IVF and ICSI are the more sophisticated treatment options for the couples suffering with sub fertility. In both methods the ovum(egg) and the sperm taken out of the body and fertilization occurs out side of the body.
IVF is an abbreviation of In Vitro Fertilization. In laymen term this is the TEST TUBE baby. However the fertilization usually occurs in a petri dish which is a round glassware with wide mouth than a test tube. The ovary which produces ovum (egg) is stimulated with drugs to produce multiple eggs (usually in a cycle only one egg is released by the ovum). The matured eggs are sucked out of the ovary by special needles. As this method is high cost procedure, to avoid the failure, multiple eggs are used at a time. The eggs are placed in a petri disk and the sperm which is from the semen is also placed in to the same disk. The meeting of the egg and sperm and fusion of the nucleus occurs naturally with out any intervention. The fertilized ovums are kept in a disk till it grow optimally (usually 2or 3 days). The selected embryos will be transferred to the uterus by special equipments. Then the pregnancy continues as a normal pregnancy.
ICSI is an abbreviation of Intra Cytoplasmic Sperm Injection. In this method, the egg and sperm are taken out of the body. The sperm is injected in to the egg via special needle. (In IVF, egg and sperm join together and produces embryo by nature). The fertilization is more successful in this method. However the pregnancy success rate may depends on the acceptance of the embryo by the uterus.
In both IVF and ICSI, the donor sperm can be used if the male partner cannot produce enough sperms with standard quality. However there are lot of ethical issues in getting donor sperms.
Both IVF and ICSI are useful artificial methods of making a woman get pergnant.
In both methods, the fertilization occur outside the body.
Both are expensive procedure, however the ICSI costs more.
The donor sperm and surrogate mother can be used to get sperm and egg, however the ethical considerations will restrict the usage of those.