Fertilization Process

Once the medical tests have been completed and the results are received, a tailored treatment protocol is set, specific to the problems of the couple. The doctor and nurses of the unit will give details of the treatment process as well as detailed instructions both verbally and in writing.

Whilst being individually tailored, the treatment principles are similar and include medications (Gonal-F, Puregon, Menogon, Menopur, Metrodin) designed to encourage recruitment of a number of follicles in the ovaries, compared to the single follicle that normally develops. These drugs are combined with other drugs (Synarel, Decapeptyl, Cetrotide, Orgalutran) given to prevent the onset of independent ovulation during follicle recruitment and prior to their aspiration from the ovaries.


Phase I - Inducing Ovulation
The treatment cycle begins on the 21st day, or the first day of the menstrual cycle. Before starting treatment you will be asked to undergo an ultrasound of the ovaries to make sure that they do not have cysts that may interfere with the treatment, as well as testing of the ovarian hormones, estradiol and progesterone, to ensure that their level corresponds to the current stage of your cycle.

Inducing ovulation is done by giving drugs that encourage ovulation, such as Gonal-F, Puregon, Menogon and Menopur. At the same time as these drugs, and depending on the type of treatment provided to you, GnRH (Decapeptyl, Synarel, Cetrotide, Orgalutran) will be used in parallel to prevent unwanted premature ovulation. Monitoring of the ovarian response is done with ultrasound and blood tests. When the developing follicles reach the desired size, you will be given a shot of human chorionic gonadotropin (hCG - Ovitrelle, Pregnyl, or Chorigon) for final maturation of the eggs.

Phase II - Ovarian Puncture
Follicular aspiration is performed using a transvaginal ultrasound transducer that helps to detect the location of the ovarian follicles. The needle attached to the transducer pierces the follicle and draws out the egg from inside it. The procedure is performed under a local, mild anesthetic and takes about 30 minutes.

The follicular fluid aspirated from the follicles is delivered to a technician in the IVF laboratory to identify and quantify the ova, which are isolated from the follicular fluid. The eggs isolated into the petri dishes are fertilized with sperm prepared in advance. The dishes containing the eggs with the sperm are returned to an incubator, and the next morning it can be determined whether normal fertilization has occurred. In the event that normal fertilization has happened, the fertilized eggs continue to develop into embryos and are typically transferred to the uterine cavity after an additional 24-48 hours.

Placement of multiple embryos carries the risk of multiple pregnancy. In order to avoid multiple pregnancies associated with preterm births, the recommendation is to transfer 1 or 2 embryos back to the uterine cavity.

In other cases, the embryos can continue to grow in the laboratory until they have reached the blastocyst stage (5-7 days from aspiration of the eggs) and can be transferred to the uterus at this time. While the pregnancy rate obtained from the return of the embryos at the blastocyst stage is higher than that when returning embryos at an earlier stage, only 40% -50% of embryos reach that stage in culture.

Phase III - Embryo Transfer
The return of embryos to the uterus is a simple procedure and is done without anesthesia. The process is similar to that of a routine gynecological examination, and the same as that of injecting sperm into the uterus. The embryos are returned via a small, thin catheter which contains the embryos, inserted through the cervical canal into the uterine cavity. After insertion of the catheter, the contents are expelled and the embryos are deposited into the uterus and the tube is taken out.

After injecting drugs used for ivf, you may experience mild pain.

Ovarian hyperstimulation syndrome may occur in 1-5% of the women on whom egg extraction is performed. When ovarian hyperstimulation appears severely (in less than 1% of cases), it may lead to the accumulation of large amounts of fluid in spaces of the stomach and lung with blood clotting disorders and risk of emboli. Sometimes, cycles are eliminated to avoid over-stimulation. If abdominal pain and shortness of breath appear after returning the embryos, it is important to check with a doctor immediately.