No.
The endings take into account her relationship level, her trainings (if any), and her birth control status and pregancy score. If they are at 120+ relationship, 100% Pregnancy score, there will be a good pregnant ending with at least one of the girls. So if all girls have 120+ relationship, you will have a good ending. The rest of it depends on 3 choices you make during the ending and the scores of pregnancy, birth control, trainings, etc.
Edit.. Clarify- 120 relationship/slut score means she's "mindless fuck toy" and that's what you want in a girlfriend, right?