A new study has raised concerns about ICSI (intracytoplasmic sperm injection). Presented at a symposium at the Monash Institute of Reproduction in Melbourne, Australia, the research links the use of the fertility technique by men who have genetic defects (which may have caused them to be infertile) and rare problems, such as 'ambiguous genitalia', in children born from the technique.
About five per cent of men who need to use the ICSI technique might have discrepancies on their Y chromosome called microdeletions. In such cases, the genetic defects will be passed on to any male offspring, as will any genetic cause of his infertility. A small proportion of ICSI babies have been born with minor genital malformations.
The latest research, carried out at the Pasteur Institute in Paris, looked at a number of cells from men who had microdeletions on their Y chromosomes. The researchers found that the entire chromosome was missing from some other body cells, and have suggested that this may mean there is some wider genetic instability. Widespread loss of the Y chromosome from cells could have serious consequences as the chromosome governs the formation and development of sexual organs.
Sometimes, the result of the loss of the Y chromosome from some of a baby's cells is 'genetic mosaicism', which may cause such conditions as ambiguous genitalia. But the researchers say that these kinds of conditions are apparent at birth and would have been detected in larger studies of ICSI babies. Apart from a small increase in hypospadias, there is no sign that malformations are generally increasing. Dr Ken McElreavey, who led the Pasteur Institute team suggested, however, that fertility doctors performing ICSI should look out for men who have Y chromosome deletions.