The complete process of third-generation in vitro fertilization can be divided into six steps: establishing a patient profile and conducting pre-treatment examinations, ovulation induction therapy, egg retrieval and sperm collection, in vitro fertilization and embryo culture, PGT genetic screening, and embryo transfer and pregnancy testing. Compared to the first and second generations of IVF, the main difference between the third generation is the addition of genetic testing before embryo transfer. In terms of duration, each step typically takes two to three months if everything goes smoothly. If adjustments or interruptions are necessary during the process, the duration may be extended accordingly. The exact timeline will be determined by the evaluation of the attending physician.
1. What are the differences between third-generation IVF and the first and second generations?
The process of first- and second-generation IVF involves ovulation induction, egg retrieval, fertilization of eggs with sperm in vitro, and then transferring the embryos back into the woman's body. Generally, no genetic screening is performed on the embryos before transfer. Third-generation IVF adds pre-impaction genetic testing to this process.
**PGT (Pre-Gestational Transfer)** step: When the embryo develops to the fifth or sixth day in the laboratory and becomes a blastocyst, doctors will extract a small amount of trophoblast cells for analysis. The chromosomes of the embryo are examined, and those that meet certain criteria are selected for transfer. This procedure is primarily aimed at individuals who are at risk of genetic diseases or suffer from recurrent miscarriages.Depending on the objective of the test, PGT can be divided into three categories:
● PGT-A: This method is used to detect abnormalities in the number of chromosomes in embryos. It is particularly useful for women who are older and planning to conceive.
● PGT-M: This method is used to detect single-gene genetic disorders. It helps to reduce the risk of related genetic conditions.
● PGT-SR: This method is used to detect chromosomal structural abnormalities. It is suitable for individuals who have chromosomal rearrangements or other genetic issues.
II. Detailed Explanation of the Six Steps of the Third Generation of In Vitro Fertilization
1. Establishing a medical record and conducting pre-operative examinations (results will be available in about 1-2 weeks)
Both husband and wife need to...
Complete the necessary procedures at the hospital where you seek treatment, including preoperative examinations. For women, these typically include tests related to sex hormones, ultrasound scans, infections, and cardiac function. Men need to undergo semen analysis; the specific tests will be determined by the attending physician. Results are usually available within one to two weeks. Based on these results, doctors will determine whether it is suitable for starting the cycle. For a detailed list of tests and schedule, please refer to Articles 1-4 under "Common Questions" at the end of the document.2. Ovulation induction treatment (approximately 10-14 days)
Women receive ovulation induction injections, and the treatment usually lasts for ten days.
About fourteen days later, it is necessary to visit the hospital regularly for ultrasound examinations to monitor the development of the follicles. The doctor will then adjust the medication based on these results.3. Egg and sperm retrieval (about 36 hours after the night injection)
When the follicles have developed to the required level, a "night injection" will be administered. Approximately 36 hours later, the doctor will perform the egg retrieval procedure under anesthesia. The entire process usually takes just a few minutes. On the same day, the man will provide a sample of his sperm.
4. In vitro fertilization and embryo culture (3-6 days)
The laboratory will carry out intracytoplasmic sperm injection (ICSI) to fertilize the eggs. The embryos will then be monitored in a culture environment. Usually, the embryos develop into blastocysts on the fifth or sixth day.
5. PGT genetic screening (report will be available in about 7-14 days)
Extract three to five trophoblast cells from each blastocyst for testing. It usually takes 7 to 14 days to get the test results. The report will indicate the chromosomal status of each embryo, which can be used as a reference for selecting the embryos for transplantation.
6. Embryo transfer and pregnancy testing (7-14 days after transfer)
; font-size: 16px;">Select the embryos that have passed the screening process for transplantation (usually using frozen embryos). Seven to fourteen days after transplantation, go to the hospital for a blood test to determine whether the embryo has successfully implanted.
| Step | Estimated Duration | Key Points |
| Establishing a pregnancy record and preoperative examinations | Results will be available in about 1-2 weeks | Both parties undergo medical examinations: the woman's hormones, ultrasound, infection tests, cardiac function; the man undergoes semen analysis. |
| Ovulation stimulation therapy | Duration: approximately 10-14 days | Injection therapy plus regular ultrasound monitoring of follicle development |
| Egg and sperm retrieval | Approximately 36 hours after the night injection | Egg retrieval is performed under anesthesia (lasting about ten minutes); sperm retrieval is done on the same day |
| Fertilization and embryo culture | Duration: 3-6 days | ICSI (intracytoplasmic sperm injection) is used to fertilize the eggs. Embryos are cultured until they reach the blastocyst stage (day 5-6) |
| PGT screening | Results are available in approximately 7-14 days | 3-5 trophoblast cells from each blastocyst are sent for analysis |
| Transplantation and pregnancy testing | Pregnancy testing should be done 7-14 days after transplantation | After embryo transfer, blood tests are performed to confirm implantation |
III. Key differences between first-generation, second-generation, and third-generation technologies
| First generation / Second generation | Third generation | |
| Screening phase | None | PGT testing |
| Duration of the cycle | Approximately..."One and a half months to two months | Approximately two to three months |
| Wait after egg retrieval | Transplantation can be scheduled within three to five days | Wait for 7-14 days for PGT results |
| Cost breakdown | - | Additional PGT testing is included in the regular cost |
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