What is believed to be the first frozen-embryo baby in Maryland has been born to a Baltimore couple involved in a test-tube baby program.
The healthy baby girl, who weighed 5 pounds, 11 ounces at birth, is the first child of the couple, who have asked that their names not be used. She was conceived at the in vitro fertilization program at the University of Maryland Medical Center and delivered Nov. 8 at Union Memorial Hospital.
She joins a small but growing group of infants in the world whose birth is the result of a combination of two techniques -- the 12-year-old in vitro fertilization technology and its newest innovation -- freezing embryos, or cryopreservation.
More than 140 frozen embryo babies have been born at centers in the United States since 1986, about 40 of them at Jones Institute for Reproductive Medicine in Norfolk, Va., said Dr. Howard Jones, director and former Johns Hopkins Hospital faculty member. The world's first frozen embryo baby was born in Australia in 1984.
During the in vitro fertilization process, infertile women take hormones to stimulate production of eggs. The eggs are removed from a potential mother and united in a laboratory petri dish with the father's sperm.
Normally, fertilized eggs, or embryos, are placed back into the mother's uterus within a day or two after they are retrieved. AT UM's Assisted Reproductive Technology Program, four or five eggs usually are implanted and any leftover eggs are frozen.
But, in the Baltimore mother's case, the return of the embryos was delayed because she had a high level of estrogen in her bloodstream.
"She was at risk for ovarian hyperstimulation syndrome, a condition which can be very harmful and even lead to death," said Dr. Howard D. McClamrock, an obstetrician who was her fertility doctor.
The embryos were frozen for three months, then thawed and implanted.
When freezing an embryo, which researchers agree requires much patience and skill, the temperature is lowered gradually over 2 1/2 hours to minus 321 degrees Fahrenheit. The frozen embryos are stored in a glass tube and then placed in liquid nitrogen. Cryopreservation involves a computerized process with equipment that costs about $30,000, McClamrock said.
For many infertile women, the freezing process is becoming a more common part of in vitro fertilization, he said.
"Embryo freezing allows a woman to avoid further procedures to stimulate and retrieve eggs if pregnancy does not occur on the first try at implantation," McClamrock said, and ". . . it cuts down dramatically on the cost, saving about $2,200 in hospital and physician fees for each retrieval procedure that does not have to be performed."
In Maryland, the cryopreservation technique also is being used by Greater Baltimore Medical Center, Johns Hopkins Hospital and an independent group of fertility specialists in Rockville. So far, none has reported a birth, said McClamrock, who said he personally has checked the status of their programs.
"We really don't know how long these embryos can be kept frozen," he said. "That hasn't been studied. We know that very little changes happen to these embryos that are frozen, the same with sperm. You probably could keep them frozen at this extremely cold temperature in excess of a hundred years."
That embryos can survive unharmed in this frozen state for more than 100 years raises ethical and legal questions, said Jones. Those include: How many embryos should each couple be allowed to store? If a couple moves away, adopts a child, divorces or dies, what should be done with unused embryos? Can an embryo be adopted? At what point does the embryo achieve a legal standing of its own?
Seventy to 80 percent of the frozen embryos survive the freezing, McClamrock said. "If these very early embryos have a problem, they don't grow, they die," he said. "And that probably is the reason why we have no birth defects when we use this new technology."
The UM program freezes its embryos when the cell has not divided and the male and female genes have not intermingled, he said. "Some people feel that if the genes haven't mixed, then the embryo is not a person yet," he said. "It's the most widely used method and we feel the embryo is a little more stable in the one-cell stage."