The six surviving septuplets born Tuesday to a California high school teacher took "a slight turn for the worse" today, a hospital official said.

Laura Johnson, a spokesman for Childrens Hospital of Orange County, said all six infants, born 12 weeks prematurely, had developed jaundice, and three had incompletely developed aortas. She said that such conditions often occur in premature babies and that doctors remained optimistic the infants could be treated.

The four boys and two girls born to Patricia Frustaci, 30, and her husband, Sam, 32, each weighed less than two pounds at birth and, like all newborns, have lost weight since, Johnson said. They are being fed intravenously, are attached to respirators to aid their breathing and are listed in critical but stable condition.

Doctors at the hospital in Orange, Calif., 30 miles southeast of Los Angeles, say they are most concerned about overcoming a lung affliction, hyaline membrane disease, which is the greatest threat to the babies' survival.

A seventh baby, a 15.5-ounce girl, was stillborn and apparently died a few days before delivery because of inadequate nutrition in the womb caused by her mother's rising blood pressure.

No more than five babies born at one time in the United States have ever survived infancy, and only six sets of sextuplets are alive in the world, according to Helen Kirk, a multiple-birth expert in Galveston, Tex. The incidence of multiple births has increased in the last 20 years because of development of fertility drugs such as Pergonal, which Frustaci was taking, and because of improved methods of saving premature infants.

Dr. Ragnar Amlie, one of the neonatologists at the adjoining St. Joseph Hospital, where the delivery took place, said newborns weighing less than two pounds usually have a 30 percent to 40 percent chance of survival, principally because their lungs have not developed enough to keep from collapsing. But Dr. Carrie C. Worcester, director of the neonatal intensive care unit at Childrens, said she thought the Frustaci infants had a "50-50" chance.

The babies' jaundice, a yellowing of the skin and eyes often associated with liver malfunction, is being treated with "photo therapy," Johnson said. This use of special lights shining on the babies' skin helps their immature livers to function.

Johnson said she did not know which three babies had incompletely developed aortas. She said that the babies were receiving drugs usually given to premature infants with such conditions, and that doctors said with proper treatment they could grow out of it.

All six infants registered normal brain scans, Johnson said, but would remain in the hospital for several months. The mother, who was unconscious during the three-minute Caesarean delivery, has been allowed to see and hold only the stillborn girl, but videotapes of the surviving babies have been played for her. They show six dark-haired infants resting on their backs in isolettes with tubes and monitors taped to their thin bodies.

Each baby was labeled at birth with a letter in order of appearance. The girls -- A and D -- weighed 1 pound, 11 ounces and 1 pound, 12 ounces, respectively. The boys -- B, C, E and F -- weighed 1 pound, 8 ounces; 1 pound, 13 ounces; 1 pound, 13 ounces; and 1 pound, 1 ounce.

The Frustacis have received promises of support from relatives, friends and members of their church, the Church of Jesus Christ of Latter-day Saints, but have also appealed for public donations. An attorney is negotiating publication rights.