Flow Cytometric Separation
WHAT IT IS: A sperm-sorting technique, also known as MicroSort, practiced at the Genetics & IVF Institute, in Fairfax, VA.
HOW IT WORKS: Prospective parents submit a sperm sample to doctors at the clinic, who stain the sperm with a fluorescent dye. Individual sperm carry either X or Y chromosomes; since X (which determine that the baby will be a girl) have slightly more DNA than Y (which determine that the child will be male), they absorb more dye. After a machine sorts the sperm, doctors perform intrauterine insemination (injecting the desired sperm into the uterus through the cervix).
One concern among doctors wary of this technique: Though the dye used to stain the DNA is considered nontoxic, its long-term effects are still unknown.
SUCCESS RATE: This method is still considered an experimental procedure, but statistics from the ongoing clinical trial at the Genetics & IVF Institute show promise. "Ninety percent of the girls and seventy percent of the boys born are the sex their parents desired," says Susan Black, M.D., a medical geneticist at the Institute.
WHO IS ELIGIBLE: Married couples with at least one child who are interested in "balancing" their families. For families with a hereditary disease, however, the child requirement is waived. The Institute does a phone interview and asks participants to have screening tests done at a lab near their home. The procedure takes place in Virginia at the Institute. There is a waiting list of several months.
COST: $3,200 per menstrual cycle (it can take at least three tries on average).
RESOURCES: The Genetics & IVF Institute, in Fairfax, VA. Call
or go to www.microsort.net.