With an announcement that is already producing applause and hand-wringing, doctors at a fertility center near Washington will report today that they can substantially stack the odds that a couple can have a baby of the sex they choose.
The method, developed by the Genetics & IVF Institute in Fairfax, Va., involves sorting sperm by the amount of DNA they contain and then using them for artificial insemination.
It capitalizes on the fact that there is only one difference between sperm that carry the Y chromosome, which produces males, and those with an X-chromosome, which produces females: Sperm with a Y chromosome have about 2.8 percent less genetic material.
The investigators report that if they select for X-bearing sperm, they end up with sperm samples in which 85 percent of the cells have an X-chromosome. If they select for Y-bearing sperm, the result is a sperm sample in which 65 percent of the cells contain a Y-chromosome.
In a paper being published today in the journal Human Reproduction, the investigators, led by Dr. Edward Fugger, report results for couples who wanted girls. Of 14 pregnancies that progressed far enough for doctors to determine the fetus' sex, 13 had only female fetuses. Ten out of the 11 babies that were born so far were girls.
Fugger said that the group has produced about the same number of pregnancies for couples who wanted boys and that the results are consistent with what the sperm sorting would predict. But, he said, the investigators are not releasing the results of those pregnancies until they are published in a medical journal.
The Genetics & IVF Institute, a private, for-profit medical center, is a leader in fertility research and prides itself in being among the first to offer new reproductive techniques.
Pub Date: 9/09/98