In Vitro Fertilization Process
In vitro fertilization, which literally means "fertilization in glass," is a process that involves several stages. Each step must be carefully timed and the intervals between them will vary by patient, so frequent monitoring will be necessary throughout the cycle.
In vitro fertilization ( IVF) and related assisted reproductive technologies at our practice in Northern California all depend on the ability to collect mature, healthy eggs from the ovaries. In order to trigger the maturation and release of several eggs at once, thereby increasing the chances of successful fertilization and implantation, the patient is given a course of fertility medications. The first administration of these medications is begun during the week prior to menstruation. The purpose of the medication is to prevent early ovulation, which would cause the IVF cycle to be cancelled. After menstruation occurs, the patient will begin receiving injections of gonadotropins, which mimic the naturally occurring hormones that are responsible for the maturation and release of eggs.
During this stage of IVF, the patient must be monitored carefully, through ultrasounds and blood tests, to be sure that the process is occurring as it should and to accurately predict the correct timing for egg retrieval. When it is determined that the eggs are ready, these medications are stopped, and the patient is given a single injection of human chorionic gonadotropin, or hCG, to trigger the final maturation of the eggs.
The egg retrieval stage of the in vitro fertilization process at our Roseville practice takes approximately ten minutes and is accomplished through an ultrasound-guided transvaginal aspiration. An ultrasound probe is used to visualize the ovaries, and a special needle is passed through the vaginal wall and into each ovarian follicle. Gentle suction is used to draw the egg out of the follicle and into a test tube. Intravenous sedation prevents the patient from experiencing any discomfort during the procedure, and recovery time is brief.
Once the eggs are collected, they are examined by an embryologist and placed in a special IVF media. At this time, the sperm sample is collected and processed as well. Once both the eggs and sperm have been prepared, they are combined in a carefully controlled environment and left to fertilize for approximately 18 hours.
After 18 hours, the eggs are examined under a microscope to identify the ones that have been successfully fertilized. The new embryos are then incubated and examined daily for three to five days. Following this, the best embryos are selected for transfer.
Like the egg retrieval procedure, embryo placement takes only a few minutes and involves minimal discomfort. First, a thin catheter is threaded through the cervix. The embryos are then placed in a smaller catheter, which is passed through the first catheter and into the uterine cavity. Once the embryos are deposited into the uterus, both catheters are withdrawn.
For the best chances of pregnancy with minimum risk of a multiple birth, only two to four embryos are placed during any given IVF cycle. Any remaining embryos can be cryopreserved for placement at a later date.
After embryo placement, the patient is advised to stay home and rest for two days. Ideally, hatching and implantation will take place during this time.