Reuben Wright Aug 13, 2019:

On formal documents, such as birth certificates, there will often be boxes to tick or into which to write a number to describe a birth by how many individuals were born on the occasion of the birth; single, double, triple, etc. And, not to be gruesome, but there are sometimes babies who are not born alive in the case of a multiple birth, and so there may also be a box for number born "dead" and number born "alive".

Juan Jacob Aug 13, 2019:

Pues nunca había escuchado "parto doble". Supongo que es el nacimiento de gemelos, y ya.