Potential developmental effects of licit and illicit substances in humans: An approach to risk-specific dose and incidence.

Teratogens encompass any agent capable of causing a birth defect or elevating the incidence of defects within the population. This category includes substances like drugs, both legal and illegal. These substances cause congenital anomalies depending on the stage of development at the time of exposure, the dose, and the exposure time associated with the embryo. The most sensitive period is the embryonic stage, when the three leaflets give rise to tissues and organs. Susceptibility to teratogenesis decreases during the fetal phase but morphological and functional disturbance of the fetus may still occur. Substance use during pregnancy and its adverse effects are a public health problem and the lay population does not have access to this information. Particularly concerning is the period within the first six weeks of pregnancy, often before a woman realizes she is pregnant. Developmental data for many substances are simply not available, which makes the problem more serious. The aim of this study is to reflect on the teratogenic effects of licit and illicit substances in humans, focusing particularly on the dose that can induce malformations and their incidence in humans.