What interest does society have in minimizing the harmful substances a pregnant person is exposed to?

Is it feasible and/or necessary to ask a pregnant person to change their behaviors (e.g., stop drinking alcohol, move to a location with fewer pollutants) in order to protect their developing embryo/fetus from possible harm? If you're stuck: Think about teratogens and the timeline over which teratogens have the greatest effect.

Identify one potential barrier to reducing pregnant people's exposure to harmful substances.

include references and intext citation please