Sex and the City has a prequel series and it's called The Carrie Diaries. It's a one-hour drama that airs on CW. The series begins on Jan. 14th.

The show focuses on Carrie Bradshaw during her senior year of high school during the early 1980s and part of her life in New York working as a writer. - Wikipedia
Sex and the City characters could appear on new prequel series The Carrie Diaries. Carrie showrunner Amy B Harris told The Hollywood Reporter that while the CW drama's only current link to its parent series is Carrie (AnnaSophia Robb) herself, the likes of Miranda, Samantha and Charlotte could appear in future seasons. - 'Carrie Diaries' to introduce 'Sex and the City' characters?