It was a foolish idea to make a sequel to a film which even today (mainly today) remains the best horror movie ever done.Patty Duke who was a wunderkind when she was a child (remember "the miracle worker")was given a poor part and she was sadly unsupported by the rest of the cast (if my memory serves me well,only Ruth Gordon remained from the original cast).
In order to give this dud a "biblical" feel ,the story is divided into "books" (the book of Rosemary;the book of Adrian ;the book of Andrew).The flick begins with the impressive last lines of Polanski's work (You want me to be HIs mother?/Aren't you His mother?) You do not need anything else when you've seen the 1968 film.
Ira Levin ,who had nothing to do with this made-for-TV sequel,wrote in 1999 "son of Rosemary" which was not as successful as his first novel:the conclusion ,they say,has an "hidden " meaning based on a pun.I've been trying to solve it for months ,to no avail..Anyway Levin should not have written it in the first place.
I finally found it out:nothing to get hung about.