Belgian scientists have invented a new treatment for male infertility that they say may allow virtually any man, no matter how few or misshapen or immobile his sperm cells, to father a child.
The method, developed by Dr. Andre C. Van Steirteghem of the Brussels Free University in Belgium, involves the direct injection of a single human sperm into a human egg in a petri dish.
Scientists had thought such a technique would never work, because it bypasses the complex chemical reactions that take place when the membrane of a sperm meets the membrane of an egg, and because no one, including Dr. Van Steirteghem, has succeeded in fertilizing animal eggs by directly injecting sperm.
In a telephone interview, Dr. Van Steirteghem reported that, in the last year, he had successfully fertilized 65 percent of the eggs he injected. A third of the women who have received the embryos grown from the fertilized eggs have become pregnant, he added.
So far 300 pregnancies have been produced through sperm injection, and 100 babies born. Most of the rest are continuing pregnancies.
The new technique's astonishing success is expected to create an entire industry for in vitro fertilization.
Infertility affects about 2 million American men. In about a third of them, the sperm count is so low, or the number of abnormal sperm so high, that no previous method developed to coax sperm to enter the eggs could be used successfully.