Dr. Carson testified that she had not checked the military’s electronic record system for Mrs. Zeppa’s history, because all too often she had found patient records missing. In Mrs. Zeppa’s case, lab results were posted less than an hour after she left. Had she seen them, Dr. Carson testified, “I would more than likely have admitted her.”

Two days later, Mrs. Zeppa returned to the obstetrics and gynecology unit, insisting that she would not leave until she got warm. A nurse midwife, Kelly West, treated her with intravenous fluids and again released her. Ms. West testified that she did not review Mrs. Zeppa’s records either.

The next afternoon, with Mrs. Zeppa struggling to breathe, her mother summoned an ambulance. Mrs. Zeppa was airlifted the following morning to a civilian hospital in Oklahoma City, where she miscarried 10 days later and died the next month.

Five months after that, facing a malpractice claim, Reynolds officials conducted a risk-management investigation. In an interview, Ms. West, the nurse, said she had been cleared of violating the standard of care. Nor is there any public indication that the two doctors were penalized. They did not respond to requests for comment.

Medical experts hired by the family’s lawyers said that had the Fort Sill doctors recognized that Mrs. Zeppa was suffering from septic shock and immediately hospitalized and aggressively treated her, she and the baby probably would have survived. The government’s experts disagreed, noting that civilian doctors had been unable to save Mrs. Zeppa in five weeks of treatment.

Justice Department lawyers called Mrs. Zeppa’s death a “unique and tragic case, but not a case of bad and actionable medicine.” Beyond the risk-management assessment, they said, they knew of no other inquiry. Ms. West also said she knew of none in the roughly eight months before she left Fort Sill.

That left any missteps that contributed to Mrs. Zeppa’s death unexplained.

“She was really pretty, and she had a really big heart,” James Zeppa, Mrs. Zeppa’s husband, said. Now, he said, he no longer trusts military medicine.

Mrs. Zeppa’s father, Mike Amonett, had one thing to say about the Fort Sill hospital: “I just want that place shut down.”