In-Vitro Fertilization (IVF)
In-Vitro Fertilization is a form of Assisted Reproductive Technology in which sperm and eggs are mixed in a laboratory petri dish to achieve fertilization. Advanced insemination techniques may complete this with injecting a single sperm into an egg, also called intra-cytoplasmic sperm injection (ICSI). IVF is used to treat many causes of infertility, but all of them has the following basic steps:
Step 1: Ovarian Stimulation Treatment
- Fertility drugs are taken to induce ovaries producing multiple eggs usually for 8 to 14 days. Multiple eggs are stimulated since not every egg will fertilize or develop after fertilization in a lab dish. During this step, the woman will have frequent ultrasound examinations and blood works to monitor the development of ovarian follicles and check hormone levels. When the follicles are ready, a trigger medication is administered, which will cause the final state of egg maturation and helps us to time the egg retrieval procedure.
Step 2: Egg Retrieval Procedure
- The eggs are retrieved usually 34 to 36 hours after the trigger medication injection by trans-vaginal ultrasound aspiration. The physician use a needle attached to the ultrasound probe to drain fluid from the follicles, and embryologist checks this fluid for the egg. The number of eggs retrieved varies based on several factors including stimulation protocol, the age of the woman, etc.
Step 3: Insemination
- Sperm collected manually or surgically can be used for insemination in the laboratory and based on the quantity or quality of this specimen embryologist would decide to use either conventional insemination techniques or ICSI. Conventional insemination is when the male’s sperm is placed together with the oocytes in a lab dish. When the sperm is injected directly into the egg called ICSI.
Step 4: Embryo Culture
- One day after the insemination zygote should be formed confirming fertilization. Fertilized eggs will divide and become 2 to 4 cell embryos 2 days later. Embryos that have developed for about 5 or 6 days are called blastocysts. PGS has been mostly performed on blastocyst stage embryos, after the biopsy of several cells from the outer layer called trophectoderm.
Step 5: Embryo Transfer or Embryo Freezing
- At end of laboratory culture phase, embryos are either placed into the woman’s womb for implantation or cryopreserved for future use. No anesthesia is necessary for the embryo transfer procedure. The number of embryos transferred depends on the condition of each patient, i.e. embryo quality, patient’s age, and previous IVF results and so on. Patients can use remaining embryos for the future cycles by cryopreservation. Cryopreservation of embryo makes future cycles much simpler and less expensive as a woman does not need to go through whole IVF process over again.