Piezo-ICSI: A Gentler Injection Technique to Help Protect Egg Health and Support Fertilization
Learn how Piezo-ICSI may gently improve fertilization and egg survival during IVF, especially for certain patient groups.
In short: Piezo-ICSI is an advanced form of ICSI that uses fine piezoelectric vibrations instead of the usual sharp needle to enter the egg. In small studies the fertilisation rate rose to 80.5% compared with 65.8% with the conventional method, and egg damage fell from 8.6% to 4.4%, with no clear difference so far in pregnancy or birth rates. It is of most use for women over 35, those with 6 eggs or fewer, and repeated fertilisation failure.
What Is Piezo-ICSI?
Piezo-ICSI is a refined version of the standard ICSI (Intracytoplasmic Sperm Injection) technique, originally developed in Japan to help protect eggs with more delicate membranes. Instead of using a sharp needle to pierce the egg, this method uses a special device called a piezoelectric actuator (PMM4G). This device sends very precise, high-frequency micro-vibrations through a flat-tipped micropipette (about 6 micrometers wide) to gently create an opening in the egg’s outer layers, with minimal disturbance to its natural shape.
How Is Piezo-ICSI Different From Conventional ICSI?
- How the membrane is opened: Traditional ICSI often requires drawing a small amount of the egg’s inner fluid into the needle to help break through the membrane. Piezo-ICSI avoids this step entirely, using gentle vibration pulses instead.
- Needle design: Conventional ICSI uses a sharp, pointed needle that cuts through the egg. Piezo-ICSI uses a flat, blunt-tipped pipette that “drills” through with micro-vibrations rather than cutting.
- Effect on the egg’s shape: Traditional needles can cause more visible deformation of the egg and may shift internal structures. Piezo-ICSI is designed to help the egg keep its natural round shape during the process.
What Do the Clinical Studies Show?
The available research includes data from 69 patients undergoing microinjection, 947 mature eggs, and 137 women studied using a sibling-egg design (comparing eggs from the same patient side by side).
Fertilization Rates and Egg Health
| Measured Outcome | Conventional ICSI | Piezo-ICSI | Statistical Significance |
|---|---|---|---|
| Normal fertilization rate (2PN) | 65.8% ± 2.3% / 70.1% | 80.5% ± 2.4% / 75.4% | P < 0.0001 / P = 0.008 |
| Egg degeneration rate | 8.6% ± 1.2% / 6.4% | 4.4% ± 1.3% / 0.0% | P = 0.019 / P = 0.0446 |
| Abnormal fertilization (1PN + 3PN) | 7.4% ± 1.1% | 2.9% ± 1.1% | P = 0.003 |
| Egg survival after injection | 94.3% | 95.2% | Not statistically significant |
Embryo Development and Quality
| Group | Blastocyst Formation (Day 5–6) | High-Grade Blastocysts (A+B) | Average Usable Embryos per Cycle |
|---|---|---|---|
| All age groups | 54.9% vs 50.2% | 33.3% vs 27.5% (P = 0.019) | 3.8 ± 0.2 vs 3.1 ± 0.2 (P = 0.038) |
| Women over 35 | 52.4% vs 39.6% (P = 0.016) | Notable improvement | About one additional usable embryo per cycle |
| Women 35 and under | 58.3% vs 61.7% | No significant difference | No significant difference |
Pregnancy and Live Birth Outcomes
- Clinical pregnancy rates per fresh embryo transfer were similar between the two methods (57.1% with Piezo-ICSI vs 60.0% with conventional ICSI); researchers note the studies may not have had enough participants to detect small differences.
- Embryo grade strongly relates to implantation potential: Grade A embryos showed around 77% implantation, Grade B around 44%, and Grade C around 20%.
- The main advantage seen with Piezo-ICSI so far is a higher number of good-quality embryos available for freezing, which may help improve overall chances of pregnancy across multiple embryo transfers over time.
Who May Benefit Most From Piezo-ICSI?
Looking at the subgroup results from these studies, certain patients appeared to benefit more than others:
- Women aged 35 and above: This group showed the clearest improvements in both fertilization (P = 0.008) and blastocyst development (P = 0.016). In women 38 and older, egg degeneration dropped to 0.0%, compared to 6.4% with conventional ICSI.
- Patients with a history of lower response to conventional ICSI: Including those with previous fertilization rates below 50% or embryo usability below 20%.
- Patients with fewer eggs retrieved: When six or fewer mature eggs are collected, reducing egg loss (from about 12.1% to 6.3% in this scenario) can make a meaningful difference to the final outcome.
- Patients with previous fertilization difficulties: Eggs with more fragile membranes that didn’t respond well to standard sharp-needle ICSI may respond better to the gentler micro-vibration approach.
In women 35 and younger with typically more resilient eggs, the studies did not find a significant difference between the two techniques.
Why Might Piezo-ICSI Cause Less Damage to Eggs?
- No need to draw fluid from inside the egg: This step in conventional ICSI can disturb the egg’s internal structures, including the spindle involved in genetic material. Piezo-ICSI avoids this by using vibration instead.
- Less mechanical stress on the egg: Sharp needles can twist and pull at the membrane, which may affect the egg’s internal balance. The gentle drilling motion of Piezo-ICSI is designed to preserve the egg’s natural round shape.
- A smaller, more precise opening: The flat pipette tip creates a clean, small opening rather than an irregular tear, which may reduce overall stress on the egg.
Things to Keep in Mind About Piezo-ICSI
- Specialized equipment is required: This includes the Piezo PMM4G system and ultra-fine PINU06-20FT pipettes, along with embryologists specifically trained in the technique.
- Live birth rates per transfer: Current studies have not shown a proven statistically significant difference compared to conventional ICSI. The clearest benefit so far is a greater number of usable embryos.
- Long-term data is still developing: Researchers continue to gather information on cumulative pregnancy outcomes across multiple treatment cycles.
- Limited availability: Piezo-ICSI is not yet offered at every fertility center and may only be available at select clinics.
In Summary
Piezo-ICSI is a mechanically gentler way to perform sperm injection during IVF. Current research suggests it may help improve fertilization rates, reduce egg loss, and increase the number of high-quality embryos available — particularly for women over 35, patients with a history of lower response to standard ICSI, and those with fewer eggs retrieved. For younger patients with generally resilient eggs, outcomes tend to be similar between the two techniques.
If you’re exploring your IVF options and wondering whether Piezo-ICSI might be relevant to your situation, we invite you to discuss it with Dr. Najeeb Layyous, who can help review your individual case and explain what may be most suitable for you.
Dr Najeeb Layyous F.R.C.O.G
Consultant Obstetrician, Gynecologist and Infertility Specialist
The finest doctor in Jordan — may God bless him and his whole medical team. A doctor in every sense of the word. I advise anyone planning a pregnancy to visit Dr. Najeeb Layyous. His manner is wonderful, always smiling, with the highest ethics; he gives every patient her due, and the patient’s comfort matters most to him. We had been to many doctors and none understood and treated my case except him. Special thanks to him and the whole team, and to Dina in particular — a lovely person. I recommend anyone considering IVF or pregnancy to visit his clinic.