Prenatal infections, obstetric complications and schizophrenia

Objective: An association between prenatal exposure to influenza and adult schizophrenia was reported in the literature. We studied this association and the relationship of obstetric complications, another risk factor, in patients with schizophrenia. Method: We assessed infections during pregnancy, obstetric complications, gestational age and birth weight by interviewing the mothers of 103 patients with DSM-IV schizophrenia, using a structured interview. Results: Seventy-one males and 32 females were evaluated. Thirty-three mothers suffered from an infection and seventy did not. Five mothers suffered from influenza, 23 suffered from respiratory infections, 1 had gastro-intestinal infections and 4 had genito-urinary infection. In the second trimester significantly more infections (20 cases, 61%) were reported as compared to the first (4 cases, 12%) and third (9 cases, 27%) trimester (x2=13.60, DF=2, p0.03). Country of birth did not influence the distribution of infections. Obstetric complications were found in 68 patients. Heredity for schizophrenia was found in 45% of the patients. A significant difference was found between patients who suffered from infections as compared to those without infections when gestational age was grouped by obstetric complications (x2-21.01, DF= 1, p0.03). When infections were grouped by birth weight (divided into two groups: under 2.499 kg. and above 2.499 kg.) a statistically significant difference was found (Fisher exact test -2-tail -5.22' DF=1, p=0.02). Conclusions: Maternai infections during pregnancy, especially in the second trimester, may impair fetal growth and predispose to obstetric complications and lower birth weight in a proportion of individuals destined to develop schizophrenia.