Are infants born after an episode of suspected preterm labor at risk of attention deficit hyperactivity disorder? A 30-month follow-up study.

BACKGROUND:An episode of suspected preterm labor may be by itself a pathologic event that may alter the normal course of pregnancy and the offspring's neurodevelopment. Certainly, the association between preterm birth and neurodevelopmental disorders can only be partially explained by the immaturity of the nervous system, as evidenced by the increased risk of attention deficit hyperactivity disorder in late-preterm infants without any neurologic alteration. OBJECTIVE:This study aimed to examine whether infants born after suspected preterm labor may be at an increased risk of developing attention deficit hyperactivity disorder. Moreover, potential obstetrical, perinatal, and psychosocial risk factors associated with attention deficit hyperactivity disorder in this population are examined. STUDY DESIGN:A prospective cohort study of 120 mother-infant pairs was conducted from the moment the mothers received a diagnosis of suspected preterm labor until the infants' 30 months of life. Infants were divided according to the prematurity status: full-term infants born after a suspected preterm labor (n=28; born at ≥37 weeks of gestation), late-preterm infants (n=56; born between 32 and <37 weeks of gestation), very-preterm infants (n=36; born before <32 weeks of gestation). At-term infants born without obstetric complications served as a control group (n=46). Infants' attention deficit hyperactivity disorder symptoms were assessed at the age of 30 months. Furthermore, obstetrical, perinatal, and psychosocial risk factors were recorded. RESULTS:All groups of infants born after a suspected preterm labor showed more attention deficit hyperactivity disorder symptoms at the age of 30 months than the control group. Concretely, very-preterm infants showed higher restless or impulsive behaviors, whereas full-term infants born after a suspected preterm labor and late-preterm infants showed higher emotional lability behaviors. Among potential risk factors, male sex and maternal experience of posttraumatic stress symptoms predicted the severity of attention deficit hyperactivity disorder symptoms in infants born after a suspected preterm labor. CONCLUSION:Infants born after a suspected preterm labor had a higher risk of developing attention deficit hyperactivity disorder symptoms, including those born at term. Infants born after a suspected preterm labor showed a distinctive phenotype and shared specific risk factors suggesting that they conform an undescribed population at risk of attention deficit hyperactivity disorder.