In vitro fertilization (IVF) is the most effective, widely practiced infertility treatment in the world. First, IVF is a series of procedures that involve the fertilization of an egg outside of a woman’s body in a private laboratory. Gynecology, Obstetrics and IVF Specialist Op. Dr. Seval Taşdemir explained the egg development methods in IVF treatment for you.
IVF treatment is usually done after other methods of trying to get pregnant have failed. Here is IVF step by step:
PREPARING FOR THE IVF CYCLE
Before IVF, the uterus and fallopian tubes are evaluated to make sure there are no problems requiring surgical repair. Pre-cycle testing includes hormonal evaluation to assess thyroid function and ovarian reserve, screening both partners for STI, and semen analysis of the male partner.
The expectant mother takes fertility drugs for ovarian stimulation for 8-14 days; This period is an average of 10-11 days. Ovarian stimulation is used to mature multiple eggs for egg retrieval. Even if ovulation is normal, fertility drugs are used to produce more than one egg because with more eggs, pregnancy rates are higher. For IVF, the number is usually between 10 and 20. However, not all of them are suitable for use, as on average only about two-thirds have proper maturity.
Your doctor designs a careful protocol to try to obtain the maximum number of eggs while protecting against the development of ovarian hyper-stimulation syndrome (OHSS). Fertility drugs for IVF are usually injected and you will be monitored frequently using hormonal tests and vaginal ultrasounds for best results. When an ultrasound determines that you have enough large enough follicles and that your estrogen levels are at the right level, you will receive a trigger hCG or other medication. This replaces a woman’s natural surge of luteinizing hormone that encourages the final stage of egg maturation so that the eggs can become fertilized.
34 – 36 hours after receiving the trigger needle – before the eggs are ovulated – a surgical procedure is performed to remove the eggs from the follicles in your ovaries. For this egg collection procedure, an ultrasound is used to visually guide a small needle through the top of the vagina into one ovary and then the other. You will not feel any pain or discomfort during the procedure as you will be under sedation via IV while being closely monitored by the anesthesiologist.
The follicles are entered with a needle and the follicular fluid contents are removed with a gentle suction that brings the egg in the liquid; The whole process usually takes less than 30 minutes. You may feel a slight cramp on the day of the procedure, which usually goes the next day. There may be a feeling of fullness and/or pressure due to enlarged ovaries due to ovarian stimulation. This may take several weeks.
The fluid from the follicles containing the egg is sucked by the IVF doctor through a small tube and into a test tube. The test tube is then given to an embryologist, who uses a microscope to locate the egg in each follicular fluid test tube. All details of the eggs are carefully recorded. The number of eggs produced and removed is affected by the patient’s age, ovarian reserve, response to ovarian stimulation, and sometimes the ability to access the ovaries with a needle.
Once the eggs reach the lab, experts examine them to determine maturity and quality. Mature eggs are transferred to a special culture medium, placed in an incubator and fertilized with sperm a few hours after the egg is collected. There are two ways to fertilize an egg: conventional insemination or intracytoplasmic injection (ICSI). Which procedure will be used will be determined by your IVF team (doctors and embryologists) and will depend on many factors related to the couple going through IVF. Both methods have approximately the same success rate. ICSI is used approximately 70% of the time when factors reduce the likelihood of fertilization due to poor semen quality or previous IVF failure.
For the traditional method, sperm are placed in culture medium in a small petri dish containing an egg; Sperm and eggs are incubated together in the container in the laboratory, allowing the sperm to enter the egg on its own. For ICSI, a sperm is injected into the cytoplasm of the egg using a needle and a sophisticated operating microscope. No matter what action is taken, fertilization is checked the next morning.
Following fertilization, the IVF team and couple determine exactly when embryo transfer will occur (between 1 and 6 days, but usually 3-5 days after egg retrieval). However, if genetic testing is decided upon, a biopsy of the embryo is almost always cultured first on day 5 or 6 and remains in the IVF laboratory. After the genetic test results are obtained, the selected embryo is selected, thawed and transferred to the uterus, usually within 1-2 months after the egg is collected.
The number of embryos produced depends on several factors, including the age of the couple. In the past, multiple embryos were transferred in hopes of maximizing success, but this often resulted in twins or, rarely, triplets, both of which were associated with preterm birth and other serious complications for both infants and mother.
The safest approach is to limit transfer to a single embryo. To maximize the chance of success, the healthiest embryo is selected based on a grading system used by the embryologist to evaluate each embryo.
A soft, flexible and thin catheter is used to transfer the embryo to the uterus. An abdominal ultrasound is used to ensure that the tip of the catheter is in the best position to implant the embryo. Pain and discomfort are rare and the experience has been compared to how it feels to have a pap smear. Good embryos not used for transfer are usually frozen if the cycle is not successful or if a couple wants more children after a successful first cycle. The development of the embryo continues in the uterus and within 1-2 days following embryo transfer, the embryo emerges from the egg and is implanted in the uterine lining.
About 12 days after embryo transfer, a blood pregnancy test is done. If pregnancy is confirmed, it is followed by blood tests and then ultrasonography to confirm viability and whether there is a multiple pregnancy. If the pregnancy seems normal at 9-10 weeks, routine check-ups are continued.