Pregnant women have been consuming all kinds of food for centuries.
We also took insane child mortality numbers and all kinds of defects for granted.
Our mothers still consumed food that has a tendency to contain/grow listeria. Then it was found in several cases where the reason for the death of the child was not known.
Now pregnant women (at least in Europe) are strongly advised to avoid products from raw milk and uncooked meat (hams and salami.
Things change, and not without a reason.