Objective: To evaluate the effects of intrauterine growth restriction (IUGR) with absent or reversed end-diastolic blood flow in the umbilical artery and very preterm birth on cognitive outcome at 5 to 8 years of age.
Methods: We studied 34 children with IUGR born at a median of 26.9 gestational weeks (GWs) (range: 24-29 GWs) (PT-IUGR), 34 matched preterm appropriate-for-gestational age (PT-AGA) children, and 34 term AGA children (T-AGA) by using the Wechsler Preschool and Primary Scale of Intelligence, Wechsler Intelligence Scale for Children, Strengths and Difficulties Questionnaire, and Brown's attention-deficit disorder (ADD) scales.
Results: The PT-IUGR group had mean (SD) scores on the verbal IQ (VIQ) and full-scale IQ (FSIQ) of 83.8 (17.3) and 78.9 (16.6), respectively, compared with the PT-AGA group, which had scores of 96.0 (14.5) and 90.1 (14.2) (P = .003 and P < .007), and the T-AGA group, which had scores of 101.3 (12) and 102.9 (13.2) (P < .001 and P < 001), respectively. The VIQ difference remained significant after adjustment for parental level of education, gestational age at birth, and neonatal morbidity. Performance IQ (PIQ) did not differ between the PT-IUGR and PT-AGA groups; their mean PIQs were lower than that of the T-AGA group (P < .001). Boys in the PT-IUGR group scored lower than girls in VIQ and FSIQ (P = .005 and .007, respectively). Behavior and ADD scores did not differ between the preterm groups.
Conclusions: Children born very preterm after IUGR have an increased risk for cognitive impairment at early school age compared with children delivered very preterm for other reasons. Differences in cognitive outcome were restricted to boys who may have been especially vulnerable to the influence of IUGR and very preterm birth.