By Julie Jordan -
Marinoni gave birth to the couple's son, Max Ellington Nixon-Marinoni, on Monday, Feb. 7, Nixon's rep confirms.
"Christine and baby are doing great," her rep tells PEOPLE.
Nixon, 44, and Marinoni, 43, began dating in 2004 and announced their engagement in 2009. The Sex and the City star has two children, Samantha, 14, and Charles, 8, from her previous relationship with teacher Danny Mozes.
Cynthia has been very active in the push for marriage equality in New York State.