Intrauterine growth linked to schizophrenia risk
MedWire News: Results from a Finnish study suggest that high and low birth weight and short and long birth length are associated with an increased risk for schizophrenia in later life.
"Several but not all studies have demonstrated that lower mean birth weight is associated with an increased risk of later schizophrenia," explain Kristiina Moilanen (University of Oulu) and team in the journal Schizophrenia Research.
But they add that the effects of high birth weight or birth length on risk for schizophrenia in later life were not known.
To address this, the team studied data on 10,934 individuals from the Northern Finland 1966 Birth Cohort - an unselected, population-based birth cohort from the provinces of Oulu and Lapland that has been followed up for more than 30 years.
Each participant's weight and length were measured at birth, and all those who developed schizophrenia by the age of 35 years were identified using the Finnish Hospital Discharge Register.
Low, normal, and high birth weight was defined as less than 2500 g, 2500-4499 g, and 4500 g or above, respectively, while short, normal, and long birth length was defined as less than 46 cm, 47-53 cm, and 54 cm or longer, respectively.
In total, 111 individuals were diagnosed with DSM-III-R schizophrenia by the age of 35 years.
After accounting for gestational age, gender, and parental history of psychosis, the researchers found that participants with a low or high birth weight were a respective 2.5 and 2.4 times more likely to develop schizophrenia in later life than those with a normal birth weight.
Similarly, individuals with a short or long birth length were a respective 2.6 and 1.8 times more likely to develop schizophrenia in later life than those with a normal birth length, after adjustment.
Moilanen and team conclude: "Our study has shown that deviant birth weight and length are characteristics that predict schizophrenia to a modest degree."
They add: "Further research involving larger cohorts with stored prenatal serum will enable the investigation of the role of hormones that control intrauterine growth and later brain maturation that may mediate the link with schizophrenia."
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By Mark Cowen