IVF treatment requires the participation of both the couple and the medical team and it is a long and tiring process. Despite recent developments in this field, it is not possible for every couple to achieve pregnancy. The success of the treatment depends on female age and female ovarian rezerve.
If the female partner is younger than 35 and has adequate ovarian rezerve, the cumulative pregnancy rate after 3 treatment cycles is 80%. In other words, 80 of 100 couples who started IVF treatment are expected to become pregnant.
In contrast, if the female partner is older than 35 and has diminished ovarian rezerve, the results are not so promising. Pregnancy rate begin to decline at 35 years of age and it is lower than %20 after 40 years of age.
IVF treatments consist of 3 steps. The treatment begins with the stimulation of ovaries to retrieve more than one oocyte. The next step is oocyte retrieval and fertilization. After fertilization, embryos are kept in incubators in embryology laboratory. Embryo transfer is planned on day 2-3 or 5 depending on clinicians’ practice. A pregnancy test is performed after 12-14 days after treatment.
Although treatment protocols are similar, the success of treatment depends heavily on laboratory conditions, medical teams experience, embryo transfer policies and these parameters varies amongst different clinics. IVF clinic are under pressure from the patients and other clinics about the number of embryos being transferred, but transferring more than two embryos increases multiple gestation rates. In most of the European countries and Australia, there are legal limitations about the number of transferred embryos. In Turkey, legal regulations prohibit transfer of multiple embryos. If the female partner is younger than 35, the first two cycles of the patient must be performed with single embryo transfer; after that two embryos per cycle can be transferred. If the female partner is older than 35 years, two embryos can be transferred per cycle. Under no circumstances, more than two embryos can be transferred per cycle in Turkey.
CONTROLLED OVARIAN STIMULATION
One of the primary goals of IVF treatment is to develop more than one oocyte to increase pregnancy rate. Under normal circumstances, only one oocyte is preperad to ovulate each cycle. By this oocyte we can get pregnancy in %25 of couples if there are no additional problems affecting them. Some of these pregnancies are lost because of various medical resons. Consequently monthly live birth rate is about %20.
There are some principles about oocyte preperation:
- The number of oocytes retrieved should be in the ideal limits which is 10 to 15. Excessive number of oocyte development may results in ovarian hyperstimulation syndrome (OHSS) whicih is a risky clinical conditon for women. Care should be taken to avoid OHSS.
- Premature ovulation must be avoided during ovarian stimulation, for this purpose different medications are used to effect the spesific signals originating from brain.
- Premature luteinization must be avoided during ovarian stimulation to have normal quality oocytes and normal pregnancy rates.
- Oocytes should develop synchronously.
- The oocytes must be mature and ready to fertilize after oocyte retrival .
There are two protocols frequently used for ovarian stimulation, these are long and short protocols. Regarding female age, ovarian reserve and clinicians choice, one of the protocols are selected to perform ovarian stimulation.
The oocytes are collected from the vaginal route under ultrasound guidance once their maturation is complete. This is a painful procedure and is performed under anesthesia.
The procedure usually takes 5 to 20 minutes. After 1-2 hours, the patients become ready for discharge from the clinic.
After oocyte pick up, oocytes retrieved from the female partner are fertilized by the spermatocytes of the male partner in the IVF laboratory. There are two types of fertilization technique:
- Spermatocytes and oocytes are brought together in the medium. Spermatocytes fertilize the oocytes by themselves. This is conventional in vitro fertilization (IVF) treatment.
- A spermatocyte is injected into every oocyte by using special devices and technique under microscopic visualization. This is intracytoplasmic sperm injection (ICSI) procedure, also called as microinjection. If the number of sperms is too low, sperm functions are impaired or in case of unexplained infertility, microinjection (ICSI) is the treatment of choice.
The occurance of fertilization is controlled after 16-18 hours from the procedure.
Embryo transfer is the last step of the IVF treatment. It can be done on day 2-3 or 5 depending on the patient’s condition. Legal legislation in Turkey dictates single embryo transfer for women younger than 35 years of age. If the couple can’t achieve pregnancy after two single embryo transfer cycles, two embryos can be transfered in the subsequent cycles. If the patients age is above 35, two embryo transfer per cycle can be performed. In Turkey, transferring more than two embryos per cycle is prohibited by law.
The embryo transfer procedure is performed under pelvic ultrasound guidance. For better visualization, the patient’s bladder should be filled to an optimum level. The procedure is painless and doesn’t require anesthesia.
The patient should rest for 30 to 60 minutes after the procedure. After that period the patient can return to her daily activities. In some clinics, it is advised to rest until the pregnancy test day but there is no evidence supporting this clinical management.