The prenatal period is recognised as a critical period for later behavioural development. This study aimed to elucidate how an adverse prenatal environment, as defined by the presence of a number of known prenatal risk factors, would influence mental health trajectories in children to 14 years of age. The Raine Study provided comprehensive data from 2,900 pregnancies. Offspring were followed up at ages 2, 5, 8, 10, and 14 years using the Child Behaviour Checklist (CBCL). We used linear mixed regression models with random intercept and slope (random effects models) to examine the extent to which the predictor variables considered influenced changes in continuous CBCL total, internalising, and externalising T scores from ages 2 to 14. In the final multivariate models, increased offspring CBCL T scores were significantly predicted by the mother not finishing high school, smoking during pregnancy, having a total family income below the poverty line, being diagnosed with gestational hypertension and experiencing stressful life events during pregnancy. Conversely, as maternal age increased, CBCL T scores were significantly decreased. Child age also significantly interacted with maternal education, total family income, and maternal stressful life events, such that these variables predicted increases in CBCL scores from age 2 to age 10, and from age 2 to age 14 years. In the Raine Study sample, children who experienced adverse prenatal environments experienced increased levels of problem behaviours in childhood, and more problematic mental health trajectories. Maternal health risk behaviours and other psychosocial variables more commonly affected child behaviour than obstetric complications.