It can also be comforting for those who are grieving, allowing them to achieve some form of control following an event that can leave people feeling helpless. “The sameness is a way to normalize the death. It is very important for people to say ‘I’m normal. Yes, I have lost a child. But I’m normal.’”

Stillbirth memorial videos have codified certain rituals in a relatively short time, compared to the centuries over which, for instance, the Catholic church influenced the funeral traditions still common in cultures influenced by Catholicism. Over the course of about 15 years, Dr. Bacqué says, YouTube has become a kind of virtual cemetery for parents experiencing stillbirth.

This is partly related to a greater openness to expressing grief publicly. Ten years ago, only women attended the support groups Dr. Bacqué ran for bereaved parents. Now there are equal numbers of mothers and fathers.

[Read more: A Device That Gives Parents of Stillborn Babies Time to Say Goodbye]

Of course, not all parents experience stillbirth the same way. Posters of stillbirth memorial videos on English-language YouTube and Dailymotion tend to be white and North American, Dr. Bacqué said. But black Americans are twice as likely as white Americans to give birth to a stillborn child.

New Informal Rituals

Though the majority of stillbirth memorial videos shared via social media follow the now-established conventions, some parents are creating their own forms of filmed tributes.

Like Mrs. Franco-Pineda, Brian Fisher, a Michigan graphic designer, is used to documenting his family’s life. His YouTube channel is full of vacation videos featuring him and his wife, Kaytee. He’d been collecting lots of footage during her pregnancy, when they learned that their daughter, Elliott Rose, had a lethal form of skeletal dysplasia that meant she would survive only a short period after birth. It was a painful decision, but the Fishers chose to carry Elliott to term.

Ms. Fisher told me that now, two years later, “I’m so grateful for that time. We carried her for seven more weeks after the diagnosis before she was born and we fit a lot in to that time, and it allowed us to start grieving while she was still here.” This included Mr. Fisher’s special project of recording each step of the process, to complete the video in time for the memorial service, two weeks after Elliott’s birth and death.