Depends on the city, you and your circle's life goals, and so on. As a recent parent I can say that I only maintain a few close friends whom I see sparingly. Between a full-time job, raising a child, and keeping a marriage healthy there isn't much time for much else.
If your social circle isn't interested in children then this isn't going to be much of a difference.
If your social circle isn't interested in children then this isn't going to be much of a difference.