Subclinical microcrania, subclinical macrocrarnia, and fifth-month fetal markers (of growth retardation or edema) in schizophrenia: a co-twin control study of discordant monozygotic twins.

Abstract

Summary: We tested the hypothesis that gestational injuries in some patients with schozophrenia would leave their mark as a subtle reduction in head circumference (subclinical microcrania). Conclusions: The head circumferences of all subjects were in the normal range. Decreased head circumference in affected MZ co-twins (relative to unaffected MZ co-twin) characteriazes discordant MZ pairs with larger finger-ridge-count differences (i.e., second-trimester fetal-size differences). This study using ideal genetic controls suggests that, while present only in some patients with schizophrenia, the decrease in head circumference is most likely a consequence of in-utero nonshared environmental deleterious events manifesting as groth retardation or as fetal edema and occurring around the fifth prenatal month