Prior or repeated fertilization failure with standard IVF culture and fertilization methods. Frozen sperm collected prior to cancer treatment that may be limited in number and quality. Absence of sperm secondary to blockage or abnormality of the ejaculatory ducts that allow sperm to move from the testes. ICSI is not a perfect technique. Some eggs will be damaged by the ICSI process.
Some eggs have plasma membranes that are difficult to pierce.
In other instances, the fertilized egg may fail to divide, or the embryo may arrest at an early stage of development. Egg fertilization rates of 50 percent and cleavage rates of 80 percent or more are expected, but only 15 to 20 percent of egg retrievals produce a baby in well-selected couples. Other factors such as poor egg quality and maternal age may cause these percentages to drop. Perinatal outcomes studies in Europe suggest that although multiple pregnancies are common in ICSI, there is to date no evidence of increased incidence of congenital malformations or abnormal karyotypes. There is no evidence that abnormalities may arise later in life to babies born as a result of ICSI, although there is also no guarantee that all babies will be normal.