What are the reasons for the failure of IVF?

In vitro fertilization is a relatively complicated process. Generally speaking, there are many reasons for the failure of in vitro fertilization. Generally speaking, in vitro fertilization requires a long process. If there is a problem in any link, it will lead to the failure of in vitro fertilization, such as the quality of male sperm, the quality of eggs, the quality of female uterine environment, whether the embryo can implant, etc. There are many reasons.

Reasons for IVF failure

The first factor: age. Age is an important factor in the success of in vitro fertilization technology. According to reports, the highest success rate is between 25 and 34 years old, which can reach 45%. The success rate is between 26% and 30% after 35 years old. The success rate will decrease after 35 years old. The success rate is around 20% after 40 years old, and the live birth rate drops significantly. It also has a greater impact on eugenics. It is generally not recommended to use your own eggs for IVF if you are over 45 years old, because the success rate is too low and miscarriage, premature birth, stillbirth, etc. are prone to occur.

The second major factor: patient infertility, primary infertility at an older age, patients with endometriosis and polycystic ovary syndrome with severe uterine malformation, patients with severe oligospermia and azoospermia who cannot obtain sperm from the testicles, or those with a large number of deformed sperm, or those with deformed or developmental abnormal eggs, etc., all have a higher failure rate in IVF treatment.

The third factor: chromosomes. Among some couples with primary infertility or a history of adverse pregnancy, some couples have chromosomal mutations. Although pregnancy can be achieved through in vitro fertilization technology, the chromosomal mutation will greatly increase the chance of in vitro fertilization failure.

The fourth factor: the uterus. The endometrium is the main place for embryo implantation, so if the endometrium is damaged or has other lesions, the test tube baby will fail. New research has found that the endometrium secretes a special sugar molecule. When this sugar molecule is lacking, the pregnancy rate will be greatly reduced. I believe that in the near future, medical scientists will overcome this problem and improve the success rate of pregnancy.

IVF Process

In vitro fertilization requires a total of six steps, from the initial ovulation induction to the final pregnancy confirmation.

1. Ovulation induction therapy

When a couple who is planning to have a baby plans to have in vitro fertilization, the woman needs to undergo ovulation induction treatment first. This is because not every egg can be fertilized, and not every fertilized egg can develop into a viable embryo. Therefore, multiple eggs must be obtained from the female body to ensure that there are embryos that can be transplanted, which requires ovulation induction treatment for women.

The specific approach is that on the second day of the menstrual cycle, or when the results of reproductive hormones and uterine and ovarian ultrasound examinations meet the requirements, the woman starts taking ovulation-inducing drugs. The doctor judges the growth of follicles based on the results of ultrasound monitoring and serum hormone measurements and decides whether the dosage of ovulation-inducing drugs needs to be adjusted. When the follicles are mature, hCG injection is given to promote the final maturation of the egg. Egg retrieval is usually done 36-38 hours after hCG injection.

2. Egg retrieval

Under the guidance of B-ultrasound, the doctor uses a special egg retrieval needle to puncture the mature follicles through the vagina and suck out the eggs. Egg retrieval is usually performed under intravenous anesthesia, so the woman does not feel any pain from the puncture.

3. In vitro fertilization

Sperm retrieval: While the female retrieves the eggs, the male retrieves the sperm. After the semen has gone through a special washing process, the sperm and egg are placed in a special culture medium in the hope of natural combination. This is called conventional fertilization.

4. Embryo transfer

A few days after fertilization, a very thin embryo transfer tube is used to transfer the best embryo into the mother's uterus through the cervix. The number of embryos to be transferred is determined based on age, embryo quality and previous IVF outcomes. Usually 2-3 embryos are transferred. In recent years, in order to reduce the multiple pregnancy rate, some centers have chosen to transfer a single embryo, or a maximum of 2 embryos. Because the embryo transfer tube is very thin and the doctor's movements are gentle, the patient usually does not feel any pain.

5. Luteal support

Due to the use of GnRH agonists/antagonists and ovulation-inducing drugs, as well as the loss of granulosa cells caused by oocyte retrieval, women usually have luteal insufficiency during the oocyte retrieval cycle and need to use progesterone and/or chorionic gonadotropin for luteal supplementation/support. If pregnancy is not present, stop taking progesterone and wait for menstruation to occur. If pregnancy occurs, progesterone should be continued, usually until 3 weeks after the fetal heartbeat is seen on ultrasound.

6. Confirmation of pregnancy

Serum HCG is measured 14 days after embryo transfer to determine whether pregnancy is present. Serum HCG is measured again 21 days after embryo transfer to understand the development of the embryo. A transvaginal ultrasound examination is performed 30 days after embryo transfer to confirm whether there is intrauterine pregnancy and the presence of fetal heartbeat.