Polscope可偵測避免ICSI傷害紡錘體

   

Polscope: 

1. 原本使用於複製動物上，可偵測紡錘體位置 藉以去除卵子細胞核及染色體

2. 傳統精蟲顯微注射(ICSI)是根據極體(polar body,PN)判斷紡錘體可能位置

3. 研究顯示 高達2/3的紡錘體並不緊臨PN

4. 使用Polscope可偵測出紡錘體位置 避免ICSI過程傷害卵子紡錘體

5. 使用Polscope可提高受孕胚胎之品質達1/3以上

http://www.nextgenfertility.com.au/index.php/assisted-fertility/the-treatments/polscope

PolScope

PolScope technology combines innovations in polarisation optics (special lighting and lenses) with novel image-processing software and is used as an add-on technique for the ICSI procedure. When performing ICSI the embryologist holds the egg in place with a thin pipette (similar to a tiny, glass straw). The egg is aligned with the polar body at 12 o’clock. The polar body is the left-over chromosomes (bundles of genes) that have been released from the egg. The polar body is placed at 12 o’clock so that damage to the spindle (the site of the egg's genes) is minimised. It is done like this as traditional information has suggested that the spindle lies immediately below the polar body. An injection needle is used to pierce the zona pellucida (egg shell) and inject the sperm (figure 1). The embryologist then carefully withdraws the needle, leaving the sperm inside the egg. In less than a minute, the zona closes naturally and the egg retains its normal shape. Whilst ICSI provides substantial benefit, there are some risks associated with it. The egg can be damaged during the process and the zona can be difficult to pierce.
So what is the advantage to using PolScope technology? Use of the polscope has shown that the spindle does not necessarily lie near the polar body. In up to 2/3 of cases, the spindle is not related to the polar body and therefore that spindle may be damaged by the injection needle during the ICSI process. Disruption of the spindle may affect fertilisation and how the embryo divides. Use of the polscope allows Next Generation Fertility embryologists to align the spindle to 12 o’clock, prior to injection of the sperm, avoiding damage to the egg's genes. It also allows them to identify eggs without spindles, increasing the information available to the patient and their doctor regarding the quality of the eggs produced.
Using the PolScope appears to have a significant effect on the quality of embryos produced during a cycle. Fragmentation of embryos is where there is the appearance of embryo cells falling apart. It is a bad sign and it is also associated with a lower pregnancy rate. It is seen in around 50% of embryos produced using the ICSI process. With the use of the polscope, the amount of fragmentation is reduced to around 1/3 of embryos generated. Overall this appears to increase the number of quality embryos suitable for use (transfer or cryopreservation). The technique is difficult and time consuming for the embryologists involved however may provide significant advantages for patients undergoing ART.