Hospitals began to give new mothers more private time with their infants, allow fathers into the delivery room and let young children visit their baby siblings in the hospital.
“We are bringing back an essential ingredient of birth,” Dr. Klaus told The New York Times in 1993. “This is humanizing maternal care.”
Dr. Klaus and his wife, Phyllis Klaus, were among the founders of DONA International, an organization that certifies helpers who provide emotional and physical support for mothers before, during and immediately after childbirth. The initials stand for Doulas of North America; the word doula is derived from the Greek word for servant-woman.
Dr. Klaus, his wife and Dr. Kennell, who died in 2013, said that the presence of a doula shortens labor, reduces the demand for pain relievers, decreases the number of Cesarean births and promotes an early and enduring attachment between mother and child.
Dr. Klaus and Dr. Kennell advanced their bonding theory in 1972 in The New England Journal of Medicine after exploring the behavior of goats. They noticed that when mother and baby goats were separated immediately after birth, the mother would butt away its offspring and never successfully reunite with it.
But their theory proved controversial. Some adoptive parents complained that the bonding theory diminished them, and some feminists said it placed blame on the mother if her relationship with the child became troubled later.
Others questioned the implications of describing the immediate bonding period as “critical.” Dr. Klaus later said that describing the first hours after birth that way had been a mistake.
“It’s a ‘sensitive’ period,” he said, amending the language, in an oral history interview for the American Academy of Pediatrics in 2000. “Critical means if it doesn’t occur, all is lost.”
Moreover, he said, the use of the word “suggested that bonding was like an epoxy glue rather than a slow-acting sticky substance.”
“Rather,” he said, “I’d say there is a suggestion that for some mothers additional contact in the first hours and days of life may be helpful, and in some it may have a profound effect on how they care for the baby, especially poor mothers with few social supports.”
Marshall Henry Klaus was born on June 6, 1927, in Lakewood, Ohio, near Cleveland, to Dr. Max Henry Klaus and the former Caroline Epstein, a teacher.
He graduated from Western Reserve University (now Case Western Reserve University) and its School of Medicine. While he was in medical school he developed polio, which left him with a frail right arm. He would have liked to be an internist or an obstetrician, he said later, but specialized in pediatric pulmonology and neonatal development in part because of his disability.
“I picked newborns because I could thump the chest,” he said. “I have a good hand. I can suture with this hand, but I can’t deliver babies easily. But I can take care of little babies, and that’s why I went into pediatrics.”
His first marriage, to the former Lois Krieger, ended in divorce. In addition to his daughter Laura, he is survived by his second wife, the former Phyllis Stoller; four other children from his first marriage, Susan, David, Alisa and Sarah Klaus; Phyllis Klaus’s children from an earlier marriage, John and Geoffrey Stoller; a brother, Carl Klaus; and five grandchildren.
Among the books he wrote with Ms. Klaus were “The Amazing Newborn: Discovering and Enjoying Your Baby’s Natural Abilities” (1985) and “Mothering the Mother: How a Doula Can Help You Have a Shorter, Easier, and Healthier Birth” (1993).
Dr. Klaus, with Maureen Hack, also made the film “The Amazing Newborn” (1987), which demonstrates a newborn baby’s responsiveness.