A baby boy was born Monday to a 20-year-old Baltimore woman minutes after she had died from gunshot wounds, in a rare medical drama played out under bright lights in an otherwise drab city hospital emergency room.

The infant, an orphan at birth, died at 4 p.m. yesterday at Baltimore City Hospitals, where he was delivered 21 hours earlier by a 27-year-old resident obstetrician in an emergency cesarean section performed in 12 seconds. The child's mother -- seven months pregnant -- had been declared dead on arrival at the hospital in what police said was an apparent murder-suicide. The father, police said, shot the woman and then himself.

Medical experts described such a birth after death as a highly unusual occurrence when the difference between life and death for the newborn is a critical matter of minutes. The difficulties inherent in such cases were evident in this instance, where doctors and nurses could stretch the limits of medicine only so far and no further.

"Normally, you have four to eight minutes," said Dr. Warren Pearse, executive director of the American College of Obstetricians and Gynecologists, "and after four minutes, you could have a damaged baby from lack of oxygen." Pearse said no statistics are available on the number of such births, but he guessed that maybe 50 occur each year in the United States.

The Baltimore drama took little more than a half-hour to unfold from its tragic inception to its penultimate climax. The exact time of the mother's death is uncertain, but, according to official accounts, between five and nine minutes elapsed between the pronouncement of her death and the birth of her child.

It began shortly before 6 p.m. Monday in a northeast Baltimore apartment, where, police said, Steven Keith Jones Sr., 20, allegedly fired four shots from a .25-caliber handgun into the head and one shot into the hip of Sharon Joseph, 20. A neighbor who heard them quarreling and saw Jones running down the apartment steps found Joseph, a prelaw student at Morgan State University, lying on the floor of her apartment, unconscious and bleeding from the head. On a bed nearby lay their year-old son, Steven Jr.

Baltimore police logged the neighbor's call for help at 5:57 p.m. and the officer's arrival three minutes later. The Fire Department ambulance arrived at the apartment at 6:04 p.m., and 14 minutes later the white and orange vehicle, sirens blaring, was on its way to the brick-exterior hospital in east Baltimore. During the three-mile ride, Len Weber, the paramedic, tried to revive Joseph.

The Medic Unit 13 ambulance arrived at the municipal hospital at 6:25 p.m., pulling up to the ramp adjoining the emergency-room complex. The woman was rushed inside and into the first room on the left. The doctors call it the trauma room, a 20-by-30 foot chamber with beige walls and fluorescent lights.

"We can handle everything there," said Dr. Gustav C. Voigt, emergency department director. "But, normally, there are no deliveries in the trauma room. I go back 20-plus years, and I can recall in the crevice of my mind only one, a C-section [cesarean section] on a woman who was pregnant and was killed."

"Normally, if there is any chance of having a live patient, you postpone a C-section," said Dr. Robert G. Castadot, head of obstetrics at the hospital. "In a long-lasting illness, the fetus usually dies before the mother, because it is sensitive to the abnormality. The chance of survival for a fetus is best when the death of the mother is a sudden one, like an accident or a shooting."

On this occasion, the death was violent and sudden, and the hospital had 10 minutes, from the time it was notified until the woman's arrival, to prepare. Dr. Marian Damewood, 27, a graduate of Wellesley College and Johns Hopkins University Medical School, was in charge. In her young career, she had performed some 150 cesareans, but none like this. i

Midway through her 36-hour shift, she directed the delivery suite staff to bring the appropriate equipment, including a fetal heart monitor, to the first floor room. The atmosphere, she said, was "very controlled. Everyone was in place and ready for the patient to arrive."

There were 15 altogether, doctors and nurses and technicians, when the patient arrived. Even as efforts to revive the mother continued with a "cardiac paddle" used to shock the heart back to life, Damewood and her crew placed the fetal heart monitor on the mother's stomach. The monitor measured 60 to 70 heart beats per minute. Normal is 120 to 160. This was, she said, a "baby in distress."

Dr. Nicholas Shorter, assistant resident in surgery, declared Sharon Joseph dead in the trauma room. By then, it was almost 6:30 p.m. The exact time is uncertain. There were other things to do.

Dr. David Ginsburg, a senior resident assisting Damewood, made the incision, a vertical cut reserved for emergencies, exposing enough to ease the actual delivery. Together, Damewood and Ginsburg retracted the tissues, spreading them apart to reveal the fetus. Twelve seconds after the incision, Damewood lifted the baby out of its mother. He weighed 1,639 grams, Damewood noted, about 3 pounds, 9 ounces.

A pediatrician was standing by to rush the newborn to the intensive-care nursery, where he was placed on a respirator. Damewood did the paperwork, then went about her business, returning to the delivery room, she said, to see if there were any [other] problems."

Damewood had been "thankful the baby was alive and hopeful for its continued care and survival," she said. But the baby suffered seizures and low blood pressure, developing what Dr. Dennis Heading, the attending physician, called "severe lung disease and respiratory distress syndrome," resulting in part from lack of oxygen.

The moments between the mother's death and the baby's birth had been too many. "I can't think of a more inopportune manner of being born," Heading said.