I suspect it was actually the pilot episode for Poltergeist: the Legacy as per this article.
"I am birthing evil incarnate," she explains, "and I'm being dragged around by the demon by its umbilical cord, because he didn't quite bank on the fact that once he's out he's still attached to me. That part's kind of horrifying and scary, but right at the end of it I open my eyes and what I see is my son who died a year ago, standing like an angel. Part of me is experiencing my dead son being reborn, so it's a really interesting scene, because this extreme violence of birth is also a kind of bliss. I'm sort of in a trance."
Excerpts from the Episode synopsis:
Connemara, Ireland. Rachel Corrigan and her young daughter, Kat, are visiting the gravesites of Rachel's husband son, Patrick & Conner. It's the one-year-anniversary of their death. As Rachel talks to the groundskeeper, Kat "hears" what she thinks is her brother calling for her to come to her. She runs off and winds up in an antique shop sitting next to an old box - the fifth sepulcher.
Connemara, Ireland. Back at the antique shop, its owner, Shamus Bloom, is looking for the key to the "box" because Rachel wants to buy it for Kat who says "it reminds her of Conner." He find the key later and shows up at Rachel's room at the inn to give it to Kat, but the lock is frozen. He takes the key and box back to his shop to fix it.
Shamus Bloom fixes the lock, turns the key and gets the surprise of his life as the demon enters his body and takes over.
Rachel & Kat are getting ready for bed. Shamus shows up with the "fixed" box and entices Rachel to turn the key to open it. In a mesmerized state caused by the demon, Rachel believes Shamus is her dead husband come back to life and he says he's going to give her son back to her. (You can guess how.) After it's too late, Rachel realizes this guy isn't her husband and screams which brings Kat to her room, who screams. Derek and Nick hear them and go running to the rescue. Nick chases after the possessed Shamus and shoots him. The spirit leaves Shamus body as a oozing rotting mass with maggots. (Yuck! I really hate maggots.) Derek and Nick then see Julia's "crucified" dead body on a scarecrow post in field.
Derek gives Kat the fifth key to safeguard because she's truly an innocent soul and the demon has no power over her. Rachel wakes up in an unreasonable state and abnormally pregnant. She thinks the Legacy is going to take her "baby" away and tries to leave but ends up going into labor. She gives birth to a demon who looks like her son Conner (so he can make his "Mommy" do what needs to be done for him) and goes about trying to assemble all the keys and the sepulchers.
So, no angel involved, but the demonic birth scene seems to match.
The birthing scene