I feel sorry to hear your not so good past experiences with Iui treatment cycles..the reason of infertility can be anything but what matters is the end result and it can be very disappointing when things don't go the way expect.
IVF is a process by which egg cells are fertilised by sperm outside the human body. Hormonal injections are given to the patient to increase the productivity of the eggs. The eggs are removed from the ovaries and fertilised with sperm of the partner within a controlled cultured environment. The fertilised egg is then transferred to the patient’s uterus with the aim of establishing a successful pregnancy.