Deviant intrauterine growth and risk of schizophrenia: A 34-year follow-up of the Northern Finland 1966 Birth Cohort

BackgroundLow birth weight conveys a modest risk for schizophrenia. The effects of high birth weight and deviant birth length are less clear.MethodsWe linked perinatal data from 10,934 subjects from the Northern Finland 1966 Birth Cohort (n = 12 058) to the Finnish Hospital Discharge Register where we identified 111 cases of DSM-III-R schizophrenia up to age 35 years. Adjusted odds ratios between the risk of schizophrenia and birth weight, birth length and ponderal index and the risk of schizophrenia were analyzed.ResultsBoth low (OR 2.5; 95% CI 1.2–5.1) and high birth weight (OR 2.4; 95% CI 1.1–4.9) increased the risk of later schizophrenia. In addition, short (OR 2.6; 95% CI 1.1–5.9) and long babies had an elevated risk of schizophrenia as adults (OR 1.8; 95% CI 1.0–3.5). A reverse J-shape curve described the associations between birth weight, length and schizophrenia.ConclusionsDeviant intrauterine growth of the fetus in either direction was associated with increased risk of schizophrenia.