The patient is sedated and anesthetized before the procedure. A needle guided under ultrasound is inserted through the vagina into the ovaries and the eggs are retrieved from the follicles. The eggs and sperm are prepared and suitably fertilized in a laboratory. The sperm is injected into the egg in cases where the sperm is weak and the process is known as Intracytoplasmic Sperm Injection (ICSI). The embryo (fertilized egg) is incubated for several days.
Under suitable conditions the embryo is transferred to the uterus of the patient or recipient. Usually more than one embryos are transferred using a small catheter through the cervix into the uterus. If there are more embryos than needed the rest are frozen for later use. The patient then is made to rest for a while before discharge. Suitable hormones are given to improve chances of conception.
There are different types of IVF methods adopted.
Cryopreservation (embryo freezing) is the freezing and thawing of "excess" embryos for later use. Embryologists have perfected techniques for sequentially transferring embryos to different solutions as they are frozen and thawed. Great care is taken not to rupture the membrane surrounding the embryo (zona pellucida).
The major advantages to using cryopreserved embryos in future IVF cycles is that the female does not have to undergo ovulation induction, which also dramatically reduces medication cost. Success rates are variable depending on patient characteristics, embryo quality and clinical history.
Gamete intrafallopian transfer (GIFT)
The woman receives hormones to stimulate development of the ovarian follicles, which are sac-like structures that contain the eggs. The sperm is obtained a few hours before the procedure. The sperm is washed and prepared for loading into the same catheter into which several of the best eggs which are obtained by transvaginal needle aspiration, will be placed.
The GIFT technique allows the eggs to fertilize and develop in the natural environment of the fallopian tube. The fertilized egg then makes their way to the uterus for implantation according to a normal timetable. The major advantages of this procedure over IVF is that the technique relies to a far greater degree on the body's natural processes and timetable to produce pregnancy, and is acceptable to those religious groups which avoid the more embryo invasive technologies. The fluid containing the eggs is placed in a laboratory dish and observed under a microscope. The egg is located and its stage of maturity noted. It is then carefully cultured in a special nutrient. Sperm and eggs are sequentially loaded into the catheter, which is then introduced into the patient's fallopian tubes through a tiny incision in her abdomen.
Intracytoplasmic Sperm Injection (ICSI)
Intra-Cytoplasmic Sperm Injection (ICSI) would be performed instead of regular IVF to fertilize the egg, when in situations the quality and count of the sperm is low. The eggs are retrieved the same as in a conventional IVF. The eggs and the sperm are then fertilized in the laboratory, by direct injection of a single sperm into each egg. Three days later the resulting embryos are simply placed into your uterus with no surgery, just as with IVF. Extra embryos are frozen for later attempts at pregnancy.
The availability of this Intra-Cytoplasmic Sperm Injection, "ICSI" technique means that men whose sperm previously were too weak or too few to fertilize in vitro (IVF), now have no problem fertilizing their wife's eggs. The fertilization rate per egg using ICSI is about 70% despite the sperm being terrible, the fertilization rate per infertile couple is over 99% if the wife has adequate eggs, and the pregnancy rate per treatment cycle is over 50%. This is not significantly different from regular IVF with normal sperm. Using this technique gives the same high chance for getting pregnant as any couple with normal sperm.
Assisted hatching is performed in order to help an embryo hatch out of its protective layering and implant into the uterus.
During the initial stages of development, your embryo is contained in a layer of proteins, known as the zona pellicuda which protects the embryo until it reaches the blastocyst stage of development. In order to successfully implant into the uterine lining, the embryo needs to hatch out of this zona pellicuda and attach to the walls of the uterus.
Sometimes, embryos have a difficult time hatching out of their protective layer. This can occur if the zona pellicuda is too thick or if the embryo does not have enough energy to break through the layer. Assisted hatching attempts to help these embryos break out away from the zona pellicuda by creating a small hole in this outer lining.
It is performed using micromanipulation techniques, under a microscope, during the fourth day of embryo development.
The embryo is first placed in a petrie dish containing culture solution. A special pipette is then used to hold the embryo in place. The embryologist takes a hollow needle that contains an acidic solution and places it next to the zona pellicuda. A tiny bit of this acidic solution is released from the needle so that it comes into contact with the zona pellicuda. This acidic solution begins to slowly digest the protective layering, creating a small hole. The embryo is then washed in a special solution and placed back inside an incubator until embryo transfer can take place.