Microinsemination — ICSI

Microinsemination, known internationally as ICSI by the term Intracytoplasmic Sperm Injection, is one of the most important techniques of modern assisted reproduction. It is applied in the context of IVF and has offered solutions to couples who face complex fertility problems, especially when there is a serious male factor or failure to fertilize, while no cause can be detected for it to correct it.

The technique is based on the direct injection of a single sperm into a mature egg. In this way, some of the natural stages of fertilization are bypassed, such as the spontaneous penetration of the sperm into the egg, which in some cases cannot be carried out normally.

Microinsemination has significantly expanded the possibilities of reproductive medicine, offering perspective to cases where in the past achieving pregnancy was considered particularly difficult or even impossible.

However, like any method of assisted reproduction, it requires proper indication, specialized design, proper training and extensive technical experience as well as realistic information of the couple.

What is Microinsemination?

the microfertilization It is a laboratory technique in which the embryologist chooses a sperm and injects it directly into the interior of a mature egg, with the help of a special high-resolution microscope and micromanipulation tools.

Unlike conventional IVF, where the sperm are placed together with the eggs and the fertilization is done more "naturally" in the laboratory, in ICSI the process is completely targeted. Each mature egg is fertilized by the direct introduction of a selected sperm.

This method is particularly useful when the number, motility or morphology of spermatozoa does not allow fertilization in a conventional way. In the event that the characteristics of the sperm are satisfactory, the choice of spermatozoa in relation to morphology and motility, with the help of strong microscopes, increases the probability of success.

In Which cases Is microinsemination indicated?

Microinsemination is mainly recommended in cases where there is a serious male infertility factor or when there are indications that conventional IVF may not lead to satisfactory fertilization of the eggs.

ICSI can be recommended in cases such as:

  • oligospermia, when the number of sperm is very low.
  • asthenospermia, when spermatozoa show reduced motility.
  • teratospermia, when a large percentage of sperm show morphological abnormalities.
  • Severe male infertility factor, where natural fertilization or conventional IVF is difficult to achieve.
  • Azoospermia, as in the case where the sperm is surgically taken from the epididymis or testicle.
  • Occlusion of the spermatic tracts, where there are no sperm in ejaculation but can be recovered surgically.
  • High levels of antisperm antibodies, which may affect the ability of sperm to fertilize the egg.
  • Previous Fertilization Failure in an IVF cycle.
  • Low or zero fertilization rate In a previous IVF attempt.
  • Increased fragmentation of sperm DNA, when this is considered important by the specialist and the embryologist in the context of the overall evaluation.

The choice of microinsemination should not be made mechanically, but after a complete assessment of the couple. In some cases it is the most appropriate choice, while in others it can be combined with additional techniques or a different therapeutic design.

How is it carried out?

Microinsemination takes place in the context of an IVF cycle and includes specific stages.

Initially, the woman receives medication to stimulate the ovaries, with the aim of developing more follicles. Ovarian response is closely monitored by ultrasounds and, where appropriate, by hormonal tests.

When the follicles reach the appropriate stage of maturation, the ovulation. During this process, the eggs are collected from the ovaries with ultrasound guidance.

On the same day, a sperm sample is taken from the partner or a properly prepared sample is used. In cases of azoospermia or obstruction, the sperm may be surgically taken from the epididymis or testicle.

The sperm sample is then subjected to a special laboratory treatment to select the most suitable spermatozoa. The embryologist, with the help of a microscope and a special microneedle, injects a sperm into each mature egg.

Fertilized eggs are monitored in the laboratory under controlled conditions. The development of the embryos is evaluated in the following days and, depending on their quality and development, the embryo transfer is planned.

Embryo transfer is usually carried out on the 3rd or 5th day after fertilization, depending on the treatment plan and the embryonic picture.

Which are the advantages of microinsemination?

Microinsemination offers significant advantages, especially in cases where sperm presents serious disorders.

Its main advantage is that a very small number of spermatozoa is required. Even when there is little sperm available, such as in cases of sperm recovery surgery, ICSI can allow fertilization of the eggs.

Also, the technique allows the laboratory to select sperm with better mobility and morphology, increasing the chances of fertilization in cases where conventional IVF may not be sufficient.

Microinsemination is therefore a valuable option for couples with a serious male factor, a previous failure to fertilize or the need to use surgically recovered sperm.

chances of success of microinsemination

The success rates of microinsemination depend on many factors and are not the same for all couples.

Egg fertilization with ICSI can be achieved at high rates, often about 65% to 75% of mature eggs, when there are appropriate conditions. However, the fertilization rate is not necessarily identical to the pregnancy or birth rate of a child.

The final success of a cycle depends on factors such as:

  • the woman's age,
  • the quality of the eggs,
  • Manipulation of preparation before ovulation to obtain mature eggs
  • The greater number of eggs that can be taken for the woman's data to increase the statistical fate of the project
  • the quality of the sperm,
  • Response to drug stimulation,
  • The quality of the embryos
  • the condition of the uterus and endometrium,
  • Design, experience and attention during embryo transfer
  • history of previous attempts,
  • The cause of infertility.

For this reason, each couple should be informed individually. The responsible medical approach is not based on general promises, but on a realistic assessment of the data of each incident.

Microfertilization and male infertility

ICSI is one of the most important developments in the treatment of male infertility. In cases where sperm presents serious problems with numbers, motility or morphology, microinsemination can give the possibility of fertilization which would otherwise be extremely difficult.

It is also of particular importance in cases of azoospermia, where there are no sperm in the ejaculation, but they can be recovered surgically from the testicle or epididymis. In these cases, ICSI is usually the method that allows the use of even a very small number of sperm.

The successful treatment of such cases requires proper cooperation between reproductive specialist, urologist/andrologist and embryological laboratory. The design should be careful, especially when the available sperm is limited or taken with surgical recovery.

Ioannis A. Sklavounos MD MSC DFFP
Obstetrician Surgeon Gynecologist
Specialists & Retrained in Great Britain
T.Senior Clinical Fellow – Liverpool Woman’s Hospital UK

IVF

Bibliography

American Society for Reproductive Medicine — ASRM.

Intracytoplasmic sperm injection — icsi for non–male factor indications: a committee opinion.

Fertility and Sterility, 2020.

American Urological Association — AUA / American Society for Reproductive Medicine — ASRM.

Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline.

European Society of Human Reproduction and Embryology — Eshre.

What is icsi?

European Society of Human Reproduction and Embryology — Eshre.

Guidelines, Consensus Documents and Recommendations.

National Institute for Health and Care Excellence — Nice.

Fertility Problems: Assessment and Treatment.

National Institute for Health and Care Excellence — Nice.

Management of Male Factor Fertility Problems.

Efficacy of intracytoplasmic sperm injection in women with non-male factor infertility: A systematic review and meta-analysis.

Reproductive Biology and Endocrinology, 2023.

Zegers-Hochschild, F., Adamson, G. D., Dyer, S., et al.

The International Glossary on Infertility and Fertility Care, 2017.

Fertility and Sterility, 2017.

World Health Organization — Who.

Who Laboratory Manual for the Examination and Processing of Human Semen.

Palermo, G., Joris, H., Devroey, P., Van Steirteghem, A. c.

Pregnancies after intracytoplasmic injection of single spermozoon into an oocyte.

The Lancet, 1992.

Book an Appointment