IUI is a simple treatment which can be undertaken by any trained gynaecologist, not necessarily a fertility specialist. Because it is widely available and relatively affordable, IUI is the first line of therapy after tablets such as Clomiphene have failed. The only drawback of IUI however, is its low success rate. You can generally expect a pregnancy rate of between 10 and 15% depending on your age, the medications used and the number of mature eggs at the time of IUI.
Because of this low pregnancy rate, doctors usually recommend that IUI needs to be repeated a number of times. There is no consensus on how many times you should do IUI before accepting that it is not working for you. However, the generally accepted figure is approximately three attempts.
The low success rate of IUI is due mainly to the many unknown factors inherent in this treatment. For example we have no idea if the eggs have been picked up by the fallopian tube, if the tube is functioning normally to transport the eggs down to the uterus and whether the sperm is actually fertilizing the eggs and embryos being created.
It is for this reason that after two to three failed attempts at IUI, it is recommended that the next course of treatment is IVF.