The slight man with tears running down his cheek had come to Woodhull Hospital in Brooklyn to visit his newborn son, Anuel, in the neonatal intensive care unit and plead for permission to take him home.

“You got me feeling like you all are holding my kid hostage,” said the man, Jose Perez, to a hospital social worker.

The social worker, according to an audio recording, explained yet again why the baby had to stay: The hospital needed additional proof Mr. Perez was the father. “Because mom is not present, you were unable to sign the birth certificate,” she said.

Not present.

The mother, Christine Fields, had not been present for more than a week. Mr. Perez, her fiancé, had been by her side as she bled to death in the hospital after giving birth.

Ms. Fields’s birth plan had declared him the father, but, critically, she had died before filling out a birth certificate. And with no official document, the hospital would not let him take his son home.

“You all don’t know how you all are making me feel,” Mr. Perez told the social workers. He told them about the couple’s two other children, Liam, 5, and Nova, almost 3: “They’re asking me for their baby brother.”