Research suggests male fertility treatment may alter embryos

A highly magnified image of an egg being injected with a single sperm during the ICSI procedure

March 30, 1999
Web posted at: 11:43 a.m. EST (1643 GMT)

ATLANTA (CNN) -- A breakthrough treatment for male infertility may cause abnormalities in fertilized eggs, researchers say in the April issue of the journal Nature Medicine.

Intracytoplasmic sperm injection -- ICSI -- was introduced in 1993 to help men with low sperm counts become fathers. The technique involves injecting a single sperm into an egg.

Researchers who studied a small group of rhesus monkeys treated through ICSI found that two proteins normally stripped from the sperm during fertilization remain attached following the procedure. The presence of the proteins cause an unusual interaction between the sperm and egg.

But Dr. Gerald Schatten and his colleagues at the Oregon Health Sciences University in Portland said they found no evidence that the alteration causes problems with babies born from the technique. Most abnormalities that occur after ICSI are probably due to defective DNA from the father rather than the technique itself, Schatten said.

The study gave the first indication that the procedure itself causes some damage. But Schatten said doctors should continue to use the technique, and couples considering it should not be concerned.

"I'm the first to say this is a miraculous technique," Schatten told The New York Times. "I can't see going to someone who would say, 'Yeah, I can give you a kid, but I want another 35 years of research before I'm going to touch this.'"

Besides, Schatten said, any severe chromosomal defects are likely to end a pregnancy naturally.

Debbie and Tony Lee say the birth of their daughter Chloe outweighed the risks of ICSI

Schatten's study isn't the first time ICSI's safety has been called into question. An earlier Australian study of 1-year-olds suggested that children born from ICSI fertilization may develop slower than children conceived naturally or from routine methods of in vitro fertilization. But a Belgian study of 2-year-olds showed no evidence of slower development.

New parents Debbie and Tony Lee said they aren't overly concerned with the risks. After six years of trying, they finally conceived Chloe, now 3 1/2 months old, via ICSI. They say they would use the procedure again.

"I knew there were risks," said Debbie Lee. "I read the consent forms and read all the articles about it, and so I pretty much knew there were a lot of risks involved. But they seemed small."