PICSI – physiological ICSI.
In sperm selection with PICSI ("physiological ICSI") we use hyaluronic acid to distinguish immature from mature sperm – identifying higher-quality sperm for the subsequent ICSI.
What is PICSI and how does it help?
In sperm selection with PICSI ("physiological ICSI") we use hyaluronic acid to separate immature from mature sperm. This appears to identify sperm of higher quality for the subsequent ICSI.
PICSI is not a treatment of its own, but an additional step in the laboratory – a selection procedure carried out before the ICSI. For you as a couple, nothing changes about the procedure: stimulation, egg retrieval, embryo transfer and implantation phase remain unchanged. The difference arises exclusively under the microscope, at the moment when it is decided which single sperm is placed into the egg.
How sperm selection with hyaluronic acid works.
How it works
The heads of mature sperm carry a specific sensor (receptor) for hyaluronic acid (hyaluronan). Hyaluronan is an essential component of the shell surrounding the egg. Immature sperm do not have this receptor. In the laboratory, PICSI thus allows individual mature sperm to be selected under the microscope, based on their appearance, for the subsequent ICSI.
The advantage
According to studies, a very high percentage of these bound sperm are free of DNA damage. The method therefore appears to lead to higher fertilisation rates.
When we consider a PICSI.
PICSI is an additional procedure that we use in a targeted way – not routinely with every treatment. Whether it makes sense in your situation follows from the semen analysis and from the course of previous treatments.
Typical starting situations
We talk to couples about PICSI above all when
- the semen analysis shows a high proportion of malformed or immature sperm,
- there are indications of increased DNA fragmentation of the sperm,
- in a previous ICSI noticeably few eggs were fertilised or the embryos developed only hesitantly,
- there have been repeated unsuccessful treatment cycles or early miscarriages,
- despite a comprehensive work-up, no clear cause for the involuntary childlessness has been found.
What PICSI requires
For selection to be possible, there must be motile sperm present at all that can bind to the hyaluronic acid. With very severely reduced findings – for example, when only single sperm are found or these come from a testicular biopsy – selection by this principle is not meaningfully possible. In that case, our embryologists select the sperm by motility and morphology under the microscope, if necessary with other procedures. We also discuss this with you beforehand, not only in retrospect.
PICSI step by step in the laboratory.
The selection takes place on the day of egg retrieval and does not prolong your treatment.
Sperm collection and preparation
On the day of egg retrieval, the sperm sample is provided – usually after two to three days of abstinence. In the laboratory it is first prepared as with every ICSI: the vital, motile sperm are separated from seminal fluid and cell debris and concentrated in a culture medium.
The hyaluronic acid dish
Part of the prepared sample is placed into a special dish whose bottom is coated with hyaluronic acid. Hyaluronan is exactly the substance that also occurs in the natural environment of the egg – so the dish imitates a condition that mature sperm respond to in the body.
Binding – the actual selection
Mature sperm carry receptors for hyaluronic acid on their heads and adhere to it. Immature sperm do not possess these receptors and do not bind. This creates a pre-selection that is not based on outward appearance alone, but on a functional property of the sperm.
Selection under the microscope
From the bound sperm, our embryologists select under the microscope those that additionally convince in motility and shape. This step remains manual work and a matter of experience – PICSI does not replace the trained eye, but narrows the choice beforehand to the most promising candidates.
The ICSI
The selected sperm is then placed directly into the egg with a fine hollow needle – the actual ICSI procedure. The next day, it is checked how many eggs actually show signs of successful fertilisation.
Everything else as usual
Embryo culture, embryo transfer and implantation phase then proceed unchanged. Where it makes sense, we combine the transfer with laser-assisted hatching support (assisted hatching). The pregnancy test takes place around two weeks after fertilisation.
Advantages – and what PICSI cannot do.
We consider it part of good counselling to assess additional procedures realistically.
What speaks for PICSI
The selection is gentle and works with a mechanism that the natural path to the egg also uses – hence the name "physiological ICSI". For the patient, nothing changes: no additional medication, no additional appointments, no prolongation of the treatment. The selection concerns exclusively the laboratory step and is therefore an addition without any physical strain. It can also be combined well with the other procedures we use in the laboratory.
Where the limits lie
PICSI improves the selection – it does not improve the sperm themselves. If semen quality is fundamentally reduced, that remains a factor that even selection cannot remove. Nor does PICSI influence egg quality, which depends on the age of the woman and other factors, or implantation in the uterus.
For the effectiveness of sperm selection procedures there are indications from studies, but no guarantee for the individual case. We therefore use PICSI where there is a comprehensible rationale, and not across the board. Before every treatment, we discuss with you what you can expect – and what not.
How PICSI interacts with other methods.
PICSI and ICSI
PICSI or Fertile Chip©?
Both procedures aim to find sperm with DNA as intact as possible – by different routes. PICSI uses binding to hyaluronic acid, while the Fertile Chip© ("Chipsi") imitates the natural migration of the sperm with a microstructure. Which procedure fits better in your case depends on the findings.
Around the embryo transfer
After fertilisation, embryo development and implantation determine the further course. Here, extended culture to the blastocyst stage and – with a hardened outer shell – assisted hatching can be useful additions.
A laboratory that can judge procedures
Sperm selection is laboratory work – and laboratory work lives on experience. The Wunschbaby Institut Feichtinger has been a pioneer of reproductive medicine in Austria since 1982/83: the first Austrian IVF baby was born here, and in 1993 the WIF introduced ICSI in Austria. More than 30,000 births have resulted from treatments with us.
Because we have our genetics and hormone laboratory in-house, we can bring findings, selection procedure and treatment plan directly together – 360 degrees under one roof, at our locations in Vienna, Baden and St. Pölten. And we stick to what we can take responsibility for on your behalf: state of the art where it helps, and honest restraint where an additional procedure brings no benefit.
Frequently asked questions about PICSI.
What exactly does PICSI mean?
PICSI stands for "physiological intracytoplasmic sperm injection". The addition "physiological" refers to the fact that the pre-selection of the sperm imitates one of the body's own mechanisms: the binding of mature sperm to hyaluronic acid, as it also occurs in the environment of the egg. The injection itself corresponds to an ordinary ICSI.
Is PICSI a treatment of its own or an addition to ICSI?
PICSI is an additional step in the laboratory and always part of an ICSI. It does not replace any treatment and changes neither the hormonal stimulation nor the egg retrieval or the embryo transfer for you. The entire difference lies in the way the sperm is selected.
Will I notice anything of PICSI as a patient?
No. The selection takes place exclusively in the laboratory. No additional medication, no additional appointments and no further procedures are needed for it. The duration of the treatment does not change either.
What is the difference between PICSI and the Fertile Chip© ("Chipsi")?
Both procedures select sperm by functional properties, but use different principles for it. With PICSI, mature sperm bind to a hyaluronic acid coating. With the Fertile Chip©, the sperm have to migrate through a microstructure modelled on the natural path to the egg. Which procedure is more suitable is something we decide on the basis of your semen analysis.
Who is PICSI particularly interesting for?
Above all for couples in whom the male factor is in the foreground: a high proportion of immature or malformed sperm, indications of DNA damage, noticeably low fertilisation rates in a previous cycle or repeated unsuccessful treatments. The basis of the decision is always a current semen analysis and the course of earlier cycles.
Does PICSI guarantee a pregnancy?
No, and we would not hold that out in prospect either. PICSI can improve the selection of the sperm, but has no influence on egg quality, embryo development after fertilisation or implantation. It is a building block that can support the chances – not a certainty.
Is PICSI safe for the child?
With PICSI, nothing is altered on the egg or the sperm – it is merely selected which of the existing sperm is used for the injection. No substances foreign to the body are used: hyaluronic acid is a natural component of the environment of the egg.
How do I find out whether PICSI makes sense for me?
In a personal consultation. We look at your semen analysis, the woman's hormone status and – if available – the course of previous treatments, and derive from this whether a selection procedure brings a recognisable advantage. You will find an overview of all methods under fertility treatments.
Is PICSI right for you?
In a personal consultation we will clarify whether sperm selection with PICSI is a useful addition to your treatment.
Or call us: +43 1 877 77 75