I am 40 and have been through various unsuccessful fertility treatments over the past 10 years. My husband and I have just gone through our fifth ICSI cycle. Despite my age, we have always managed to retrieve a good quantity of eggs leading to good-quality embryos. I am losing heart with each failure. Is there anything further we can look at or do, to establish why our treatment repeatedly fails?

G.W.

The reason you are not conceiving is most likely due to an irreversible factor: your age. Age-related issues occur regardless of the numbers of eggs you produce. Age is probably the biggest factor in failure of IVF, even given the presence of good-quality embryos. Obviously, if you produced no eggs or if you had low estrogen levels, your results would be worse. But age is a factor regardless. Failure to achieve success speaks for itself.

Too often patients focus on finding a cause for their treatment failure. Unfortunately, while this search may make you feel better, the tools we have available are rather limited. Unless there is a specific infertility factor that can be addressed directly -- such as blocked fallopian tubes, failure to ovulate or the absence of sperm -- the most cost-effective approach is to see what has worked for others with similar situations. As you have no doubt discovered, this may necessitate ovulation induction and intrauterine insemination and ultimately IVF (in vitro fertilization), sometimes with ICSI (a form of in vitro fertilization that involves injecting the sperm directly into the egg).

However, if you have undergone multiple treatment cycles and no other factors are evident, it would seem that the most likely factor is age-related infertility, which should be considered irreversible. The most effective option to correct age-related infertility is the use of donor eggs.