A new study assessed risk factors for attention-deficit/hyperactivity disorder (ADHD) and determined that both preterm birth and poor fetal growth were risk factors for the condition. The study was published online on August 24 in the journal Pediatrics by Finnish and Swedish researchers.
The study authors noted that previous studies have reported an association between prematurity and ADHD. However, studies looking into the relationship in late preterm infants have produced conflicting results, and that studies examining fetal growth as measured by weight for gestational age are rare. Therefore, the aim of the study was to assess the association between gestational age by each week of fetal maturity, weight for gestational age, and ADHD.
The study group comprised 10,321 individuals with ADHD, diagnosed according to the International Classification of Diseases and 38,355 controls who were individually matched for gender, date and place of birth. The data was derived from Finnish nationwide registers. The source of perinatal data was the Finnish Medical Birth Register. The data was subjected to statistical analysis to determine the relationship between gestational age, weight for gestational age, and ADHD.
The researchers found that the risk of ADHD increased by each decreasing week of gestation. The associations remained strong after adjusting for confounders (factors that could skew the data). An increased risk was also found among late preterm and early term infants. In regard to fetal growth, an increased risk for ADHD was found when the weight for gestational age was 1 standard deviation below and or 2 standard deviations above the average.
The authors concluded that their findings suggested that each gestational week has significance for a child’s subsequent neurodevelopment and risk for ADHD. They also found that poor fetal growth increased the risk of ADHD. This finding underscored the importance of taking into account both prematurity and poor fetal growth when planning the timing of birth as well as later follow-up and support policies.
The authors are affiliated with Departments of Child Psychiatry, and Pediatrics, University of Turku, Turku, Finland; Departments of Pediatrics, and Child Psychiatry, Turku University Hospital, Turku, Finland; National Institute for Health and Welfare, Helsinki, Finland; and Nordic School of Public Health, Gothenburg, Sweden
According to the Centers for Disease Control and Prevention (CDC), ADHD is one of the most common neurodevelopmental disorders of childhood. It is usually first diagnosed in childhood and often persists into adulthood. Children with ADHD may have trouble paying attention, controlling impulsive behaviors (may act without thinking about what the result will be), or be overly active.
It is normal for children to have trouble focusing and behaving in occasion; however, children with ADHD do not grow out of these behaviors. The symptoms continue and can cause difficulty at school, at home, or with friends.
A child with ADHD might:
- daydream a lot
- forget or lose things a lot
- squirm or fidget
- talk too much
- make careless mistakes or take unnecessary risks
- have a hard time resisting temptation
- have trouble taking turns
- have difficulty getting along with others
Take home message:
Preterm birth and poor fetal growth can be prevented or minimized in many instances. Healthy lifestyle choices such as avoiding tobacco and alcohol, as well as high-quality prenatal care are extremely important.