"I am SO IN LOVE with my son Lorenzo Dominic! I had my little man last night, healthy at 6lbs! HE'S MY WORLD!" she wrote on Twitter, then added a heart icon.
Polizzi, 24, and fiance Jionni LaValle had their baby shortly before 3 a.m. Sunday at St. Barnabas Medical Center in Livingston, N.J.
A Polizzi representative told MTV: "The world just got another Guido! Lorenzo Dominic LaValle has entered the world weighing 6 pounds, 5 ounces. Nicole, Jionni and Enzo are doing great!"
"Jersey Shore" created a bit of controversy when it debuted in 2009 for the willingness of eight 20-somethings sharing a Jersey Shore summer house to call themselves "guidos" and "guidettes." A "guido" is often viewed as derogatory for a working-class urban Italian-American man or sometimes for an Italian-American man who conducts himself in a thuggish, overtly macho manner.
LaValle wrote on Twitter Monday he didn't know "what I enjoy more, watching my fiance sleep or watching my son sleep," adding "Both are amazing! #Lafamiglia"
Other Twitter messages from Polizzi, who didn't let giving birth keep her from the social network, include:
-- "Being a mom is an amazing feeling!!! I love my little man to death! Jionni is such a cute dad."
-- "Hardly any sleep but SO worth it!"
-- "Post birth isn't so comfy and glamorous. But my son is fabulous."
-- "Im finally able to eat eggs again! While I was pregnant I couldn't even smell them! Now I'm killing it with egg whites!!! #YUM"
Polizzi is one of the highest paid reality stars, earning $150,000 per episode as of Season Five, which ended March 15. MTV confirmed the series would return for a sixth season.
She says she got the nickname "Snooki" in high school because she was the first of her friends to kiss a boy. Snooki was a male character in the 2001 MTV film "Save the Last Dance."