Epidemiological evidence suggests that an adverse prenatal environment can have profound long-term health consequences throughout postnatal life. This chapter discusses the underlying mechanisms implicated in the consumption of mood-altering recreational drugs and teratogenicity in the fetus. The way metabolic parameters in pregnancy influence the pharmacokinetic characteristics of drugs and alcohol and the developmental stage of neurotoxicity are reviewed. The general underlying mechanisms that link multifaceted interactions between drug characteristics, gene polymorphisms, dietary deficiencies, changed endocrine indices and fetal programming are outlined, with specific examples throughout the text. As developmental injury is of significant social concern, the final section questions whether society provides adequate support for making appropriate and informed lifestyle choices to alleviate preventable transgenerational harm.