Are there any risks to the ICSI procedure ?

Couples undergoing what is a relatively new procedure are naturally concerned to know about all of the risks involved. Certain risks are common to in vitro fertilisation and ICSI; namely, the chance of developing Ovarian HyperStimulation Syndrome and the chance of multiple pregnancy. However, while there have been nearly two million babies born following standard in vitro fertilisation treatment, the number of babies born following ICSI is probably a few hundred thousand. From assessment of these babies following ICSI, the following represents the current state of our knowledge about the possibility of abnormalities. It is an unfortunate fact that 3 in every 100 babies born naturally, i.e. not as a result of fertility treatment, are born with a major malformation. The largest studies performed to date of 3,000 pregnancies following ICSI treatment has shown that the overall percentage of ICSI babies born with an abnormality is no greater than that arising in the normal population.

Normally a child is born with forty-six chromosomes (the structures which carry the genes). Girls have two X chromosomes (46 XX) and boys have one X and one Y (46 XY). In natural conceptions, approximately one in every two hundred children has an abnormality in the number of these X or Y chromosomes, e.g. perhaps an extra X or Y chromosome, making 47 XXX or 47 XXY. It appears that with ICSI the chance of having this particular abnormality is doubled to one in a hundred children. However in half of these cases it is likely that this particular abnormality may not be a new abnormality in the baby but the abnormal chromosome may be transmitted from the father to the child. Indeed the abnormal chromosome may be the reason for the fathers’ infertility.

CRM London strongly recommends that men undergoing ICSI treatment have a chromosome test to determine in advance if they do carry an abnormal number of chromosomes themselves, which could potentially be transmitted to their offspring.

Over the past few years it has been realised that approximately 10% to 15% of men who have no sperm or very low numbers of sperm have a specific defect in one of their genes that is responsible for producing sperm (this is called the DAZ gene). It is quite possible that this gene defect will be passed on to a male child, which could result in the child also, in the future, being infertile. It is now possible to test for this gene defect and the CRM London recommends that this test be performed prior to undergoing an ICSI procedure in men with very low numbers of sperm. This will enable you to be fully informed about the risk of potential problems in your children. Couples can avail themselves of the counselling facilities to discuss the implications of these tests.

There have been reports in the medical literature that boys born as a result of ICSI have a higher risk of abnormalities of the genital tract and in particular a condition called hypospadias in which the urine is passed not through the tip of the penis but through an opening lower down the shaft. This condition would require surgical correction. The largest study to date of the 3,000 pregnancies discussed above did not show that this condition occurred more frequently in boys born as a result of ICSI compared to the normal population.

Finally some men are infertile because they have a condition called congenital bilateral absence of the vas deferens (CBAVD). These men produce sperm in the testicles but lack the tubes connecting the testicles to the penis (this is called the vas) and so no sperm are ejaculated. A high proportion of men with this condition carry the gene for cystic fibrosis. It is recommended that men with no or very few sperm have this test before proceeding to ICSI treatment.

At CRM London we can perform a male genetic ICSI profile prior to undergoing ICSI treatment. This consists of a single blood test and will include a chromosome analysis, test for abnormality of the DAZ gene and a cystic fibrosis screen. Please discuss details of this test with your doctor or IVF co-ordinator.