Marie Valdes-Dapena, 91, pathologist

The photograph shows Dr. Marie Valdés-Dapena performing an autopsy. She is nine months pregnant. She is watching a clock - timing her contractions, determined to complete the job before delivering her own baby.

In that picture, vividly recalled by her daughter Cris, are hints of an extraordinary life to come: a pioneer in the study of Sudden Infant Death Syndrome; a leading pediatric pathologist who was among the first to recognize what is now known as child abuse; and a working mother of 11 children in an era when few women worked and far fewer were doctors.

Dr. Valdés-Dapena, 91, who was best known to the public as a pathologist in the biggest maternal infanticide case in recorded history - Marie Noe's murder of eight babies in Kensington - died Sunday at the Rose Tree Place retirement community near Media. She had struggled with advanced dementia for many years, the family said.

"She was warm as toast and never ever ever too busy to devote what seemed like all the time in the world to the lowliest, us residents," said Sarah Long, who arrived at St. Christopher's Hospital for Children as a resident in 1970 and has been chief of infectious diseases for 35 years.

"She was a character of her time," Long said, with owlish glasses that would "fall down her nose as she was doing an autopsy. She would push them back with a great big smile and tell you something she had just noticed."

And then, if it was a Saturday morning, when her husband slept late, she would drive her VW bug home to serve him breakfast in bed.

In 1944, when Dr. Valdés-Dapena graduated from Temple University School of Medicine, "pathology was the top of the medical profession," said M. Daria Haust, a professor emeritus at the University of Western Ontario; pathology is the science of disease, and pathologists provided the answers.

The two women and a third colleague were constant roommates at conferences in the fledgling field of pediatric pathology. They were known as "The Three Graces," Haust said, "because we were ladies, you see."

St. Chris, at the time Temple's teaching hospital for children, was on equal footing with Children's Hospital of Philadelphia - except in pathology, where St. Chris, was an international leader.

Waldo E. Nelson, author of the leading pediatrics textbook for 40 years, was pediatrics chair at Temple and medical director at St. Chris. He hired James B. Arey, one of the first pediatric pathologists. Overworked, Arey hired Dr. Valdés-Dapena in 1959 from Women's Medical College Hospital (now Drexel University College of Medicine and Hahnemann University Hospital).

Hardly anything was known about baby post-mortems.

"Most of the methodology I invented myself," Dr. Valdés-Dapena said in a 1999 interview. Seeking more experience with infants, she moonlighted one afternoon a week at the newly professionalized Philadelphia Medical Examiner's Office, itself gaining a national reputation under Joseph Spelman.

That's where she first encountered "crib deaths": babies that went to sleep healthy and were dead in the morning, with no clues on autopsy. She had investigators visit the homes looking for clues, and then put pins on a big map to find patterns, said Joseph McGillen, a retired investigator in the ME's office.

They didn't find a culprit but it was one of the earliest scientific examinations of what later became known as Sudden Infant Death Syndrome. In the 1960s and '70s, Dr. Valdés-Dapena was a leading researcher and the chief debunker of various SIDS theories, from viruses to milk allergies. Many such deaths are still unexplained, but after recommendations in the 1990s that babies be placed on their backs to sleep, mortality plummetted from about 20,000 a year to under 5,000.

One that she got wrong - and later apologized for - was the theory, popular for a while, that sleep apnea caused SIDS and baby monitors could prevent it.

Another was Marie Noe.

Between 1949 and 1968, eight of Art and Marie Noe's babies died mysteriously at home. (A ninth was stillborn, and a 10th died in a hospital six hours after birth.) Among Dr. Valdés-Dapena's first autopsies for the city, in 1958, was Constance Noe, baby No. 5, and she observed or assisted on all the Noe cases after that.

While it may seem obvious today, the idea that a mother could kill her child was alien then, perhaps moreso for someone raising 11 children. "I remember hearing her saying a mother could not do that," said Dr. Valdés-Dapena's eldest child, Victoria Pendragon. Indeed, a Life magazine story after the sixth unexplained death drew widespread sympathy for the Noes.

While there was no proof of murder, however - primitive forensics could not distinguish accidental crib death from intentional suffocation - suspicions ran high within the medical examiner's office. And 30 years after the last Noe death, a book about SIDS, The Death of Innocents, briefly quoted Dr. Valdés-Dapena saying that investigators believed "it was likely a case of multiple murder."

The book prompted Stephen Fried to look back at the case. His investigative reporting for Philadelphia Magazine in 1998 led the police to reopen it. Noe confessed and was sentenced to house arrest; she remains on probation at age 84.

Dr. Valdés-Dapena was already experiencing the first signs of dementia when, now convinced of the murders, she helped close the case.

"Her learning curve formed the world's learning curve," said Fried, who calls her "heroic."

Born Marie Agnes Brown on July 14, 1921, in Pottsville, she quickly became Molly, claiming to despise her given name; colleagues later called her "Dr. Molly." Summering in Ocean City, N.J., she became friends with her neighbor Grace Kelly.

She wanted to be librarian. Her father wanted all his children to be doctors.

"I said: 'Daddy, I couldn't do that. When you go to medical school they make you go and look at dead bodies, but I couldn't do that. I'd drop over in a faint,' " she recalled in the 1999 interview at a meeting of the Society for Pediatric Pathology, which she had earlier served as president.

When she graduated from Immaculata College, however, her father took her to Temple and she was admitted to medical school. (Neither Jefferson nor the University of Pennsylvania took women, she said.)

After delivering a baby one night as an intern at Philadelphia General Hospital, "a tall, dark, and handsome Cuban chap came over" in the doctors' dining room. She soon married pathologist Antonio Maria Juan Hedwiges Valdés-Dapena Y'Galtes, the son of a prominent physician who had grown up with servants - for each child - in Havana.

It was understood that she would give up her career if he asked, but he never did. She served as his pit crew when he raced his silver Porsche.

"Ours has been and is a love affair," she said in 1970.

They raised their children in The Castle, a stone mansion in Wallingford. Pathology was everywhere. "There were home movies of autopsies," said son Peter, and "occasionally body parts in the fridge."

In 1976, her husband announced a move to Florida - with his mistress, it turned out. His wife came anyway, but Antonio soon divorced her; he died in 1992. She spent most of the next 21 years teaching at the University of Miami School of Medicine and practicing at Jackson Memorial Hospital. She retired in 1996 and returned to the Philadelphia area.

A practicing Catholic, she attended Mass daily and sang in church choirs for much of her life; she also recorded books for the blind (and wrote or coauthored six of her own).

Although known for her work with SIDS, she had a broader impact.

"She fought for mothers to be able to hold their child," letting them grieve, said her daughter Cris.

And she was ahead of most in the field at recognizing the signs of battered children and speaking out about child abuse, said Stephen Ludwig, a pediatrician at Children's Hospital of Philadelphia, who set up some of the first child abuse teams in hospitals as the modern child-protection system emerged.

"For I don't know how long I thought to myself that she wasn't a mother first, she was a doctor first. But as a mother in retrospect she must be remarkable," said her daughter Victoria. "Eleven children, and all kind of awesome."

Besides Victoria, of Paw Paw, W. Va.; Cris, of Bermuda; and Peter, of New York City, she is survived by children Debi, of Los Angeles; Andres, of Hanover, Pa.; Carlos, of Vienna, Va.; Mark, of Toledo, Ohio; Antonio, of Spotsylvania, Va.; Dan, of Media; Patty Fater, of Cape Cod, Mass., and Cate, of Kennett Square; 21 grandchildren, and five great grandchildren.

No funeral is planned. Arrangements for a memorial service are incomplete.