Having spent a bunch of time around new parents, my observation is that most of them are way too hyped up about trivial threats. If a breast-feeding mother drinks a glass of wine once every few days the risk to the baby is trivial. If the baby sleeps in the same bed with the mother the risk to the baby is trivial, unless the mother is an a severe alcoholic or high on drugs. If the baby plays with many types of toys marked “ages 3+” while the parents are sitting watching, the risk to the baby is trivial. If the baby climbs up on a play structure marked “ages 4–7” while the parents are standing watching, the risk of permanent injury is trivial. If a 2-year-old walks around barefoot on the sidewalk, the risks are trivial. Etc.
The same kind of tendencies bring us the anti-vax movement, a rush to sanitize all surfaces in the home, excessive fears about kidnapping, theatrical demonstrations of disgust near smokers outside on the sidewalk, and so on.
New parents’ (and people’s in our society more generally) risk assessment and concept of hygiene is excessively black–and–white.
But this is not the fault of “modern medicine”.