In vitro fertilization procedure involves the collection of eggs from the female’s ovaries and fertilising with the sperm. IVF treatment is typically recommended to patients who have already had failed outcomes in natural conception. Also, following failed cycles of artificial insemination your doctor may advise for IVF. You may need it in cases of absent or injured fallopian tubes, endometriosis as well. Low sperm count or poor sperm motility in the male partner, ovulation and immune disorders are some of the indications. Women with advanced maternal age or requiring pre implantation genetic diagnosis (PGD) will also need IVF treatment. However, IVF can also give negative results due to fertilization failure & is a disastrous consequence of fertility treatment.
What are the laboratory methods of fertilization?
There are 2 methods to inseminate eggs:
1. Through Traditional IVF: This method involves putting the prepared semen sample in contact with the eggs in a dish. It is used when no serious sperm issues exist. In other words, if the semen sample has a good motile sperm count method can be applied.
2. Through Sperm Micro-Injection (ICSI): With this procedure the sperm is introduced into the cytoplasm of the mature egg. It is used when there is a severe male factor such as serious abnormalities with sperm motility, concentration or morphology. Cases, in which the sperm retrieved from a testicular biopsy, also require the use of ICSI. The same goes for cycles where cryopreserved sperm or vitrified eggs are being used.
Some fertility centers prefer to use ICSI, even if the requirements for a cycle of traditional IVF are met. This is done to ensure a good fertilization rate for better success.
What Is Fertilization Failure?
After the oocytes have been inseminated using IVF or ICSI, we can know the result the very next day. Embryologists calculate the number of fertilized eggs, or pre-embryos, in the reproduction laboratory after 15 to 18 hours of IVF. The term fertilization failure is used when none of the inseminated eggs have fertilized, or the fertilization rate is low. This situation occurs in 11% to 15% of traditional IVF cycles, and in about 3% of ICSI cycles.
What can go wrong?
Before starting the IVF treatment you should understand the limitations of IVF treatment. Failure of fertilization is one of them. In traditional IVF 50-60% fertilization is considered normal whereas in ICSI we can achieve up to 90% of success. Few causes may be
Problem in sperm health:
Smoking, diabetes and certain medical conditions directly affect sperm quality. Drugs taken for medical conditions also harm the motility and morphology of sperm.
Female egg issues:
Less number of eggs or low quality eggs often lands in fertilization failure. Women with advanced age who have chromosomal alteration may have this problem. Conditions like endometriosis also lead to poor egg quality and most likely to fail in fertilizing.
Procedural defects:
Sperm count is a major determinant for success in traditional IVF. Improper selection of cases can lead to failure in creating embryos. The culture, media quality and culture condition of the laboratory also matters. Inadequate experience in performing ICSI procedure also fails to yield embryos.
As you can assume, the consequences are usually very traumatic for the couple. In cases of fertilization failure, a thorough review of the couple’s case must be carried out. This is mandatory before considering a new cycle of fertility treatment. In short, it is the only way to arrive at valid conclusions and determine the next steps. In order to reduce the future mishaps you should discuss all the probabilities with your specialist.
Fertilization Failure Or Poor Fertilization Rates After IVF With Traditional Insemination
At times, poor fertilization rates following traditional IVF can happen even without a major issue. Your doctor may suggest to carry out a new cycle using the ICSI technique to fertilize eggs. This change usually causes fertilization rates to improve considerably. However, fertilization failure still can happen in up to 3.6% of cases even when the ICSI technique is used. Women with PCOS or unexplained fertility may have a thick covering around the egg which prevents sperm to get inside. These women benefit from ICSI technique.
Can fertilization fail in ICSI cycle?
Women with failure to fertilise eggs may have negative results in ICSI cycle as well. Furthermore, the implantation and pregnancy rates are lower in patients who have experienced fertilization failure in traditional IVF cycles. This may be due to the fact that there is a high chance of defective embryo development. Chromosome defects during the ICSI cycle causes implantation failure in those who failed in conventional IVF cycle.
Severe male factor infertility
In cases of severe male factor infertility, poor sperm quality might lead to fertilization failure after ICSI. A second sperm sample will be required if the first one contains only immotile sperm. A testicular biopsy may be necessary if second sample is the same as those of the first.
ICSI cases with severe teratozoospermia samples are the subject of intense debate. The forms of sperm and success rates have not been linked in recent research. In patients with repeated fertilization failure following ICSI, switching to donor sperm should be considered.
What is next in male factor infertility?
It is of the greatest priority to establish the cause of the couple’s infertility before a treatment cycle using ICSI. A semen analysis with a normal result does not guarantee the absence of irregularities. The chromosomal makeup of the sperm may be defective in 27% of patients with long-term infertility. In such situations, it is recommended to begin performing more in-depth sperm analyses. These include sperm DNA fragmentation and sperm FISH, which analyze the chromosomes in the sperm. It is also recommended to run meiosis studies on testicular tissue in these patients. It may reveal abnormalities in testicular tissue that are related to repeated IVF failure, fertilization failure and poor embryo quality.
Fertilization Failure Due To Egg Factor Infertility
Fertilization failure, in many situations, can also be attributed to poor egg quality due to advanced female age. Inappropriate ovarian stimulation or low ovarian reserve yields few eggs. In these situations, it is recommended to start a fresh cycle of natural insemination. As a last option, your doctor may suggest to use donor eggs. Approximately 2% of IVF cases with healthy sperm and a good number of eggs can also be unsuccessful in fertilization. In these situations, we might suspect a failure in oocyte activation.
What is failure of oocyte activation and how to deal with it?
Oocyte activation failure has a number of potential causes. The precise cause is not always known and, more critically, is not always curable. Sometimes the explanation may be poor egg quality (morphological defects) related to patient age. It may be the result of incomplete cytoplasmic maturation or an inability of the egg to recognize the sperm. In these situations, we might suspect a failure in oocyte activation.
Currently, there are a number of strategies that can be used to address the problem of oocyte activation failure. Oocyte activation using calcium ionophore is the method that is most frequently used. By using this method, the eggs are brought into contact with a liquid that is rich in calcium ionophore. This initiates the series of events necessary for the egg to start fertilizing properly. In rare situations, the outcomes of this procedure may lead to higher rates of fertilization than in previous cycles.
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