"They are in no way out of the woods," said neonatologist Gerard Cleary.
Babies born this early typically spend 10 to 12 weeks in the hospital. They have a 10 percent chance of death and a 15 percent risk of significant disability. Multiplied across all the babies, he said, "the risks for this family are extraordinarily high."
In a short presentation devoted mostly to thanking hospital personnel for their efforts, Stacey Carey, who had undergone fertility treatments, said she was "very, very surprised" to learn she was pregnant with six.
"We also have a 16-month-old daughter, so our family of nine is now complete," she said to chuckles from the crowd of hospital staff, reporters and photographers.
Carey said the couple has not thought out all the logistics of caring for the babies, but have a "strong support system."
Stacey Carey, 33, is a teacher in the Centennial School District. Brendan Carey, who did not speak during the news conference, is 41, and works as a bartender at SugarHouse Casino. They live in a four-bedroom house and have one car, a four-passenger SUV.
Sextuplets are quite rare. Of the 4.2 million births in the United states in 2008, only 46 were quintuplets or larger groups of multiples, according to the U.S. Department of Health and Human Services.
Stephen J. Smith, an Abington perinatologist, said Stacey Carey underwent a fertility treatment called ovulation induction.
Samantha Pfeifer, a fertility expert at the University of Pennsylvania, said ovulation induction uses hormones to stimulate the production of eggs. These are then fertilized with sperm, usually through artificial insemination in the uterus. This contrasts with in vitro fertilization, which involves implanting embryos. The number of babies produced is much easier to control with in vitro fertilization, Pfeifer said.
Induction costs $2,000 to $3,000 per cycle, compared to $12,000 to $16,000 for IVF. Insurance typically doesn't cover fertility treatments in Pennsylvania, she said.
Pfeifer, who chairs the practice committee for the American Society for Reproductive Medicine, said that group is trying to reduce the number of multiple births created by fertility treatments because of the extra risks they create. "It's not good for the parents. It's not good for the children. It's not good for society," she said of multiple births.
While doctors have an idea of how many eggs are forming with induction, they have no idea how many will become fetuses. If a woman has not had a successful pregnancy in the past with a cycle that produced three or four eggs, they may think it's OK to fertilize large numbers of eggs. "In the best of circumstances, you can be surprised," Pfeifer said.
Julianna, the Careys' older child, also was conceived with the help of fertility treatments.
If there are too many babies after induction, Pfeifer said, parents can selectively abort some of them at 12 weeks, but that's "extremely hard" to do emotionally.
Smith said the primary risk of pregnancies with multiples is preterm births. A normal pregnancy lasts 37 to 40 weeks. Twins typically are born at 35 1/2 weeks. Most sextuplets are born at 26 to 28 weeks.
Carey spent the last six weeks of her pregnancy in the hospital and went into labor at 27 1/2 weeks.
The hospital had been preparing for the births for weeks. It had teams of physicians, nurses and respiratory therapists ready for each baby. Smith did a caesarian section and handed the babies - labeled A through F - to their corresponding teams. To be sure not to mix the babies up, the staff wrote their letters on the soles of their feet.
Smith was told to wait 30 seconds to a minute between babies. "They told me to recite the alphabet," Smith said.
It all took six to eight minutes.
Contact staff writer Stacey Burling at 215-854-4944 or sburling@phillynews.com.Follow the Inquirer at www.Twitter.com/PhillyInquirer and www.Facebook.com/PhillyInquirer