker of neurodevelopmental vulnerability across NDD outcomes.