When the first letter from Women & Infants Hospital arrived in the mail in July 2017, Elaine Meyer thought perhaps it was a fund-raising solicitation or clerical error. The letter, which included a billing invoice, addressed her as “Dear Patient,” but she had not been a patient at the hospital for nearly two decades. That’s when she and her husband, Barry Prizant, had completed their infertility treatment there.

After three miscarriages, they had gone through several rounds of IVF at Women & Infants in Providence, R.I., near their home in Cranston, resulting in the creation of at least 18 test-tube embryos. One of those had become their son, Noah, born in December of 1996, and along with joy there had been a lot of mourning and reckoning with the reality that this would be the sole realization of their efforts.

Dr. Meyer mentioned the letter to her husband and stashed it in a filing cabinet of her home office.

But then another came the next month. “If you would like WIH to continue to store your embryos/oocytes,” the letter said, “please return a copy of this letter, signed and notarized, along with a check in the amount of $ 500.”

Dr. Meyer, a longtime psychologist at Boston Children’s Hospital and associate professor of psychology at Harvard Medical School, read it with confusion and a growing sense of alarm. Without the payment, the hospital would consider embryos “legally abandoned” and may discard them.

“I thought, ‘This can’t be right,’” she said. “We know we went back for all of our embryos.”

Those frozen embryos, still in the hospital’s possession, are now at the center of a lawsuit that Dr. Meyer and Dr. Prizant have filed in Rhode Island’s Superior Court, alleging breach of contract, negligence, bailment and intentional infliction of emotional distress — all of which Women & Infants denies in its response.

In a statement, a spokeswoman there declined to comment on the case, citing patient confidentiality and federal privacy laws.

When the letters arrived, Dr. Meyer and Dr. Prizant, a speech and language pathologist and visiting scholar at Brown University, were then fulfilled empty nesters. Noah was in college, a successful student and happy young man that Dr. Meyer, now 63, calls “the light of our lives.”

She was ensconced in her work educating students and health care professionals how to have difficult conversations with patients, upholding what she calls an “emotional standard of care.”

Dr. Prizant, 69, who specializes in children and adults on the autism spectrum, was training other practitioners and churning out papers and podcasts. He is the author of “Uniquely Human,” a book written with Tom Fields-Meyer. He plays drums in a band and is proud of his roots in the stickball streets of Brooklyn. “Basically, I don’t like to take crap,” he said.

He and his wife, a former 4H club member raised in a large working-class family in small-town Connecticut, met in 1985 while attending a conference at a psychiatric hospital. Married two years later, they wanted children but felt it was important for her to finish graduate school first. Dr. Meyer got pregnant at 34, then had a miscarriage. Two more miscarriages followed.

The couple first sought treatment from Dr. Gary Frishman at Women & Infants, which is affiliated with Brown’s medical school, in 1995. Dr. Prizant gave his wife daily shots before her eggs were harvested at the clinic and mixed in a petri dish with his sperm to create embryos, some of which were then implanted in Dr. Meyer’s uterus. The first two cycles didn’t work.

“It takes something that is supposed to be so private and so intimate and so tender and makes it a whole different affair,” Dr. Meyer said, recalling the experience. “You’re vulnerable and you’re completely dependent on other people. There are so many injections and appointments and disappointments, you put your trust in what the doctors tell you because you are desperate for the process to work.”

During a third cycle, Dr. Meyer became pregnant with Noah. After his birth, she and her husband were optimistic they could have another child. There were nine embryos left over from the three cycles, and they signed agreements with the hospital to “cryopreserve” them for implantation in the future.

Dr. Meyer felt an acute attachment to the embryos, calling each “a spark of life.” She would drive out of her way to pass by the hospital, stopping in the parking lot to sing lullabies to them while in her car. “We were always coming back for our embryos,” she said. “That was always the plan.”

After Noah started preschool, the couple began anew at Women & Infants in August of 2000 with shots and doctor appointments. The hospital would thaw the nine embryos, and those that survived this process would be implanted in Dr. Meyer’s uterus, in the hopes that at least one would develop into a pregnancy.

The couple said they were told all the embryos were thawed; they believe three survived the thaw and were implanted. But weeks later, they were called in for “the failure conversation” — what Dr. Meyer called the meetings with doctors to discuss an unsuccessful procedure and possible next steps.

This one was with Dr. David Keefe, then the director of the hospital’s division of reproductive medicine. He advised Dr. Meyer that at 43, her and her husband’s most reasonable path to additional children was donor eggs or adoption.

Dr. Prizant was done, emotionally exhausted. “It sets you in a constant state of grief,” he said of infertility treatment.

Dr. Meyer, a devoted Quaker, needed a little more time and spiritual consultation, but also made peace, grateful for Noah. “We both decided,” Dr. Prizant said, “to look at having just one child as an opportunity to have more resources to serve many more children through our work.”

A Crack in the Glass

Reading the second letter, which like the first one asked for $ 500, filled Dr. Meyer with dread. She left a voice mail message at the hospital. Days later, she spoke to a person who turned out to be a clerk in the billing department.

“I am telling you, there are no embryos,” Dr. Meyer said, asking her to contact the lab itself.

For weeks, she waited for a call back. Nothing. She called the clerk again. “I’ve confirmed with the lab, there are two frozen embryos,” the clerk said.

Ms. Meyer was stunned, silent. Then she spoke. “Do you understand how serious this is?” she said.

A few days later, she was driving back from the family cottage in South Kingstown, when Dr. Ruben Alvero, then the director of the fertility center at Women & Infants, called to confirm. “We have two of your embryos,” he said.

She pulled her car to the side of the road.

The embryos, Dr. Alvero said, had been found in a glass vial at the bottom of the tank. The vial has a crack in it, he told her, which meant that the embryos had been exposed, possibly for a decade, to the nitrogen cooling agent. They most likely are not viable, he told her, and apologized.

Dr. Meyer told Dr. Alvero this was too much to take in from the side of the road. A meeting was arranged for December of that year, between Dr. Meyer, her husband, Dr. Alvero and Richard Hackett, who helped to create and manages the I.V.F. lab at Women & Infants. Dr. Frishman, who had been Dr. Meyer’s main doctor and is still on the staff at Women & Infants, did not attend.

The four gathered in a conference room, with Dr. Prizant and his wife on one side, Dr. Alvero and Mr. Hackett on the other.

According to the legal complaint, the men representing the hospital apologized for the circumstances that had brought them together and explained to the couple again what had happened. Two of Dr. Meyer and Dr. Prizant’s embryos had disappeared sometime before Dr. Meyer’s procedure in 2000, Dr. Meyer said they told her and her husband. The embryos were located in 2010 when the tank was emptied for cleaning or maintenance and re-entered into the inventory. The vial, as Dr. Alvero had told Dr. Meyer earlier in the fall, had been damaged. When the clinic implemented a new storage fee policy in 2017, the couple received the bills.

She asked if the cells of the embryo still physically existed. They did, the men told her. Though likely compromised, the embryos are still intact, in their glass vial with her name on it.

“Those are ours!” Dr. Meyer blurted out, and said that she didn’t want the embryos discarded. Dr. Alvero told her that the hospital would continue to store them and that he would waive the $ 500 fee. He and Mr. Hackett apologized and flipped through pages in her huge medical file, which the men had brought to the meeting. Mr. Hackett stopped on one page, she said, and began tapping his fingers on it: a handwritten note that said “2 missing.”

“You knew they were missing” and didn’t tell us, Dr. Meyer asked?

No one ever tried to find the embryos, or thought to alert us when they were found years later, Dr. Prizant asked?

Perhaps the couple forgot that they had been told that the embryos were missing, they said Dr. Alvero suggested.

Dr. Prizant and Dr. Meyer were sure no one had ever told them anything was missing. Why would they have discussed adoption and egg donation if they had known two embryos were lost in the hospital? “That would have set us on a different course of action,” he said.

Dr. Keefe, a professor of obstetrics and gynecology and a fertility specialist at New York University Langone Fertility Center, remembered his patients, and expressed surprise to learn of the two long-lost embryos. “Yikes,” he said. “I feel so terribly for this couple.”

Dr. Keefe said that he would have only known if embryos were missing if someone from the lab had notified him, and in this case they had not. In the rare instances when embryos are lost or misplaced, he added, the protocol is to notify the patient immediately, apologize and explain in detail what might have happened. “Transparency is the foundation of trust and the essential element of the doctor-patient relationship,” he said.

“These are not two cans of peaches on the shelf at a Stop & Shop,” he went on, speaking of the embryos. “They are much more like two kids on a playground. When you’re responsible for them and they’re lost, you notify the people who care about them the most and tell them all you can.”

Dr. Meyer, who has devoted a career to speaking up for patients and more recently to studying and writing about bioethics, scoffs at the idea that she would have quietly accepted the news in 2000 that her embryos had been lost. “There is no way on God’s green earth,” she said.

Dr. Alvero, now the director of reproductive endocrinology and infertility at the Lucile Packard Children’s Hospital at Stanford University and the president of the Society for Reproductive Endocrinology and Infertility, referred questions to the public relations department of Women & Infants. The hospital’s spokeswoman said Dr. Frishman and Mr. Hackett were not available for comment.

‘My Line in the Sand’

At the meeting in December 2017, Dr. Prizant and Dr. Meyer said, Dr. Alvero asked what might help them feel resolved about the situation.

The couple said they wanted to find something meaningful to come from the careless treatment of their embryos. Perhaps it could provide a learning opportunity, they suggested — proposing, among other ideas, that Dr. Meyer could help train fertility staff at the hospital to interact more compassionately with and informatively to patients in the thicket of family planning.

Dr. Alvero and Mr. Hackett said they would consult with the hospital administration and get back in touch after the holidays. But by May 2018, after five months of silence, Dr. Meyer and Dr. Prizant wrote a letter to Dr. Alvero, copying the hospital’s interim president and chief executive, the Rhode Island attorney general and the head of the state’s department of health.

“As parents who cherished children, we would NOT have forgotten that our embryos were missing,” they wrote. “We would not have rested until they were found and cared for.”

Soon after mailing the letter, they got a phone call from Katherine Wills, the hospital’s director of risk management. “‘This happened a long time ago,’” Dr. Meyer recalled Ms. Wills telling her. Ms. Meyer felt the message was, “Get over it.”

Dr. Meyer explained to Ms. Wills that embryos discovered in the bottom of the tank represented to her and her husband potential human beings: children, her and her husband’s children. “I was horrified,” Dr. Meyer said.

That conversation, she said, “was my line in the sand.” Hesitant at first, Dr. Meyer and her husband decided to take legal action. “As a woman who had suffered miscarriages and infertility, all the powerful feelings of sadness, shame and grief came crashing back and the knot in my stomach was real.”

They are seeking a jury trial and punitive, compensatory, consequential damages. But Dr. Meyer and Dr. Prizant said the real point of the lawsuit is to compel the hospital, and perhaps other infertility treatment providers, to commit to reliable and accountable storage management and patient care practices. (They want to urge vigilance on the increasing number of people freezing eggs and embryos.)

In a legal filing, the hospital alleged that Dr. Meyer and Dr. Prizant “were guilty of comparative negligence” but provided no further detail. Angela L. Carr, the hospital’s lawyer, declined to comment.

“I would not be true to myself if I let this be swept under the rug,” Dr. Meyer said. “It is our job as parents to give our children, and in this case embryos, every opportunity for life and for dignity. We were denied our right to fulfill our role as parents.”

‘You Assume There is Oversight’

Dr. Prizant and Dr. Meyer’s saga is “an interesting story not because it’s unique but because it’s probably not unique,” said Jeffrey Kahn, the director of the Berman Institute of Bioethics at Johns Hopkins University. (He does not know the couple and is not involved in their case.) “There is so little regulation and no accounting of how many embryos there are in storage,” he said.

The fertility industry is a lucrative business but operates largely unchecked by regulators, Dr. Kahn said, for several reasons, including federal policies in place since the mid-1980s. The policies bars federal dollars from being used for research that involves the harm or destruction of human embryos.

Federal regulation tends to follow federal funding, often leaving privately funded I.V.F. facilities without oversight. Also, most of what takes place in an I.V.F. laboratory falls outside the purview of the Food and Drug Administration. “You assume there is oversight, as there is with most doctors and procedures, but when it comes to infertility, that turns out not to be true,” he said.

A study published in 2020 in the journal Fertility & Sterility found that 133 lawsuits were filed in the previous decade over lost, discarded or damaged frozen embryos. That number reflects lawsuits filed, which is likely a fraction of actual occurrences, said Dov Fox, the director of the Center for Health Law Policy and Bioethics at University of San Diego and one of the study’s authors. Dr. Fox also noted that most of these types of suits settled out of court, with undisclosed terms and nondisclosure agreements, making it difficult to know the outcomes.

Three lawsuits have been filed against Women & Infants Hospital related to lost embryos, including two in the mid-1990s, when Ms. Meyer was a patient. In 2019, a woman named Marisa Cloutier-Bristol described receiving in 2017 a bill from Women & Infants similar to the ones that Dr. Meyer and Dr. Prizant received, which notified Ms. Cloutier-Bristol that the hospital had a frozen embryo belonging to her and her late husband, despite having been told in 2003 that her I.V.F. cycle had not produced any viable embryos.

“I felt like I was now grieving a child I didn’t even know existed, a child I could have had,” she told “Good Morning America” in 2019. She sued the hospital. (The case has since been dismissed. Through her lawyer, Ms. Cloutier-Bristol declined to comment.)

As Dr. Meyer and Dr. Prizant’s case winds its way through the pandemic-delayed civil courts system, the couple is also thinking about what to do with their embryos.

After seeking spiritual support and guidance at their temple and their Quaker meeting, the couple is leaning toward repossessing their embryos, and burying them in the backyard in Cranston, where her mother’s ashes, and the remains of the family dog, are buried. They also have talked to a rabbi about a cemetery burial.

“We need to allow our embryos to finally have some peace and rest,” Dr. Meyer said. “And we need to find some peace and rest ourselves.”