Preterm Birth and Attention-Deficit/Hyperactivity Disorder in Schoolchildren

Abstract

OBJECTIVE: Previous studies have demonstrated an increased risk for attention-deficit/hyperactivity disorder (ADHD) in follow-up studies of preterm survivors from NICUs. In this study we analyzed the effect of moderate as well as extreme preterm birth on the risk for ADHD in school age, taking into account genetic, perinatal, and socioeconomic confounders. METHODS: Register study in a Swedish national cohort of 1 180 616 children born between 1987 and 2000, followed up for ADHD medication in 2006 at the age of 6 to 19 years. Logistic regression was used to test hypotheses. A within-mother-between-pregnancy design was used to estimate the importance of genetic confounding in a subpopulation of offspring (N = 34 334) of mothers who had given birth to preterm (≤34 weeks) as well as term infants. RESULTS: There was a stepwise increase in odds ratios for ADHD medication with increasing degree of immaturity at birth; from 2.1 (1.4–2.7) for 23 to 28 weeks' gestation, to 1.6 (1.4–1.7) for 29 to 32 weeks', 1.4 (1.2–1.7) for 33 to 34 weeks', 1.3 (1.1–1.4) for 35 to 36 weeks', and 1.1 (1.1–1.2) for 37 to 38 weeks' gestation compared with infants born at 39 to 41 weeks' gestation in the fully adjusted model. The odds ratios for the within-mother-between-pregnancy analysis were very similar. Low maternal education increased the effect of moderate, but not extreme, preterm birth on the risk for ADHD. CONCLUSION: Preterm and early term birth increases the risk of ADHD by degree of immaturity. This main effect is not explained by genetic, perinatal, or socioeconomic confounding, but socioeconomic context modifies the risk of ADHD in moderately preterm births.

Attention problems in relation to gestational age at birth and smallness for gestational age

“…Previous studies of attention problems were limited to specific periods of gestation, either the very preterm period, (3) late preterm period (7) or term-born Attention problems and gestational age 9 children only (36). Very few analysed the effect on attention deficit/hyperactivity disorder (ADHD) across the whole gestation spectrum and reported inconsistent findings (10,20).…”

“…Both head circumference (6,28) and family SES (20,29) have been previously reported to predict attention levels in children. Head circumference is a proxy measure of brain growth and was assessed at 5 months (corrected for gestation at birth) by research nurses who measured head circumference twice and the mean of both measures was recorded.…”

“…a birth weight below 10 th percentile) has been used as a proxy for FGR (17). SGA has been reported to significantly predict attention related problems in some studies (6,10,18) but not in others (8,19,20). Thus, while the link between very preterm birth and childhood attention problems is well established, the impacts of moderate/late preterm birth, SGA and elective caesarean birth are still uncertain.…”

Serotonin transporter polymorphism moderates the effects of caregiver intrusiveness on ADHD symptoms among institutionalized preschoolers

“…Also serving as a potential covariate were child preterm birth, obtained from children's medical records, and child sex, as all of these factors have been linked to ADHD symptoms (for instance, [54,55]). …”

Association of attention-deficit/hyperactivity disorder with diabetes: a population-based study

“…Therefore, by limiting our cases to those who received ≥3 ADHD diagnoses, we assured that all of our cases received a positive diagnosis based on their symptoms, medical history, and the results of at least one diagnostic test. We excluded patients who had been diagnosed with preterm births (ICD-9-CM codes 765.00-765.09, 765.10-765.19) or low birth weight (ICD-9-CM codes V21.30-V21.35) (n = 820), which have been reported to be risk factors for ADHD (7,8). In addition, we excluded patients who had been diagnosed with a congenital anomaly (ICD-9-CM codes 758.0-758.9, 759.9) (n = 41).…”