by Dr. Avner Hershlag
ICSI, which is a procedure where a single sperm is injected into a single egg, is a cutting-edge IVF approach demanding significant technical expertise. The discovery that this could be done in the early ‘90s has revolutionized the treatment of male infertility. Whereas before ICSI, IVF was mainly a treatment for female infertility, ICSI has made IVF equally effective for males with abnormal sperm or even no sperm at all, where sperm has to be surgically retrieved from the testes. In the pre-ICSI days, couples with severe male infertility would frequently have to resort to donor insemination, thus eliminating the possibility of the man to be the genetic parent. There are now millions of children and adults whose fathers had deficient sperm, and it is because of ICSI that they have been created.
Male infertility is complex. It is not just the sperm count that tells the story. In the pre-ICSI era, we would regularly have cases of no fertilization of eggs in IVF with seemingly normal sperm. In fact, early on, we published a study on ICSI-split in unexplained infertility. In that study, we compared two groups of patients with unexplained infertility. In one group, ICSI was not used, whereas in the other group the eggs were split: about half underwent ICSI and half insemination. What we found at that time, was that in the ICSI-split group, there were no cases of zero fertilization, while there were a few cases in the insemination-only group. Therefore, we concluded that the ICSI-split in patients without clear male infertility rescued IVF cycles from a total failure where no embryos were available to transfer, a pretty devastating end of a cycle for any IVF patient.
My explanation for this phenomenon is that there is a group of males with subtle infertility, whose sperm count looks normal according to the minimum criteria set by the World Health Organization (WHO), yet whose sperm has no capacity to fertilize eggs. ICSI allows us to bypass the sperm-egg interface and increases fertilization in select cases.
That being said, the JAMA study may point to over-use of the ICSI procedure in some couples. The problem remains: how do you distinguish between males who have normal fertilization capacity, and that much smaller group of males whose sperm test is normal but has lower fertilization potential?
In lack of a better test, IVF remains not only the most effective fertility treatment to date, but also the most powerful diagnostic test. Until IVF is performed, for patients who have never conceived before, there is no absolute certainly that the sperm will fertilize an egg. Until we have another test to prove that, patients with unexplained infertility with sperm normal by WHO criteria, will only find out if their sperm can fertilize the egg through IVF. The use of ICSI-split in unexplained infertility, where some of the eggs undergo ICSI, safeguards us against total fertilization failure. Given the physical, emotional and financial impact of an IVF cycle this is as important as the figures presented by this study, without a single embryo available to transfer.
Dr. Hershlag was asked to comment on the ICSI study, and the corresponding article and his comments can be found on news.health.com.