In-vitro fertilisation (IVF)
IVF is probably the most well known of the "Assisted Reproductive Technologies". It is otherwise known as "test tube baby", and has helped infertile couples conceive and bear children for over two decades. These days, fertilization actually occurs in a dish, and not a test tube. It was originally developed to help couples overcome tubal factor infertility, but has become useful in treating other factors, such as immunological problems, unexplained infertility and male factor infertility.
IVF is basically a four step process

First, you take medications to make multiple follicles begin to develop on your ovaries. This step is referred to as ovarian stimulation, or superovulation.
Step two involves monitoring follicular growth by ultrasound, to determine egg growth and uterine lining development. When it is determined that the follicles and the uterine lining are appropriately mature, a final maturation trigger shot of Human Chorionic Gonadotropin is then administered.
36 hours after the final maturation trigger shot

The third step begins with retrieval of the eggs by ultrasound-guided-needle aspiration, this process is best done under light anaesthesia. A sperm specimen is then washed and prepared for insemination. The washed sperm is then placed in a dish with the eggs, and they are placed in an incubator for 18 hours. After 18 hours, the incubated eggs are observed for normal fertilization ( penetration of the ovum by the spermatozoa and fusion of their respective genetic materials) , under a microscope, where the pronucleus of egg and sperm can be seen. The fertilized eggs (zygote) are then incubated for further development into multi-cell (6to8) embryos and/or blastocyst.

The fourth and final step involves transferring the embryos or blasocyst into the uterine cavity via a catheter inserted through the cervix. The number returned varies with the desires of the patient, under the guidelines of age categories; under 40 years old, up to two embryos; 40 years and older, up to a maximum of three embryos. Additional embryos and/or blastocyst may be frozen and stored for future use.