Read the first part of the discussion, "Who Knocked Up Lady Gaga?"
Allow me to answer your questions with another question. You've wondered if Gaga's seeking motherhood without the inconvenience of heterosexual sex—but what I'd like to know is whether Gaga wants any sex at all, period.
After all, her music videos have expressed a fairly dim view of heterosexual sex: If it's not leading to someone's fiery death ("Bad Romance"), it's landing Gaga in the hospital ("Paparazzi"), or an act conducted by two skeletal zombies ("Born This Way"). And despite her profession of bisexuality, I haven't seen much evidence that Gaga considers lady love to be superior to the straight sort—in fact, it seems largely absent from the universe she inhabits. Both "Born This Way" and "Alejandro" (Gaga's explicit and implicit anthems to sexual freedom, respectively) communicate their celebratory message with gay male iconography; Gaga's most prominent instance of getting it on with girls takes place in the yard of a women's prison ("Telephone"), and it feels far more about power than about desire.