STAGES OF IVF TREATMENT
Stimulation of the ovaries
For patients recommended to start IVF, the first treatment step is the stimulation of the ovaries.
On the second or third day of the menstruation cycle an ultrasound examination is performed, in addition, the blood estrogen levels in the blood are measured to help determine the drug dose to be administered to the patient. After the beginning of stimulation therapy, the patient is later invited for periodical check-ups. In these check-ups, vaginal ultrasonography is performed to assess the number and size of the developing follicles. Depending on the condition of the ovaries, additional blood estrogen level examination may be required.
The goal of the IVF treatment is to achieve the highest possible number of follicles with a diameter of 16-20 mm. During the follow-up examinations, the dose of medication can be adjusted depending on blood estrogen levels. The target is to reach 200 pg/ml level of estrogen for follicles larger in diameter than 14mm. Once the target follicle sizes are reached, in order to ensure maturity of follicles, 5000-10000 units of human chorionic gonadotropin (hCG) is injected. IVF Treatment durations vary, but on average in our clinic, this period lasts 10-12 days. Egg collection (OPU) is performed 34-36 hours after injection to aid the fracturing.
Another factor evaluated during follow-up ultrasound examination is the thickness and quality of the endometrial lining inside the uterus. Pregnancy occurs when the embryo settles on this endometrium. Therefore its quality is extremely important. If on the day of HCG, the thickness of the endometrium is less than 6 mm, the chance of pregnancy decreases.
Oocyte pick up
After oocyte maturation, oocyte pick-up (OPU) is performed. OPU is the collection of fluid-like follicles from the ovaries which are performed with the assistance of vaginal ultrasound. Under the microscope, oocytes can be seen in this fluid. OPU is a short procedure usually done with general anaesthesia. This procedure lasts 10-15 minutes.
Not all follicles contain oocytes. As a rule of thumb, 70% of the follicles contain oocytes. Several hours after OPU, the cumulus cells around the oocytes are cleared and analysed for maturity. For oocytes with good maturity, fertilization is performed. The patient is sent home after a resting period of 1-2 hours after OPU.
Fertilization is performed by either classical IVF or microinjection (ICSI) method. In classical IVF, sperm is placed next to the collected oocytes and naturally fertilize the oocytes. This technique is preferred when the infertility is due to the female and the male has no infertility issues. Microinjection (ICSI) is performed by inserting a single sperm into the oocyte using a device called a micromanipulator. Fertilization is performed 2-4 hours after OPU. Before microinjection is performed, the cumulus cells around the oocytes are cleared.
Around 70% of the collected oocytes are mature and ready for fertilization. For example, if 10 oocytes are collected, on average this will result in 5 well-developed embryos. If a PGD is to be performed, it is done at this stage before the embryo transfer.
Embryos can be transferred to the patient from a 2-cell stage to a multi-cell blastocyst stage. However, in general, the 4-8 cell stage is most preferred. Embryos achieve this stage usually in 2-3 days. Embryo transfer can be made on the 2nd - 6th day.
There is a direct correlation between the number of embryos transferred and clinical pregnancy rates. Best results are obtained when 2-4 embryos are transferred. When more than 2 embryos are transferred multiple pregnancy rates increase. However, this rate decreases for women with an older age. Due to the fact that multiple pregnancies increase the possibility of complications and an early birth, the number of embryos transferred in most countries is limited.
Nowadays, for women under the age of 35, only one blastocyst transfer is recommended. After a speculum is attached onto the vagina, the preparations are done for the transfer. The embryologist then brings the embryolan catheter containing the embryos to be transferred and these are released into the uterus by the doctor with the help of an ultrasound.
Embryo transfer process is not painful and usually does not require anaesthesia
After the procedure, in order to support the endometrium, some hormone drugs can be administered. This is called the luteal phase and if pregnancy occurs, the IVF treatment continues until the tenth week of pregnancy. If the pregnancy does not occur and menstruation begins, then this treatment is ended. If you would like to learn about IVF treatment costs, you can do so in our dedicated IVF costs page.