Siamese twin sisters who were joined at the chest and abdomen were in good condition yesterday after surgeons at the Johns Hopkins Children's Center separated them in an operation described as brief and uncomplicated.
The 4-day-old girls, whose identities were being kept secret at their parents' request, shared only skin and muscle.
"They didn't share organs," said Jo Martin, a hospital spokeswoman.
"It was a fairly simple procedure."
The babies were delivered Monday in a scheduled Caesarean section, about a month premature.
Just two weeks ago, surgeons at Children's Hospital in Philadelphia divided twin sisters who shared a single heart and some liver tissue.
That was a more difficult and troubling operation because it meant one of the twins would instantly die.
In the Hopkins case, prenatal tests had revealed that the girls were joined at the chest and abdomen, but the surgeons were unsure how complicated the operation would be until they began the separation, Ms. Martin said.
Siamese twins are identical twins who fail to separate completely from a single fertilized egg. They occur in 1 of every 100,000 births.
Yesterday's operation marked only the third time surgeons at Hopkins have separated conjoined twins.
In 1982, Hopkins surgeons separated the Selvaggio twins, girls from Delaware who were joined at the chest, sharing skin, muscle, rib cartilage, a liver and intestinal tissue.
Those twins, who were born in Salisbury, remain in good condition, Ms. Martin said.
Five years later, surgeons at Hopkins separated the Binder twins, West German boys who were joined at the backs of their heads.
The operation left the Binder twins brain damaged.
Parents of the girls separated yesterday asked Hopkins officials to release only limited information to protect the family from a media circus like the ones that surrounded the recent operation in Philadelphia and other separations of Siamese twins.