Infection as an Exertional Heat Illness Risk Factor: A Prospective Cohort Study.

Neurodevelopmental disorders (NDDs) are a group of conditions that primarily manifest during childhood and are thought to arise from disruptions in early brain development during the prenatal and perinatal periods []. According to the (DSM-5-TR), NDDs include autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), intellectual disability (ID), communication disorders, motor disorders, and specific learning disorders, such as dyslexia []. These disorders frequently co-occur in the same individuals, reflecting overlapping developmental pathways []. In the United States, NDDs are estimated to affect approximately 1 child out of 6, with reports suggesting apparent increases in ASD and ADHD prevalence since the early 2000s, a pattern also noted in other Western countries [–]. However, much of this apparent rise likely reflects changes in diagnostic practices, reporting, and awareness rather than true increases in symptom levels [–]. In addition, some authors have suggested that changes in known risk factors (such as increasing parental age) may also contribute to the observed rise in prevalence []. In France, universal health coverage is provided through national insurance, but access to specialized neurodevelopmental evaluations can vary according to regional resources, socioeconomic status, and education. These differences may affect the likelihood and timing of diagnoses. There is a scarcity of comprehensive epidemiological data within the French context [–], which reflects specific challenges in the recognition and diagnosis of NDDs, often occurring later in France compared to other Western countries []. NDDs result from a combination of risk factors with genetic and/or environmental underpinnings []. Advances in genetic research have highlighted the high degree of shared genetic variants across NDDs, while also identifying disorder-specific risk loci [–]. In contrast, the investigation of shared and specific prenatal and perinatal risk factors remains poorly explored. Among the most consistently identified prenatal and perinatal risk factors, prematurity and being small for gestational age (SGA) have been associated with increased risk for various NDDs [, –]. Neonatal complications, particularly hypoxia, have also been linked to increased risk of NDDs [, ]. In addition, parental age at conception has been associated with increased risk for NDDs, possibly reflecting age-related genetic (for advanced age [–]) or environmental mechanisms (especially for very young age [, ]). For young parental age, associations may also partly reflect genetic confounding, as inherited traits such as impulsivity could lead to increased risky sexual behavior and unplanned pregnancies, contributing to earlier parenthood and higher NDD risk in offspring []. Sex also plays a critical role in the development of NDDs, with male children consistently showing a higher vulnerability to NDDs, with male-to-female ratios typically ranging from 2:1–5:1 depending on the specific disorder and study population [, , , , , ]. Prenatal exposure to alcohol has consistently shown associations with NDDs, with significant exposure leading to Fetal Alcohol Spectrum Disorders (FASD), including the most severe form, Fetal Alcohol Syndrome [, ]. Some epidemiological studies have also linked maternal tobacco consumption during pregnancy with an increased risk of NDDs [, ], but the causal interpretation of these associations remains debated, as residual confounding by familial and behavioral factors may bias effect estimates [, ]. Maternal obesity has also emerged as a potential risk factor for NDDs [, ], possibly reflecting the combined influence of metabolic, inflammatory, and endocrine pathways affecting fetal brain development, although disentangling causal effects from shared familial and socioeconomic factors remains challenging. Socioeconomic factors also significantly influence the risk of NDDs. Children born to parents with lower socioeconomic status are at higher risk for a range of NDDs [, ]. These factors may reflect limited access to healthcare and increased exposure to adverse conditions that can negatively impact early brain development. This overview is not exhaustive, other prenatal and perinatal risk factors, such as maternal medication use during pregnancy, maternal infections, and exposure to environmental toxins, have also been implicated in the etiology of NDDs [–]. Nevertheless, the focus here is on a set of common and consistently reported risk factors associated with multiple NDDs. To date, existing studies have not clearly delineated which of these prenatal and perinatal risk factors are more specifically associated with certain NDDs rather than others. Several limitations contribute to this gap. First, although many studies adjust for a broad range of confounding variables, the selection and measurement of these factors vary widely across populations and study designs, reducing the comparability of findi