Pam Ewing, the original “Dallas’s” heroine, and Pamela Barnes, her namesake niece on TNT’s sequel series, have more than a name in common. Both women marry into the Ewing family, both experience awkward introductions to life at Southfork, and their first encounters with J.R. are equally tense. Most notably, Pam and Pamela also suffer tragic miscarriages that send both of them to the edge — literally.

Pam’s quest to become a mother is a recurring theme of “Dallas’s early years. She and Bobby are overjoyed when they discover she’s pregnant at the end of the first season, but their parental dreams are dashed when Pam falls from the hayloft and suffers a miscarriage. She gets pregnant again at the beginning of Season 3, only to lose that child during another ranching mishap. Pam shifts her focus to her career, but when Sue Ellen leaves Southfork and takes John Ross with her at the beginning of Season 5, Pam’s memories of her miscarriages resurface.

Pam soon slips into a deep depression, alarming Bobby. At one point, he goes to visit his wife at The Store, the luxury retailer where she works, only to find her sitting in the baby department, holding a music box and lost in her thoughts. Then, in “The Sweet Smell of Revenge,” Pam goes to the roof of a tall building and contemplates jumping off. Bobby rescues her and brings her home to Southfork, where he urges her to get psychiatric help. “Honey, I’m worried about you,” he says.

Pamela has similar experiences on TNT’s “Dallas,” although the echoes are faint. Not long after she marries Christopher, the son that Bobby and Pam eventually adopted, Pamela becomes pregnant with twins. When Christopher discovers Pamela has been keeping some big secrets from him — namely, that she’s Cliff’s daughter and Christopher’s cousin — he divorces her, leaving her to take up with another one of his cousins, John Ross. Then the unthinkable happens: Cliff engineers the explosion of a Ewing Energies rig with Pamela and the Ewings aboard, causing her to lose her unborn children.

“Let Me In,” one of the new show’s second-season episodes, chronicles the emotional fallout from Pamela’s miscarriage. The hour opens with alternating shots of Christopher tearing down the nursery at Southfork while Pamela decorates the room she had set aside for the babies in her home. The montage ends with her sitting alone in the room, holding a stuffed animal and wearing a blank expression — not unlike Pam’s scene in The Store’s baby department. Later, John Ross comes to Pamela’s penthouse and finds her sitting on the balcony, entranced. She isn’t suicidal, but it nonetheless brings to mind Pam standing atop the tall building. (Indeed, “Let Me In” scriptwriter Aaron Allen has said he took inspiration for this scene not from “Dallas,” but from the 1985 film “St. Elmo’s Fire.”) In the next scene, John Ross brings Pamela inside and expresses his concern for her (“We are all worried about you”), just like Bobby did with Pam after her breakdown.

The question is: Will the parallels end here? On the original show, after Bobby and Pam adopt Christopher, she recovers her mojo, although her maternal struggles continue to haunt her. When Bobby briefly reunites with old flame Jenna Wade and impregnates her, Pam must learn to live with the fact that her husband will have a child with another woman.

Now that Pamela is married to the adulterous John Ross, we wonder: Will she soon find herself following in Aunt Pam’s footsteps yet again?

‘Honey, I’m Worried About You’

Let him help

In “The Sweet Smell of Revenge,” a fifth-season “Dallas” episode, Bobby (Patrick Duffy) sits in his bedroom reading a newspaper while Pam (Victoria Principal) sleeps on the bed.

PAM: [Awakens] Bobby?

BOBBY: Yeah, honey?

PAM: I’m sorry.

BOBBY: Oh, don’t worry. How do you feel?

PAM: [Pause] All right.

BOBBY: [Sets down his paper, moves to the bed and sits near her] Pam, we got to talk.

PAM: I know.

BOBBY: About you, about the future.

PAM: I know.

BOBBY: I spoke to Dr. Conrad. She said she already talked to you about voluntary commitment to Brooktree.

PAM: Yes, she did.

BOBBY: Well, she wanted to know how I felt, and I said I wanted what was best for you. She said that, at the present, she thinks that is the best. And with 24-hour-a-day care, you could overcome your problems a lot sooner.

PAM: Because you think I should be watched in case I try to kill myself again?

BOBBY: Pam, that’s not what I said.

PAM: But that’s what you meant.

BOBBY: Honey, I’m worried about you, and I care about you, and I don’t want what happened before to happen again. Now, if it’s going to be better — or safer — for you to be at Brooktree for a time, time enough to overcome this depression, then that’s what I want … for you. [Silence] Pam?

PAM: [Closes her eyes] I’m tired.

BOBBY: [Sighs] Well, you think about it, all right?

She nods.

‘We Are All Worried About You’

Let him in

In “Let Me In,” a second-season “Dallas” episode, John Ross (Josh Henderson) finds Pamela (Julie Gonzalo) sitting on the balcony of her apartment, brings her back inside and sits with her on the sofa.

JOHN ROSS: Where’s Afton? I thought your mother was taking care of you.

PAMELA: [Looking away] I sent her home … last week.

JOHN ROSS: Why’d you lie to me? [Silence] I think you should not be alone right now, Pamela.

PAMELA: I don’t care.

JOHN ROSS: Where’s your father?

PAMELA: Somewhere, making some deal. He sent me flowers.

JOHN ROSS: When was the last time you ate?

PAMELA: [Looks at him] Why are you here?

JOHN ROSS: I’m here because we are all worried about you. And I ain’t going anywhere until I know that you’re okay.

PAMELA: You’ll be here a long time.

JOHN ROSS: I’m going to go make you some tea. [Rises and exits as she closes her eyes]

How do you feel about Pam and Pamela’s painful losses? Share your comments below and read more “Dallas Parallels.”