Objective To determine whether birth and care in the highest-level hospitals (level III) compared with birth in or postnatal transfer to lower-level hospitals (level II) are associated with 5-year morbidity in very preterm children.

Design A cohort study.

Setting Finland.

Participants All surviving 5-year-old children born very preterm (gestational age <32 weeks or birth weight ≤1500 g) born in level II or level III hospitals (n = 2168) and full-term (gestational age, 37-42 weeks) children (n = 238 857) born from January 1, 2000, through December 31, 2004.

Main Outcome Measures Diagnoses issued after the first discharge home and overrepresented in very preterm compared with full-term children. Diagnoses were analyzed between very preterm children (1) born and treated in level III hospitals (group III), (2) born in level III and transferred to lower-level hospitals (group III/II), and (3) born and treated in level II hospitals (group II).

Results Group III/II children had an increased incidence of retinal disorders (odds ratio, 2.43 [95% CI, 1.66-3.56]) and asthma (1.41 [1.09-1.81]) but fewer viral infections (0.75 [0.59-0.95]) compared with group III infants. The risks for epilepsy (odds ratio, 2.71 [95% CI, 1.29-5.70]) and hyperkinetic disorders (2.19 [1.13-4.25]) were higher among group II than among group III children. No statistically significant differences between the groups for the 14 other diagnoses were found.

Conclusions The increased incidence of retinopathy and asthma among infants transferred from level III to lower-level hospitals calls for analysis of the differences in treatment practices between hospital levels.