Cerebral Palsy Among Children Born Moderately and Late Preterm

OBJECTIVE: To compare the incidence of and risk factors for cerebral palsy (CP) in moderately preterm (MP) (32(+0) -33(+6) weeks) and late preterm (LP) (34(+0) -36(+6) weeks) infants with those in very preterm (VP) (, 32(+0) weeks) and term infants (>= 37 weeks). METHODS: The national register study included all live-born infants in Finland from 1991 to 2008. Infants who died before the age of 1 year, had any major congenital anomaly, or had missing data were excluded. A total of 1 018 302 infants were included in the analysis and they were analyzed in 4 subgroups (VP, MP, LP, and term) and 3 time periods (1991-1995, 1996-2001, and 2002-2008). RESULTS: By the age of 7 years, 2242 children with CP were diagnosed (0.2%). CP incidence was 8.7% in the VP, 2.4% in the MP, 0.6% in the LP, and 0.1% in the term group. The risk of CP was highest in the study period 1991-1995 in all groups. Factors predictive of an increased CP risk in the MP and LP groups included resuscitation at birth (odds ratio 1.60; 95% CI 1.01-2.53 and 1.78; 1.09-2.90), antibiotic treatment during the first hospitalization (1.63; 1.08-2.45 and 1.67; 1.13-2.44), 1-minute Apgar score,7 (1.70; 1.15-2.52 and 1.80; 1.21-2.67) and intracranial hemorrhage (7.18; 3.60-14.3 and 12.8; 5.58-29.2). CONCLUSIONS: The incidence of CP is higher in LP and MP infants compared with term infants. There is a nonlinear decrease in incidence over time and with increasing gestational age.