["Fifth day fits": a syndrome of neonatal convulsions. Can this condition be defined as an independent disease entity in Denmark?].

A 12-year retrospective study to elucidate the incidence of "fifth day fits" including 127 infants with neonatal convulsions was carried out in the Randers area of Denmark. The incidence of neonatal convulsions was 8.3/1,000 live-born infants. The etiology in 74 cases of latent and 53 cases of convulsive seizures was asphyxia (38%), intracranial hemorrhage (17%), hypoglycaemia (9%), hypocalcaemia (4%), infections (6%) and developmental defects (4%). In 28 cases (22%) the etiology was unknown. In only two of these cases, the seizures started on day 4-6, and no peak incidence was found.