Norwegian Nationwide Population Study: Single Umbilical Artery Shows Weak Link to ADHD

Counting umbilical cord vessels is standard in prenatal ultrasounds and confirmed at birth. Single umbilical artery (SUA) occurs in about 1 in 200 cases, with roughly 10% associated with anomalies, including central nervous system defects. Isolated SUA (iSUA) means one artery is missing without other structural issues. 

Research on SUA, especially isolated iSUA, and childhood neurodevelopmental disorders (NDD) is limited and inconclusive. iSUA is linked to preterm birth and small-for-gestational age (SGA), both of which are NDD risk factors.  

This Norwegian nationwide population study aimed to assess NDD risk in children with iSUA at birth, the influence of sex, and how preterm birth and SGA mediate this relationship. 

The nation’s universal single-payer health insurance and comprehensive population registries made it possible to analyze all 858,397 single births occurring from 1999 to 2013, with follow-up continuing through 2019. Among these cases, 3,532 involved iSUA. 

After adjusting for confounders such as parental age, education, and maternal health factors, no overall link was found between iSUA and later ADHD diagnosis. However, females with iSUA had about a 40% higher risk of subsequent ADHD compared to those without iSUA, even after adjustment. 

The authors concluded, “The present study indicates that iSUA is weakly associated with ID [intellectual disability] and ADHD, and these associations are influenced by sex. This association is mediated negligibly through preterm birth and SGA. The associations were not clinically significant, and the absence of associations of iSUA with other NDD is reassuring. This finding can be useful in the counseling of expectant parents of fetuses diagnosed with iSUA.” 

 

C. Ebbing, A. Halmoy, E. Jauniaux, A. Einum, S. Rasmussen, and D. Moster, “Association between isolated single umbilical artery and neurodevelopmental disorders: population-based study,” Ultrasound in Obstetrics & Gynecology (2026), https://doi.org/10.1002/uog.70164

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ADHD and Acetaminophen use During Pregnancy

ADHD and Acetaminophen use During Pregnancy

A recent CNN report, http://tinyurl.com/yannlfd6, highlighted a paper published in Pediatrics, which reported that pregnant women who use acetaminophen during pregnancy put their unborn child at two-fold increased risk for attention deficit hyperactivity disorder (ADHD).    In that study, acetaminophen use during pregnancy was common;  nearly half of women surveyed used the painkiller during pregnancy.   Other studies have reported similar associations of acetaminophen, also known as paracetamol with ADHD or with other problems in childhood (e.g., https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5300094/, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4177119/ https://www.ncbi.nlm.nih.gov/pubmed/24566677https://www.ncbi.nlm.nih.gov/pubmed/24163279). Given these prior findings, it seems unlikely that the new report is a chance finding.  But does it make any biological sense?   One answer to that question came from an epigenetic study.  Such studies figure out if assaults from the environment change the genetic code.  One epigenetic study found that prenatal exposure changes the fetal genome via a process called methylation.  Such genomic changes could increase the risk for ADHD (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5540511/). Because all of these studies are observational studies, one cannot assert with certainty that there is a causal link between acetaminophen use during pregnancy. 

The observed association could be due to some unmeasured third factor.  Although the researchers did a respectable job ruling out some third factors, we must acknowledge some uncertainty in the finding.  That said, what should pregnant women do if they need acetaminophen.   I suggest you bring this information to your physician and ask if there is a suitable alternative.

March 16, 2021

How To Best Manage ADHD During Pregnancy to Minimize Risk to Offspring

How can women best manage ADHD during pregnancy to minimize risk to their babies?

Roughly one in thirty adult women have ADHD. Research results indicate that psychostimulants (methylphenidate and amphetamines) offer the most effective course of treatment in most instances. But during pregnancy, such treatment also exposes the fetus to these drugs. Several studies have set out to determine whether such exposure is harmful.

The largest comparison was 5,571 infants exposed to amphetamines and 2,072 exposed to methylphenidate with unexposed infants. It found no increased risks for adverse outcomes due to amphetamine or methylphenidate exposures. Another study studied 3,331 infants exposed to amphetamines, 1,515 exposed to methylphenidate, and 453 to atomoxetine. Comparing these infants to unexposed infants, it found a slightly increased risk of preeclampsia, with an adjusted risk ratio of 1.29 (95% CI 1.11-1.49), but no statistically significant effect for placental abruption, small gestational age, and preterm birth. When assessing the two stimulants, amphetamine, and methylphenidate, together, it found a small increased risk of preterm birth, with an adjusted risk ratio of 1.3 (95% CI 1.10-1.55). There was a statistically significant effect for preeclampsia, placental abruption, or small gestational age. Atomoxetine use was free of any indication of increased risk.

Another study involving 1,591 infants exposed to ADHD medication (mostly methylphenidate) during pregnancy, reported increased risks associated with exposure. The adjusted odds ratio for admission to a neonatal intensive care unit was 1.5 (95% CI 1.3-1.7), and for the central nervous system, disorders were 1.9 (95% CI 1.1-3.1). There was no increased risk for congenital malformations or perinatal death.

Six studies focused on methylphenidate exposure. Two, with a combined total of 402 exposed infants, found no increased risk for malformations. Another, with 208 exposed infants, found a slightly greater risk of cardiovascular malformations, but it was not statistically significant. A fourth, with 186 exposed infants, found no increased risk of malformations but did find a higher rate of miscarriage, with an adjusted hazard ratio of 1.98(95% CI 1.23-3.20). A fifth, with 480 exposed infants, also found a higher rate of miscarriage, with an odds ratio of 2.07 (95% CI 1.51-2.84). But although the sixth, with 382 exposed infants, likewise found an increased risk of miscarriage (adjusted relative risk 1.55 with 95% CI1.03-2.06), it also found an identical risk for women with ADHD who were not on medication during their pregnancies (adjusted relative risk 1.56with 95% CI 1.11-2.20). That finding suggests that all women with ADHD have a higher risk of miscarriage, and that methylphenidate exposure is not the causal factor.

Summing up, while some studies have shown increased adverse effects among infants exposed to maternal ADHD medications, most have not. There are indications that higher rates of miscarriage are associated with maternal ADHD rather than fetal exposure to psychostimulant medications. One study did find a small increased risk of central nervous system disorders and admission to a neonatal intensive care unit. But, again, we do not know whether that was due to exposure to psychostimulant medication or associated with maternal ADHD. If there is a risk, it appears to be a small one.

The question then becomes how to balance that as yet uncertain risk against the disadvantage of discontinuing the effective psychostimulant medication. As the authors of this review conclude. It [ADHD] is associated with significant psychiatric comorbidities for women, including depression, anxiety, substance use disorders, driving safety impairment, and occupational impairment. The gold standard treatment includes behavioral therapy and stimulant medication, namely methylphenidate and amphetamine derivatives. Psychostimulant use during pregnancy continues to increase and has been associated with a small increased relative risk of a range of obstetric concerns. However, the absolute increases in risks are small, and many of the best studies to date are confounded by other medication use and medical comorbidities.

Thus, women with moderate-to-severe ADHD should not necessarily be counseled to suspend their ADHD treatment based on these findings. They advise that when functional impairment from ADHD is moderate to severe, the benefits of stimulant medications may outweigh the small known and unknown risks of medication exposure, and that "If a decision is made to take ADHD medication, women should be informed of the known risks and benefits of the medication use in pregnancy, and take the lowest therapeutic dose possible."

June 18, 2021

Meta-analysis confirms association between overweight mothers and ADHD in offspring

Meta-analysis Confirms Association Between Overweight Mothers and ADHD in Offspring

Noting “the incidence of parental obesity has been rising together with the prevalence of mental illness, suggesting a possible link between the two phenomena,” a Chinese study team performed a systematic search of the peer-reviewed literature on that topic.

Further noting that previous meta-analyses have suggested a link between maternal obesity and increased risk of ADHD in offspring, they set out to also look at paternal obesity.

Only two studies, however, probed the relationship between paternal overweight and obesity and offspring ADHD, making that meta-analysis impractical. A meta-analysis of six studies with a combined total of over a hundred thousand participants found no significant association between overweight or obsess fathers and offspring mental disease of any kind (with all such disorders lumped together). There was no indication of publication bias and little variability (heterogeneity) between studies.

Ten studies with a combined total of over 800,000 participants, however, examined the relationship between overweight and obese mothers and offspring ADHD. Overweight mothers were twenty percent more likely to have offspring with ADHD. Obese mothers were more than fifty percent more likely to have offspring with ADHD. There was absolutely no sign of publication bias in either case. Inter-study heterogeneity was negligible for overweight, and moderate for obesity.

The team concluded, “We found that the most recent evidence indicates the detrimental connections between parental pre-pregnancy overweight/obesity and offspring mental health.” That is perhaps a bit overstated, as the only clear sign was with maternal overweight or obesity.

April 22, 2024

Meta-analysis Finds People with ADHD Twice as Likely to Self-harm

Background: 

Non-suicidal self-injury (NSSI) means intentionally hurting yourself without trying to end your life. Common examples include cutting, scratching, or burning yourself. This behavior is most common in teenagers, affecting 13-20% of adolescents. It’s also called self-harm or deliberate self-injury. 

Young people who struggle with managing emotions, act impulsively, or have mental health conditions like depression are more likely to self-harm. 

Because ADHD involves impulsivity and often occurs alongside emotional difficulties, researchers have suspected a link between ADHD and self-injury. However, previous studies have tended to be small, unrepresentative, and inconsistent, making it hard to draw clear conclusions. 

The Study: 

Researchers combined results from 14 different studies involving nearly 30,000 people to get a clearer picture. They looked at children, teenagers, and adults with ADHD from various settings—including hospitals, community programs, and general population studies. 

To be included, studies had to confirm ADHD diagnosis through professional evaluation or validated testing methods. 

Key findings 

  • About 1 in 4 people with ADHD (27%) have engaged in self-injury. This rate was similar for adults (25%) and teenagers (28%).
  • People with ADHD had more than twice the odds (2.25 times higher) of self-injury compared to people without ADHD 
  • Girls and women with ADHD were at highest risk—they had four times higher rates of self-injury than boys and men with ADHD 

Conclusion: 

The researchers concluded that roughly one in four people with ADHD have engaged in non-suicidal self-harm. The findings suggest that ADHD and self-harm share overlapping vulnerabilities. 

Overall, this meta-analysis strengthens evidence that people with ADHD face a significantly elevated risk of non-suicidal self-injury, likely reflecting overlapping challenges with impulsivity, emotional regulation, and co-occurring mental health conditions. Importantly, this does not mean self-harm is inevitable in ADHD. It does, however, highlight the need for early screening, supportive environments, and targeted mental-health care to help reduce risk and support healthier coping strategies.

March 5, 2026

Meta-analysis Identifies Resilience Factors Associated with Improved Outcomes in Children and Adolescents with ADHD

Background:

While ADHD is generally linked to negative childhood outcomes, individual variability exists. Researchers have found that factors like cognition, emotion, parenting, and social interactions can help some adversity-exposed children develop better than expected. This variability has driven extensive resilience research, which now views resilience not as a single trait, but as a combination of biological, psychological, social, and ecological processes supporting adaptation. 

The Study:

This meta-analysis sought to address several key research gaps. First, while many potential resilience factors have been identified, no previous meta-analysis has quantitatively synthesized evidence focused specifically on children with ADHD. Second, relatively little research has clarified how particular resilience factors relate to specific developmental outcomes. Third, there is currently no integrated conceptual model of resilience processes tailored to children and adolescents with ADHD. 

To keep the analysis focused and clinically relevant, the authors examined psychosocial and ecological resilience factors only. Biological factors (such as genetics or cardiovascular health) and non-modifiable demographic characteristics (such as age and sex) were excluded, as they do not readily inform interventions. The analysis also focused strictly on outcomes for children and adolescents with ADHD, excluding adult outcomes and those reported for parents or teachers. Only studies based on clinical ADHD diagnoses were included. 

In total, 28 studies involving more than 11,600 participants met the inclusion criteria. Fifteen studies were rated as high quality and 13 as fair quality; none were rated low quality. However, the evidence base was relatively thin for many analyses. Of the 50 components examined, only one included five studies, six included four studies, ten included three studies, and most (33) were based on just two studies. While some components involved large samples, most did not, meaning the findings should be viewed as suggestive rather than definitive. 

Results:

Unsurprisingly, academic skills and cognitive functioning – specifically including working memory and intelligence – were strongly associated with better educational outcomes for children and adolescents with ADHD. In contrast, social skills and proactive attitudes or behaviors showed no significant link to educational attainment

Well-being outcomes showed a different pattern. Proactive attitudes and behaviors, cognitive functioning, and parental resources were associated with small-to-moderate improvements in well-being. Emotional regulation and positive parenting or attachment, however, were not significantly related to well-being in this analysis. 

For relationship outcomes, peer relationships – especially close friendships – stood out as particularly important, showing strong associations with better relational functioning. Social skills and positive parenting or attachment were linked to moderate improvements, although positive parenting alone had no significant effect. This suggests that the observed benefit likely stemmed from parental warmth and secure parent–child attachment rather than parenting practices in isolation. Parental resources (such as parental social support) and school-based support (including student–teacher relationships) showed no significant association with relationship outcomes. 

The study also examined behavioral symptoms. Externalizing symptoms refer to outward-directed behaviors that affect others or the environment, such as aggression, defiance, impulsivity, hyperactivity, and rule-breaking. Peer relationships were linked to a modest reduction in these behaviors, while positive relationships with adults were associated with a strong reduction. In contrast, disciplinary parenting – particularly harsh punishment – was strongly associated with increased externalizing symptoms. 

Internalizing symptoms involve inward-directed distress, such as anxiety, depression, withdrawal, excessive worry, and unexplained physical complaints. Here again, positive relationships with adults were important, showing a moderate association with fewer internalizing symptoms. Emotional regulation was also linked to small-to-moderate improvements. 

Conclusion: 

Overall, the findings highlight that resilience factors tend to be closely tied to specific outcomes rather than broadly protective across domains. For example, emotional regulation was associated with lower levels of both internalizing and externalizing symptoms but showed no significant link to well-being, educational achievement, or relationship quality. This suggests that emotional regulation may play a particularly important role in protecting mental health in children with ADHD, rather than driving broader developmental gains – consistent with evidence that emotional dysregulation is a core difficulty in ADHD. 

Similarly, academic skills, social competence, and prosocial behaviors were linked mainly to their most closely related outcomes. Cognitive functioning was associated with both educational and well-being outcomes, but its impact was much stronger in education and more modest for well-being. Together, these context-specific patterns underscore the importance of designing interventions that target particular resilience factors with strategies tailored to specific developmental goals, rather than assuming that any single factor will promote resilience across all areas of life. 

Key takeaway: resilience is individual and resilience isn’t one trait; different types of support help different individuals, in different areas.

Higher Relative Fat Mass (RFM) Associated with Lower ADHD Risk in Boys but Higher ADHD Risk in Girls

Background: 

Traditional measures of obesity, like body mass index (BMI) and waist circumference, have been linked to ADHD risk — but they aren’t great at capturing where fat is actually stored in the body. A newer index called relative fat mass (RFM), which combines height and waist circumference, does a better job of estimating overall body fat and predicting metabolic risks like heart disease and metabolic syndrome. Because those conditions share some underlying biological mechanisms with ADHD, researchers wondered whether RFM might also help explain the relationship between obesity and ADHD — particularly in children. 

That question is complicated by the fact that ADHD doesn't look the same in boys and girls. Boys tend to display more hyperactive and impulsive behavior, making their ADHD easier to spot. Girls more often show inattention, which is quieter and frequently goes undiagnosed. 


The Study: 

A new study set out to test whether RFM is associated with ADHD in children, and whether that association differs between sexes. Using data from the National Health and Nutrition Examination Survey (NHANES) collected between 1999 and 2004, the researchers narrowed a large initial pool of over 31,000 participants down to 5,089 children and adolescents aged 6 to 14 who had complete data on height, waist circumference, ADHD screening, and other relevant variables. 

After adjusting for age, race/ethnicity, Poverty-Income Ratio, maternal age at delivery, maternal smoking during pregnancy, health insurance coverage, and birth weight, the results revealed a striking split along sex lines.  

In boys, higher RFM was associated with lower odds of ADHD. Compared to boys in the lowest fat-mass quartile, those in the second quartile had about 10% lower odds of ADHD, rising to over 30% lower in the third quartile and nearly 40% lower in the highest. In girls, the pattern reversed entirely. While girls in the second quartile showed similar odds to those with the lowest RFM, girls in the third and fourth quartiles had 60% to 70% greater odds of ADHD. 

Conclusion & Why This Matters:  

In recent years, the relationship between obesity and ADHD has become an increasingly important focus in pediatric neurodevelopmental research. Studies have reported higher rates of ADHD symptoms among children and adolescents with obesity compared with their non-obese peers, and difficulties with peer relationships have also been linked to increased obesity risk (Sönmez et al., 2019). From a neurobiological standpoint, both conditions may involve shared underlying mechanisms, particularly dysfunction in dopaminergic pathways.

The authors concluded that higher body fat levels appear to lower ADHD risk in boys while raising it in girls. This finding highlights why sex-specific analysis matters in ADHD research. The underlying biological reasons for this divergence, however, remain an open question and open the door for future research.