Swedish cohort study of more than two million parents found cardiovascular risk increased in both mothers and fathers following their child’s diagnosis.
Findings from a large Swedish population-based cohort study suggested that mothers were 27% more likely, and fathers 20% more likely, to develop cardiovascular disease than non-exposed parents.
The findings, based on more than two million parents followed for up to three decades, suggested the long-term psychological and caregiving burden associated with raising children with neurodevelopmental disorders (NDDs) may have measurable downstream cardiovascular consequences.
Researchers found a dose-response relationship in parents of children with NDDs, with the association with CVD increasing with the number of affected children. Researchers also observed that the association was strongest in the first five to 10 years following diagnosis in both mothers and fathers, suggesting a heightened period of cardiovascular vulnerability during the early years of adapting to a child’s NDD.
“If confirmed by future studies, these findings may support the need for enhanced care and early cardiovascular risk monitoring in affected parents,” authors wrote.
From linked national register data from Sweden of all singleton births between 1987 and 2014, researchers identified 187,951 mothers and 143,486 fathers of at least one child with a diagnosed NDD. Parents were followed from the birth of their first child until the first diagnosis of CVD, death, emigration, or until the end of December 2023 – whichever occurred first.
During a median follow-up of 16.7 years, a total of 196,840 mothers (16.7%) and 168,582 fathers (19.1%) developed CVD from the pool of 2,063,076 parents (1,180,457 mothers and 882,619 fathers), including ischemic heart disease, cerebrovascular disease, heart failure, hypertensive disease, atrial fibrillation, cardiomyopathy, and peripheral arterial disease.
Compared with parents without a child diagnosed with an NDD, both maternal and paternal exposure were associated with a significantly increased risk of any CVD (HR 1.27 and 1.20, respectively).
When broken down by the number of children with NDDs per parent, a dose–response gradient was observed. In mothers, the HR for one child was 1.22, while two children and three or more were HR 1.39 and 1.66, respectively.
For fathers of one, two or three or more children with NDDs, HRs were 1.16, 1.33, and 1.50, respectively.
NDDs included intellectual disability (ID), autism spectrum disorder (ASD), and attention-deficit/hyperactivity disorder (ADHD), which authors said collectively affect around one in six children globally.
These associations were broadly consistent across all three categories, authors noted, and there were similar risk estimates whether the child had a single diagnosis or multiple NDDs.
Notably, however, having a child with co-occurring ID and ADHD spiked parental CVD risk (HR 1.43 for mothers and HR 1.25 for fathers) compared to parents with no children with diagnosed NDDs.
Sibling comparison analyses, which included 161,981 families of full sisters (345,766 women) and 146,991 families of full brothers (312,629 men), showed broadly similar HRs. Authors suggested this indicated the association was unlikely to be fully explained by shared familial genetic or environmental confounding.
Findings remained consistent across multiple sensitivity analyses, including adjustment for family history of psychiatric disorders and CVD, maternal BMI, smoking, and adverse pregnancy outcomes, and exclusion of CVD events occurring within six months of exposure.
Parents of children with NDDs were more likely to be younger, have lower income and educational attainment, be unmarried or not in a registered partnership, and have a higher prevalence of psychiatric and familial psychiatric history. Mothers in the exposed group were also more likely to have higher BMI, be smokers and have experienced adverse pregnancy outcomes.
Related
The authors suggested that chronic caregiving stress may play a central role in the observed association. Parents of children with NDDs often face sustained caregiving demands, including coordination with healthcare systems, educational advocacy, and management of behavioural and medical complexity, they explained.
“We speculate that these sex differences [between mothers and fathers] could be attributed to societal and cultural expectations regarding caregiving roles, even in relatively egalitarian contexts such as the Nordic countries,” authors wrote.
“Additionally, gendered norms may influence how stress and distress were perceived, internalized, and expressed.”
They proposed several mechanistic pathways. Chronic psychological stress may contribute to dysregulation of the hypothalamic–pituitary–adrenal axis, increased cortisol secretion, and downstream inflammatory activation. These changes are well established contributors to endothelial dysfunction, atherosclerosis, and cardiometabolic disease.
Acute stress responses may also be relevant. In individuals with pre-existing subclinical atherosclerosis, episodic surges in sympathetic activity, blood pressure, heart rate, and inflammatory mediators could potentially trigger acute cardiovascular events.
Shared genetic liability between psychiatric disorders and cardiovascular disease may also partially contribute to observed associations. Additionally, differences in healthcare utilisation among caregivers – driven by time constraints and competing demands – may lead to reduced engagement with preventive cardiovascular care.
While the absolute risk increase was modest at an individual level, the authors emphasised that the findings were clinically relevant given the prevalence of NDDs and the long duration of exposure to caregiving stress.
