I was thinking the same thing, that the STD may be transmitted by the mother through the birth canal. However, the mother can be tested for everything under the sun during prenatal care, so I reject the “one size fits all” approach. Every newborn has drops put in the eyes to prevent syphilis. Makes no sense any more to do that routinely when the mom can be tested.
“... the mother can be tested for everything under the sun”.
I was tested for every STD imaginable while pregnant. The doctor advised me that birth involved a lot of “fluids” so they needed to know. I didn’t have an issue with it at all. Even while in labor, the staff asks about drugs/alcohol/recent piercings/tattoos/needle use etc... It is very common for any OB-GYN to test for an existing STD from his patient.