This somewhat macabre story, from the beeb:http://news.bbc.co.uk/1/hi/science_and_environment/10384460.stm
The discovery actually dates back to the early twentieth century, although it seems to have only recently come to light.
From the article:
Archaeologist Dr Jill Eyers said: "The only explanation you keep coming back to is that it's got to be a brothel."
I don't know if Dr Eyers has further contextual evidence to back this up, but I'm somewhat sceptical of this hypothesis. Murdering and burying babies in situ
I understand the Romans took the concept of exposure from the Greeks, but would it be practised to this extent?