In the pantheon of films about teenage pregnancies, Juno stands apart. It deals with its subject matter smartly, credibly and affectionately, never losing its sense of humor or its sense of heart.

Sixteen-year-old Juno MacGuffs (Ellen Page) pregnant predicament comes after one night when, bored, she loses her virginity to her best friend, Bleeker (Michael Cera), an awkward, gangly nerd with a gentle, decent nature.

After a brief flirt with the free-clinic alternative, Juno decides to carry the baby to term, then give it up for adoption a move supported by her unusually supportive parents (J.K. Simmons and Allison Janney).

Juno meets with the new parents, Mark and Vanessa Loring (Jason Bateman and Jennifer Garner), an affluent couple who longs for a child. All seems right and rosy, but its not. And Juno, who is intent on providing a good life for the baby shes about to birth, comes up with a progressive, undeniably sensible solution.

Diablo Codys screenplay is bittersweet, fostering an authenticity frequently lacking in Hollywood films.

Juno wouldnt be half as terrific if not for the wondrous Page, who portrays the title character as wry and knowing beyond her years. Page is also smart enough to let vulnerability seep through Junos seemingly tough veneer. The young actress, who made a splash in the revenge thriller Hard Candy, carries the film like a champ.

Of course, she has help. Cera continues to tap into his gift of stuttering, teenage discomfort.

Contact the writer at rshulman@metroweekly.com