Final answer:
Alcohol consumption during pregnancy can cause fetal alcohol spectrum disorders, the most severe being fetal alcohol syndrome, characterized by distinct facial features and developmental issues. Alcohol can pass from the pregnant mother to the fetus and from the breastfeeding mother to the baby. Abstinence from alcohol is the only known way to completely prevent FASDs.
Step-by-step explanation:
Alcohol consumption during pregnancy can have severe impacts on the developing fetus. When a pregnant woman consumes alcohol, it can cross the placenta and enter the fetus's bloodstream, much like it does in the mother's body. This can lead to a range of developmental disorders known as fetal alcohol spectrum disorders (FASDs), with fetal alcohol syndrome (FAS) being the most severe form. Children with FAS can exhibit distinct facial features like flattened and thin upper lip, small palpebral fissures, and other growth and cognitive abnormalities. It's important to note that critical or sensitive periods exist during fetal development when organs and facial features are most susceptible to the effects of teratogens such as alcohol.
During breastfeeding, alcohol can also pass into the mother's milk and thus to the baby, potentially affecting infant development and behavior. While the immediate effects of alcohol on an individual, such as feelings of euphoria or sedation, vary with blood alcohol concentration (BAC), the consistent message from research is that no amount of alcohol during pregnancy or breastfeeding is considered safe. Therefore, the most effective way to prevent FASDs is complete abstinence from alcohol while trying to conceive, during pregnancy, and while breastfeeding.