As a nation state, Italy has emerged only in 1871. Until then the country was politically divided into a large number of independant cities, provinces and islands. The currently available evidences point out to a dominant Etruscan, Greek and Roman cultural influence on today's Italians.
My Calabrian grandmother had twins, but I do not know if they lived awhile or were stillbirths, or what. I began to look for a source to tell me when Italy began registration of stillbirths. This is from the World Health Organization (copied/pasted) via Tendenze evolutive della mortalità infantile in Italia, Annali di Statistica, Serie VIII, Volume 29. Rome: ISTAT; 1975.
"Registration of stillbirths began in Italy in 1863. But the low level of national SBRs and the regional differentials indicate that the process was far from comprehensive. In the 1870s only seven Italian regions had SBRs over 30, and in four (Abruzzi, Calabria, Sardinia and Sicily) it was less than 20. ... National SBRs only reached credible levels during the early decades of the 20th century ..."
I do not know how they would have classified these registrations (such as in Nati, Morte, Processetti, etc). Nati Morto? I found a surprise Recognizione in a FHC tape of morte. Right at the end was "Diversi" that was not listed as part of the film description -- maybe there. Thought this info might help others complete their histories.
Looking for Biagianti, Modesti & Vincenti in Tuscany and Tomaino, Curcio, Mazza, & Rizzo in Calabria
In Campobasso, the Morti-Nati records, 1812-1865, were registered as part of the Diversi records. After 1865, once again in Campobasso, these records are found among the birth records, labeled "bambino (or bambina, as the case may be) senza vita." I would suggest that you check the diversi records.