In vitro fertilization-embryo transfer, commonly known as IVF, is an advanced artificial assisted conception technique. It uses artificial methods to fertilize egg cells and sperm outside of the body for early embryonic development, and then transfer them to the mother’s uterus to develop a baby.
Some couples of childbearing age want to have a child but are unable to do so due to medical reasons. With the development of biological science and medical research, there is finally a remedy for such couples – they can hope for a lovely baby through IVF technology. Li Yanmin, Department of Reproductive Medicine, Weifang People’s Hospital
I. Principle
”IVF is not a real baby grown in a test tube. Instead, a few eggs are removed from the ovaries, combined with the male partner’s sperm in a laboratory to form an embryo, which is then transferred to the uterus, where it is laid in the mother’s womb and becomes pregnant. Normal conception requires the sperm and the egg to meet in the fallopian tube, the two unite and form a fertilized egg, which then returns to the uterine cavity to continue the pregnancy.
II. Development of IVF technology
The first generation: In 1978, British experts steptoe and E. Dowrds customized the world’s first IVF, which is known as a miracle in the history of human medicine.
The second generation: In 1992, ICSI was first successfully applied in humans by Dr. Palermo and Dr. Jiaen Liu from Belgium, which greatly expanded the indications for IVF technology, especially for men with severe oligospermia, obstructive azoospermia and sperm acrosome enzyme deficiency.
The third generation: Based on artificial fertilization and microscopic operation, pre-implantation genetic disease diagnosis (PGD) has been developed and used clinically, which helps human beings to select the healthiest offspring from the perspective of biogenetics and provides future parents with genetic diseases the opportunity to have healthy children.
III. The Process
So what exactly is the process of IVF? After a period of incubation, the sperm-egg can fuse to form a fertilized egg and divide to 4-8 cells, then 2-3 of the best developed embryos are selected and placed back into the The two or three best developed embryos are then selected and placed back into the uterine cavity for further growth and development. If there are any remaining embryos, they can be frozen at ultra-low temperature and can be selected for future transfer.
IV. Steps
1. Controlled ovulation: Since the length of the natural menstrual cycle varies from person to person and varies from cycle to cycle in the same patient, it is not easy to schedule egg retrieval, and only one dominant follicle develops in the natural cycle, only one embryo can be formed after fertilization, and the pregnancy rate of transferring one embryo is very low. Therefore, controlled superovulation is needed to enhance and improve ovarian function in order to obtain multiple healthy eggs regardless of the natural cycle, to provide multiple embryos for transfer, and to synchronize corpus luteum development with endometrial function as much as possible.
2. Follicle monitoring: In order to evaluate the effect of ovarian stimulation and to decide the timing of egg retrieval, vaginal ultrasound should be used to monitor the follicle size, together with blood sampling to check the E2 value and adjust the dosage of medication. When two to three or more follicles are larger than 1.8 cm in diameter and the number of follicles above 1.4 cm is comparable to the E2 value, human chorionic gonadotropin (HCG) can be injected to promote follicle maturation. The eggs are retrieved 34~36 hours after the hCG injection.
3. Egg retrieval: Under local anesthesia, the needle is passed through the vaginal fornix under vaginal ultrasound guidance to the ovaries and the eggs are immediately transferred under the microscope to a culture dish containing embryo culture fluid and incubated in a 37°C incubator.
4. Sperm retrieval: The sperm is removed on the same day as the egg retrieval. Wash your hands before sperm retrieval and use the masturbation method to retain semen. The small cup given is sterile and do not touch the rim of the cup or the inside of the cup when leaving it.
5. In vitro fertilization: 4 to 5 hours after egg retrieval place the processed sperm and eggs in the same Petri dish and incubate together for 18 hours, then fertilization can be observed under a microscope. If the sperm quality is too poor to allow natural fertilization, fertilization must be forced by microinjection.
6.Embryo transfer: The fertilized egg can develop into an 8~16 cell stage embryo after 48~72 hours of in vitro culture. At this time, the number of embryos to be transferred is determined by the patient’s age, whether she has been pregnant or not, and the quality of the embryos, and the excess embryos can be frozen and preserved. Embryo transfer generally does not require anesthesia. Currently, most of the embryos are transferred 2~3 days after fertilization.
7. Progesterone supplementation after embryo transfer: At present, we mostly use the injection method to give HCG and progesterone to support the corpus luteum. If pregnancy is confirmed, supplementation is continued until 10 weeks of pregnancy.
8. 14 days after embryo transfer, the pregnancy can be determined by urine test or blood sampling.
V. Applicable groups
1.Severe tubal disease, such as tubal blockage and hydrocele caused by pelvic inflammatory disease; or tubal tuberculosis with normal endometrium; or tubal blockage after ectopic pregnancy surgery
2, endometriosis
3, immune infertility, the presence of anti-sperm antibodies in the semen of the male partner or the cervical mucus of the female partner
4. male factor, i.e. oligospermia, weak spermia, teratospermia
5. Infertility of unknown origin
6. Other causes of infertility that have not been treated
7.Hereditary diseases requiring pre-transplant diagnosis
8.Other: such as follicle non-rupture syndrome, etc.
VI. Success rate
From the birth of the first “test tube baby” more than 20 years ago to today, human assisted reproduction technology has developed greatly. Especially in recent years, because of the maturity of various technologies, including the perfection of cell culture fluid and the rich experience of medical personnel, its success rate has gradually increased worldwide, from the original 20%-25% to 60% or even higher.
VII. Preparations needed for IVF
To do IVF, you must have a marriage certificate, couple’s ID card and birth certificate.
The woman needs to complete some basic tests, such as chromosome, hysterosalpingogram, immune antibody, prenatal 4 tests, routine blood, coagulation routine, and basic endocrine hormones. If there is no abnormality, the doctor will create a medical history for you and tell you when to start IVF treatment. The male partner will need to have semen tests, chromosomes and some other routine tests.
The medication is usually started at mid-luteal phase, i.e. day 21 of menstruation, to keep the gonadotropins in the body at low levels. Intramuscular follicle development medication is started on day 3-7 of menstruation and the dose is adjusted through close monitoring. The eggs are retrieved when the follicles are mature. The subsequent steps are moved to the laboratory for the final selection of good quality embryos for transfer. The whole process is minimally painful and usually does not require hospitalization. One cycle costs 20,000 to 30,000 RMB.
Factors that affect the pregnancy rate of IVF
1, the age of the woman: the impact of age on reproduction is crucial, at the age of 36, the monthly conception rate of a normal woman is reduced by half. By the age of 45, the average monthly conception rate is only about 1 percent. The success rate for women between the ages of 25 and 35 is higher than the average of 30-40%, with some reaching 50% or higher, but after the age of 35 the success rate gradually declines, reaching only about 20% by the age of 40.
2. Ovarian function: Ovarian function refers to the responsiveness of the ovaries to ovulation-promoting drugs. The poorer the ovarian function, the fewer eggs are obtained and the poorer the quality of the eggs, the lower the pregnancy rate and the higher the miscarriage rate. In addition to age, ovarian function is also associated with inter-individual differences. In addition, ovarian surgery, especially ovarian cyst debridement and ovarian electrocoagulation, can seriously damage the ovarian structure and function of the ovaries.
3. Hydrosalpinx: Hydrosalpinx is also an important cause of infertility, and if a patient with hydrosalpinx wishes to have an IVF, the pregnancy rate is lower than that of a patient without hydrosalpinx, and the rate of miscarriage and ectopic pregnancy is greatly increased. Therefore, it is crucial to treat hydrosalpinx before IVF treatment.
4. Uterine function: Patients with severe damage to the endometrium, if the endometrial thickness is less than 7 mm in superovulatory cycles, will have a low pregnancy rate and high miscarriage rate when IVF is performed, and there is no reliable method to treat them. In addition, although uterine malformation does not affect the pregnancy rate of IVF, the miscarriage and preterm delivery rates are high and the live birth rate is low, so it is best to undergo corrective surgery before IVF so as to improve the pregnancy prognosis and increase the pregnancy rate of IVF.
5, in addition to the above points, there are some sociological factors that have an impact on the pregnancy rate of IVF, such as: the patient’s own psychological factors, the social environment in which the patient lives, etc.