Intrauterine growth and gestational age in preterm infants with cerebral palsy.

In a case-control study, gestational age and intrauterine growth of 191 preterm singleton infants 1971-82 with cerebral palsy were compared to all preterm live-born singletons in Denmark in 1982 (N = 2203). The distribution of gestational age among preterm cases was slightly bimodal with maximum values at 29 and 32 weeks. The risk for cerebral palsy was highest in the infants with gestational age 28-30 weeks (OR = 5.6 (4.0-7.8), 95% confidence interval). Birth weight deviation, in the 34-36 weeks infants, expressed as the number of standard deviations from the mean birth weight for gestational age, was more negative in cases than in controls (P < 0.001). The frequency of small for gestational age (SGA) was 13% in cases and 9% in controls (OR = 1.5 (0.96-2.3), 95% confidence interval). The odds for cerebral palsy being SGA, was lower in 28-30 weeks (OR = 0.22 (0.06-0.86), 95% confidence interval), the same in 31-33 weeks (OR = 0.83 (0.35-2.0), 95% confidence interval) and higher in 34-36 weeks (OR = 5.2 (2.9-9.5), 95% confidence interval). In conclusion, preterm infants with cerebral palsy are born earlier than other preterm infants. Small for gestational age is associated with cerebral palsy in preterm infants only above 33 weeks.