Background. Many previous studies have shown that individuals who develop schizophrenia in adult life are more likely than normal controls to have a history of obstetric complications (OCs) at birth. However, little attention has been paid to the involvement of OCs in the risk of developing childhood-onset schizophrenia (COS). In our earlier report, we found an association between OCs and the development of COS. In this study, we determined whether the association could be replicated in another, independent set of patients with COS.

Methods. OCs, birth weight and gestational age were retrospectively assessed in 35 children, aged between 14 and 15 years old (average 15·4 years), who met the DSM-III-R criteria for schizophrenia, and in age- and gender-matched controls (children with anxiety disorders).

Results. The COS patients showed significantly greater scores in all of the three measures of OCs according to the Parnas et al. scale compared to controls. Moreover, individuals exposed to OCs were about 3·2 times (odds ratio = 3·22; 95% confidence interval, 1·1–9·8) more likely to develop schizophrenia than those without a history of OCs. The mean birth weight was significantly lower in schizophrenics than in controls (P < 0·05). The frequency of prematurity signs with weight < 2500 g was significantly higher in schizophrenics than in controls (P < 0·05).

Conclusion. Repeatedly reported association between OCs and adult-onset schizophrenia have also been demonstrated in patients with COS. This suggests that there may be a continuity between childhood- and adult-onset schizophrenia.