All IVF cycles at Bavishi fertility institute are ICSI cycles; this allows our expert embryologists to select the best sperm based on their motility and morphology (structure).
However, sperms that look good under the microscope may have DNA damage or reduced fertilizing capacity. Medical illnesses like diabetes can also reduce the fertilizing capacity of sperm. Patients with suspected or patients who previously show poor fertilization with IVF or ICSI are good candidates for Advanced sperm selection techniques.
Various techniques select sperms based on various functional features such as the ability to connect to oocytes like membranes, apoptotic markers (markers that signal cell death) or a more detailed structure evaluation.
The state of the sperm DNA, the ability of the sperm to connect to oocytes like membranes, the presence in the membrane of certain apoptotic markers and indicators of sperm maturity, and more detailed structural evaluation by IMSI procedure could be used to help identify the best sperm.
The PICSI (Physiological Intracytoplasmic Sperm Injection) technique improves pregnancy rate and reduces the risk of miscarriages. The advantage of this method is the objective selection of spermatozoa based on their functional quality.
What is the principle of the method?
Hyaluronic acid is an important natural part of the eggshell. The head of the mature sperm contains a specific receptor that allows it to bind to hyaluronic acid. This is the process that occurs naturally in nature. Using the PICSI method, therefore, for fertilization, the embryologist chooses the spermatozoa that have a positive bond with the gel containing hyaluronic acid. The selected sperms are used for fertilization using the ICSI method.
Only a mature spermatozoon can have this interaction, which is biochemically competent for binding with hyaluronic acid. Scientific studies have confirmed that spermatozoa that bind to hyaluronic acid have better morphology, a lower percentage of chromosomal abnormalities and better DNA integrity.
When is PICSI recommended?
PICSI is recommended in the following cases:
A high percentage of spermatozoa with fragmented DNA
Woman’s age over 38
In previous failed fertilization cycles using ICSI
IMSI uses specialized lenses and software to magnify the sperm much more than usually used. The large-magnitude morphological selection of sperm allows the selection of the best sperm in real-time and its direct use in ICSI.
As a first step, the primary sperm selection process is done as done for standard ICSI. A few more sperms are selected than required. These sperm are now seen under High magnification, and their structure is carefully studied. Of these, only the structurally normal sperm is selected and used for fertilization with ICSI.
IMSI technique is a subjective analysis; the experience of our expert embryologist play a crucial part in the success.
Magnetic-activated cell sorting (MACS)
The MACS technique separates apoptotic sperm cells from normal sperms. Apoptosis is a process by which a cell destroys itself at the end of its life cycle. In MACS, damaged apoptotic sperm is labelled with magnetic nanoparticles, and then they are put through a column, where the apoptotic sperm is captured.
Intact live sperm flow through the column and are collected to fertilize oocytes.
Recent research data evidence of meta-analysis shows that MACS do not improve embryo implantation.
In nature, sperms travel from the vagina to the fallopian tube to fertilize eggs. While in IVF, they come in contact with female eggs directly. The principle of microfluidics is to create micro-channels that stimulate the female reproductive tract. Sperms that travel through these microchannels are selected for fertilization.
Sperms are highly condensed cells with compact DNA. They exhibit high birefringence when struck with polarized light.
Those with vacuoles do not generate such a refractive index, and those with altered morphology either in the head, intermediate piece, and flagellum. The selected sperms with high birefringence are used for fertilization.
Selection of the genetically normal sperm for fertilization is crucial for optimum success. It is challenging in some cases where judicious use of appropriate technology by experienced embryologists is a blessing.