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

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.” 

 

Large Cohort Study Reports Association Between Eye Disorders and ADHD

Refractive errors, such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism (distorted vision due to irregular curvature of the eye or lens), are common worldwide. These conditions affect 12%, 5%, and 15% of children, and rise significantly in adults to 26.5%, 31%, and 40%. Additionally, strabismus (misalignment of the eyes) and amblyopia (reduced vision in one eye from uneven image formation, often linked to strabismus) occur globally at rates of 2% and 1.4%, respectively. 

Visual impairment can affect children’s concentration in school, and studies suggest a link between eye disorders and ADHD. 

To investigate this relationship, two researchers – one based in the US and the other in Israel –carried out a nationwide retrospective cohort study using electronic medical records of all insured individuals aged 5 to 30 who were part of Maccabi Health Services, Israel’s second largest health maintenance organization, between 2010 and 2022. 

Of over 1.6 million insured members (2010–2020), inclusion/exclusion criteria and propensity score matching for age and sex were applied, along with a one-year wash-out period between the first eye diagnosis and ADHD diagnosis. In total, 221,707 cases were matched with controls without eye disorders at a 1:2 ratio, resulting in a cohort of 665,121 participants.  

Overall, those with any previous eye diagnosis were 40% more likely to have a subsequent ADHD diagnosis. This was slightly higher for females (45%) than for males (35%). It was also slightly higher for children and adolescents (42%) than for adults (37%).  

More specifically: 

  • Myopia (425,000+ participants): 30% higher ADHD rate. 
  • Hyperopia (120,000+) and astigmatism (175,000+): over 50% higher ADHD rate. 
  • Strabismus (13,000+): over 60% higher ADHD rate. 
  • Amblyopia (14,000+): 40% higher ADHD rate. 

The authors concluded that eye disorders are associated with ADHD. They noted these associations were more marked in females and children and adolescents, although, as noted above, those differences were small. They recommended that primary care providers and neurologists consider risk stratification for early screening, and that ophthalmologists refer high-risk patients for ADHD evaluation. 

 

 

February 10, 2026

South Korean Nationwide Population Study: Prenatal Exposure to Acid-suppressive Medications Not Linked to Subsequent ADHD

Acid-suppressive medications, including proton pump inhibitors (PPIs) and histamine-2 (H2) receptor antagonists, are often prescribed during pregnancy to treat heartburn and gastroesophageal reflux disease. 

Research shows changes in the gut microbiome can negatively affect neurodevelopment. Since acid-suppressive medications alter gut microbiota, maternal use during pregnancy may impact offspring’s neurodevelopment. Because PPIs and H2 receptor antagonists readily cross the placental barrier, they could potentially influence fetal neurodevelopment.  

The link between prenatal exposure to acid-suppressive medications and major neuropsychiatric disorders is not well understood. With the use of these medications during pregnancy rising, it is important to assess their impact on children's long-term neurodevelopment. This study examined whether maternal use of acid-suppressive drugs is associated with increased risk of neuropsychiatric disorders in children, using a large, nationwide birth cohort from South Korea. 

South Korea operates a single-payer health insurance system, providing coverage for over 97% of its citizens. The National Health Insurance Service (NHIS) maintains a comprehensive database with sociodemographic details, medical diagnoses, procedures, prescriptions, health examinations, and vital statistics for all insured individuals. 

A Korean research team analyzed data from over three million mother-child pairs (2010–2017) to assess the risks of prenatal exposure to acid-suppressing medications. They applied propensity scoring to adjust for maternal age, number of children, medical history, and outpatient visits before pregnancy, to minimize confounding factors. That narrowed the cohort to just over 800,000 pairs, with half in the exposed group. 

With these adjustments, prenatal exposure to acid-suppressing medications was associated with 14% greater likelihood of being subsequently diagnosed with ADHD. 

Yet, when 151,737 exposed births were compared to the same number of sibling controls, no association was found between prenatal exposure and subsequent ADHD, which suggests unaccounted familial and genetic factors influenced the preceding results. 

The Take-Away:

Evidence of these medications negatively affecting pregnancies is mixed, mostly observational, and generally reassuring when these medications are used appropriately. Untreated GERD and gastritis, however, have known risks and associations with the development of various cancers. With no evidence of an association with ADHD (or for that matter any other neuropsychiatric disorder), there is no current evidence-based reason for expectant mothers to discontinue use of acid-suppressing medications.  

February 6, 2026