The prenatal risk factors of schizophrenia-spectrum disorders : focusing on the impact of high birth weight on obstetric complications

Abstract

A high birth weight (HBW) has quite recently been associated with an increased schizophrenia risk, but the link between a low birth weight (LBW) and schizophrenia is well-known. The purpose of this study was to analyze obstetric adversities – with the focus on the role of HBW - among 109 subjects chosen from the Finnish schizophrenia family study sample. The subjects had a schizophrenia-spectrum disorder or a genetically high risk of developing such a disorder. HBW (≥4000 g, n=37), compared to normal birth weight, NBW (2600-3999, n=64), associated with post-term pregnancy (p=0.041) and higher maternal parity (p=0.017). Post-term pregnancy associated with labour complications (p=0.04) and a prolonged first stage of labour (p=0.003). A higher parity was associated with Caesarean section (p=0.009), prematurity (p=0.048) and fetal malpresentation (p=0.021). LBW (<2600 g, n=8), compared to NBW, associated with perinatal complications (p=0.017), twin pregnancy (p=0.002), prematurity (p=0.009) grand multiparity (p=0.019) and higher parity (p=0.002)