Sorry, I don't know any source in English (or Spanish). I remember reading about this on the Italian edition of the National Geographic and from some other reputable sources, but I can't pinpoint them precisely.

The practice of using suture stitches on the perineum in case of tearing due to childbirth is very ancient: it was already recommended as early as in the XI century by Trotula de Ruggiero, a woman medic from Salerno. I don't know if she was the very first to do that, and if I had to make a guess I'd say no.