Reasons for IVF implantation failure

The main reason why test tube transplantation cannot implant normally is that the quality of the embryo is not good enough, the female friend is too old and the endometrial environment does not meet the standards. Therefore, when we do test tube transplantation, we must first check the health of the female friend’s uterus. Only when the uterus meets the environment for conception can the transplantation be performed. You can learn about the content of the article about the transplantation method of in vitro fertilization.

What is the reason why the blastocyst transfer of IVF did not implant?

1. The embryo is not of good quality. The quality of the embryo directly determines whether it can implant. If there are potential problems with the embryo, it may stop developing after being transplanted into the uterus, resulting in implantation failure.

2. Older age. The fertility of older women gradually declines, so the earlier IVF is performed within the childbearing age, the higher the chance of embryo implantation.

3. The woman’s psychological quality is not good enough. The woman's psychological and mental state is one of the factors that affect embryo implantation. Excessive mental stress can easily cause endocrine disorders, thus affecting the embryo's implantation rate. Therefore, women should relax and release stress.

4. The endometrial environment does not meet the standards. The endometrium is where the embryo implants. If the endometrium is damaged, embryo implantation will be hindered. Therefore, a comprehensive physical examination is required before undergoing IVF treatment. If there are abnormalities in the endometrium, treatment should be performed first to improve the environment for embryo implantation before undergoing IVF. This is the only way to ensure the embryo implantation rate.

How IVF works

1. Controlled superovulation

Since the length of the menstrual cycle varies from person to person and there are also differences between different cycles of the same patient, it is not easy to arrange the time for egg retrieval. In addition, only one dominant follicle develops in the natural cycle, and only one embryo can be formed after fertilization. The pregnancy rate of transplanting one embryo is very low. Therefore, controlled superovulation is needed to enhance and improve ovarian function, so as to achieve the goal of not being restricted by the natural cycle, obtaining multiple healthy eggs, providing multiple embryo transplants, and synchronizing corpus luteum development with endometrial function as much as possible. Controlled superovulation usually involves using GnRHa to downregulate FSH and LH in the body, and then administering HMG or FSH ovulation drugs to stimulate the growth of follicles in the ovaries. The drug dosage is adjusted based on the patient's responsiveness to the drug. The number of eggs obtained will vary depending on the patient's age and drug dosage.

2. Monitoring follicles

In order to evaluate the effect of ovarian stimulation and determine the time for egg retrieval, vaginal B-ultrasound is required to monitor the size of follicles, and blood tests are conducted to check the E2 value (estrogen) 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 larger than 1.4 cm is equivalent to the E2 value, human chorionic gonadotropin (hCG) can be injected to promote follicle maturation. Egg retrieval is done 34-36 hours after hCG injection.

3. Egg retrieval

The most commonly used method of egg retrieval is to insert the egg retrieval needle through the vaginal vault and directly reach the ovary to absorb the eggs under local anesthesia and then immediately transfer the eggs to a culture dish containing embryo culture medium under a microscope and culture them in a 37°C incubator.

4. Sperm collection

Sperm retrieval is done on the same day as egg retrieval. Wash your hands before collecting semen and use masturbation to collect semen. The small cup given is sterile. Do not touch the rim or inside of the cup when taking the liquid. The semen was extracted and processed by swim-up method or Percoll density gradient centrifugation.

5. In vitro fertilization

4-5 hours after egg retrieval, place the processed sperm and eggs in the same culture dish. After culturing them together for 18 hours, the fertilization can be observed under a microscope. If the sperm quality is too poor to allow natural fertilization, forced fertilization must be achieved by microinjection (see intracytoplasmic sperm insemination).

6. Embryo transfer

The fertilized egg can develop into an 8-16 cell embryo after 48-72 hours of in vitro culture. At this time, the number of embryos to be transplanted is determined based on the patient's age, whether she has been pregnant before, and the quality of the embryos. Excess embryos can be frozen and stored. Embryo transfer generally does not require anesthesia. Currently, embryos are usually transplanted 2-3 days after fertilization. I use embryo transplantation 3-5 days after fertilization. The later the embryo transfer is delayed, the higher the requirements for in vitro culture conditions will be. However, delaying the transfer is more in line with the physiology of pregnancy. At the same time, it can also eliminate inferior embryos through natural selection, thereby increasing the pregnancy rate and reducing the multiple birth rate.

7. Hormone supplementation after embryo transfer

Currently, we mostly use injections to give progesterone to support the corpus luteum. If pregnancy is confirmed, hCG supplementation is continued until the 10th week of pregnancy.

14 days after embryo transfer, pregnancy can be confirmed by urine test or blood draw.