In order for pregnancy to occur, an egg has to be released from the ovary and unite with a sperm. Normally this union, called fertilization, occurs within the fallopian tube, which joins the uterus (womb) to the ovary. However, in IVF the union occurs in a laboratory after eggs and sperm have been collected. Embryos are then transferred to the uterus to continue growth.Candidates
There are five major steps in the IVF and embryo transfer sequence:
To control the timing of egg ripening and to increase the chance of collecting substantial number of eggs, fertility drugs are prescribed according to each individual case. Before dertemining the egg retreival schedule, we perform an ultrasound of the ovaries to check the development of eggs and a blood/urine test to measure hormone levels.The Egg Retrieval Process
The retrieval procedure to obtain the eggs is performed trans-vaginally using a hollow needle guided by the ultrasound image (this is completely comfortable under adequate sedation and local anesthesia). Eggs are gently removed from the ovaries using the needle. This is called "follicular aspiration." Its timing is crucial because the egg will not develop properly if it is collected too early; if too late, the egg also may develop poorly or may have already been released from the ovary and lost.
The eggs are immediately identified by our embryologists in our special IVF laboratory. They are placed with the sperm in incubators to allow fertilization to take place. The eggs are examined carefully at intervals to ensure that fertilization and cell division have taken place; the fertilized eggs are now called embryos.
Embryos are usually placed in the wife's uterus 2 or 3 days after egg retrieval. A speculum is inserted into the vagina to expose the neck of the womb (cervix). The embryos are suspended in a tiny drop of fluid and then very gently introduced through a catheter into the womb, often under ultrasound guidance. The transfer is followed by a resting period, blood tests and possibly ultrasound examinations to verify if pregnancy has been established.To summarize, the IVF procedure consists of: