What Does Intracytoplasmic Sperm Injection Change in Embryonic Development? The Spermatozoon Contribution

Abstract

The intracytoplasmic sperm injection (ICSI) technique was invented to solve severe male infertility due to altered sperm parameters. Nowadays, it is applied worldwide for the treatment of couple infertility. ICSI is performed with any available spermatozoon from surgery or ejaculated samples, whatever are the sperm motility, morphology or quantity. The aim of the present review was to study if embryo development and kinetics would be modified by (1) ICSI under the technical aspects, (2) the micro-injected spermatozoa in connection with male infertility. From published data, it can be seen that ICSI anticipates the zygote kinetics Furthermore, because fertilization rate is higher in ICSI compared to conventional in vitro fertilization (IVF), more blastocysts are obtained for clinical use in ICSI. Sperm and spermatozoa characteristics, such as sperm parameters, morphology and vitality, DNA content (levels of sperm DNA fragmentation, microdeletions, and chromosomal abnormalities), RNA content, epigenetics, and sperm recovery site (testicular, epididymis, and ejaculated), have an impact on fertilization and blastocyst rates and embryo kinetics in different ways. Even though ICSI is the most common solution to solve couples’ infertility, the causes of male infertility are crucial in building a competent spermatozoa that will contribute to normal embryonic development and healthy offspring.

Low human sperm motility coexists with sperm nuclear DNA damage and oxidative stress in semen

“…Consequently, sperm motility and vitality and sperm fertilizing capability can be limited under both natural and medically assisted reproduction conditions. It should be emphasised that intracytoplasmic sperm injection (ICSI) is the chosen treatment method in cases of asthenozoospermia 121–124 …”

“…It should be emphasised that intracytoplasmic sperm injection (ICSI) is the chosen treatment method in cases of asthenozoospermia. [121][122][123][124] Taking into consideration the above data, the evaluation of SDF and oxidation-reduction potential in semen is a valuable diagnostic and prognostic tool in cases of patients with poor sperm motility. It should be highlighted that depending on the obtained data (confirmed OS in semen), the antioxidant therapy can be suggested to improve sperm quality and function by reducing the pathological action of ROS.…”

Fertility treatment-induced oxidative stress and reproductive disorders

“…In vitro embryonic development in IVF-fertilized oocytes and ICSI-fertilized oocytes is comparable, with the two pronuclei emerging and disappearing at the zygote stage. 159 The efficacy of ICSI is contingent upon several circumstances, including the age of the individuals involved, the calibre of the eggs and sperm used, and the proficiency of the embryologist executing the technique.…”