Final answer:
Exposure to alcohol and other teratogens, such as cigarette smoke and illegal drugs, during pregnancy can lead to fetal alcohol spectrum disorders and other severe developmental issues.
These risks underscore the importance of expectant mothers avoiding these substances to prevent long-term health problems for their children.
Therefore, the correct answer is: option 'alcohol'.
Step-by-step explanation:
When a baby is still in the mother's womb, exposure to certain substances can have significant developmental consequences. In particular, the consumption of alcohol by the mother can lead to fetal alcohol spectrum disorders (FASD).
These are a group of conditions that include cognitive deficits, developmental delays, and behavior issues. Exposure to teratogens, which are environmental agents like drugs and chemicals, during pregnancy can damage the developing embryo or fetus.
It's important to note that during the critical periods of organogenesis in the first 8 weeks post-fertilization, exposure to harmful substances can result in the most severe effects, potentially leading to lifelong consequences for the child.
Among the spectrum of teratogens, substances like cigarette smoke and illegal drugs such as heroin also pose serious risks. These can lead to complications like low birth weight, premature birth, and other serious and life-threatening conditions.
Therefore, it is crucial that expectant mothers avoid exposure to these teratogens to protect the developing baby from long-term health issues, including the risk of the child developing depression or other psychological conditions.