Final answer:
The question asks about the risks substances present to fetuses during pregnancy based on animal and human studies. Regulatory bodies evaluate these risks with special regard to pregnant women and children. Known risks like alcohol and rubella are contrasted with others (e.g. hair dyes, E-fields) which currently show no evidence of increased risk.
Step-by-step explanation:
The question pertains to the safety and risk assessment of certain substances or conditions on fetuses during pregnancy. When studies on animal models such as mouse and rat suggest no risks to the fetus, medical researchers may use this data to develop hypotheses about human health outcomes. In such cases, regulatory bodies like the FDA (Food and Drug Administration), the EPA (Environmental Protection Agency), and the CDC (Centers for Disease Control) provide guidance and evaluate these substances for their safety profile in humans, with special attention to vulnerable groups like pregnant women and children under six. For example, certain compounds in dental amalgams could pose allergies but have not been found to cause risks to pregnancy by the FDA, in line with EPA and CDC opinions. Moreover, while infections like rubella and substances like alcohol are known to lead to congenital disorders or fetal alcohol spectrum disorder, other exposures such as hair dyes and electromagnetic fields have not been associated with increased risks of birth defects or cancer, respectively, per reports from relevant health organizations.
Nevertheless, it is crucial to understand that every substance and its potential impact on pregnancy must be evaluated individually, and what is considered safe is subject to change based on ongoing research and evidence. Therefore, when in doubt, consulting healthcare providers for the latest information and personal health advisories is recommended.