Neurodevelopmental outcome of premature infants born at less than 33 weeksof gestational age, with no cerebral palsy at the age of five years

Aim. - To appreciate the impact of prematurity fetal hypotrophy and familia l environment on the neurodevelopmental performances of very premature infa nts without cerebral palsy at the age of five years. Population and methods. - We followed a regional cohort of 171 very prematu re infants (less than or equal to 32 weeks of gestation) until they were fi ve years of age. Cognitive functions were tested with the WPPSI test and th e development quotient was assessed by the ability to draw a "bonhomme". Tw enty-two premature infants suffered from cerebral palsy diagnosed before th e age of two years. Another infant had a moderate diplegia at the five-year examination. We had no information for 16 prematures (9.3% of survivors). Twenty-eight premature infants were considered as having no severe disabili ty on phone or mailed contact, and another child had a severe isolated ment al retardation. We examined 104/148 infants, and 96/148 survivors without c erebral palsy passed the tests. The cognitive functions of these premature infants are compared to the performances of a control group made up of 108 children born at term greater than or equal to 37 weeks, matched for birthp lace and single or twin characteristics of the pregnancy. Results. - The values of the different quotients are significantly decrease d in the preterm group. The global IQ and the performance IQ are 0.8 SD, ve rbal IQ is 0.5 SD and the development quotient is 0.4 SD below the values o bserved in the control group. A performance IQ less than -2 SD for the mean of the control group is observed three times more than in the controls (13 .5% vs 3.7%, P < 0.01). Multiple linear regression shows that prematurity e xplains, independent of hypotrophy and socioeconomic environment, 8% of the variation of the performance IQ (P < 0.01), 2% of the variation of the ver bal IQ and 2% of the development quotient (P < 0.05). Conclusion. - The five-year neurologic outcome of the children born prematu rely in this regional study is similar to the results observed in regional studies conducted in Europe: 13.4% of the survivors have cerebral palsy, an d the cognitive functions of the children with no cerebral palsy are signif icantly lower than the term control group. Other risk factors such as hypot rophy, which modulates the developmental quotient, and the socioeconomic st atus, which modulates the verbal IQ, are underlined. (C) 2000 Editions scie ntifiques et medicales Elsevier SAS.