Table 2.

Rh and other blood incompatibility and schizophrenia,.

Authors and year	Location	Type of study	N	Diagnosis	Finding
Hollister et al. (1996)	Denmark	Birth cohort study	21 male cases	ICD-8 diagnoses of schizophrenia determined through National Psychiatric Register	Rh incompatibility associated with a 2.78-fold increased risk of schizophrenia in male offspring. The risk was present only in second or later born offspring
Palmer et al. (2002)	Finland	Family-based candidate-gene study	181 cases	DSM-IV diagnoses of schizophrenia, schizoaffective disorder, or schizophrenia spectrum disorder (i.e., paranoid personality, schizoid personality, and schizotypy) determined by record review.	Incompatibility between maternal and fetal genotypes was associated with a 2.6-fold increased risk of schizophrenia
Insel et al. (2005)	Alameda County, California	Birth cohort study and analysis	71 cases	ICD-9 and DSM-IV diagnoses of schizophrenia spectrum disorders (SSD), including schizophrenia, schizoaffective disorder, delusional disorder, psychotic disorder NOS, and schizotypal personality disorder, diagnosed through diagnostic interview (Diagnostic Interview for Genetic Studies) and record review	Rh incompatible offspring had a 1.8-fold, though nonsignificant, increase in risk of schizophrenia; a significant sex by exposure interaction was observed, with a greater increase in male offspring. A modest increase in risk of schizophrenia was also observed for ABO incompatibility (involving a mother with blood type O and offspring with either A or B blood types), and a significant interaction effect was demonstrated between the sex and exposure