Evaluation of the Oocyte Morphology and Quality as a Key Performance Indicator during ICSI.

When I started performing Icsi, the painstaking growth was incorporated more in sperm immobilization. ‘Sperm catching’ as it is termed more in layman terms needs rigorous practice and assumes importance because you are going to choose a dozen sperm out of a million to inject a dozen Oocytes. Your eyes are going to replace natural selection and this will place enormous responsibility on your shoulders. Oocyte injection technically is mechanical and barring that innate nervousness initially in handling them, the procedure is not as skillfully significant as sperm immobilization. Although suction pressure you apply and the amount of cytoplasm you aspirate has an impact and can be mentioned in the skill bandwagon, they too become reflex actions as you progress to do more cases.

There is a fundamental factor in oocyte injections which is ignored considerably and predominantly in a batch system. Oocyte injections during ICSI may be about skills but equally essential is your observations about oocyte morphology and quality. The documentation of the same plays a critical role in analyzing results and coming to fruitful conclusions. In the case of oocyte injection, observing the oocyte for its abnormalities, resistance, and quality, in particular, can have profound consequences. For example, let us talk about abnormalities. A human mature oocyte has components such as zona pellicuda, the perivitelline space, cytoplasm, and the polar body. Whilst injecting oocytes, recording sub-optimal structures can help us in connecting it to outcomes thereafter. Oocyte morphology related to cytoplasm has more impact than the say zona pellicuda. Sometimes, visible structures in the oocyte in the form of central dark granulations do have effects like poor blastomere survival after vitrification. Then there are other abnormalities like refractile bodies inside the cytoplasm which have no documented significance but from my experience, observation of these structures has resulted in less fertilization rate. There may or may not be a correlation but writing down all these occurrences helps in analyzing better and in cases of surprises like poor fertilization. This information needs to be shared with the clinician not just from the scientific point of view but also for determining the next course of the said IVF cycle. In a tendency to just reply ‘oocytes were good’ without any documentation or observations giving us less fertilization rate the next day will only increase doubts and decrease the trust factor.  Depending upon the severity of the abnormality, it is essential to make the clinician aware of the same. In one particular case, I happened to record huge vacuoles in all the oocytes of a patient. I apprised the clinician about it and predictably the next day, very few oocytes progressed and many even degenerated. Sometimes, abnormalities can be too bad to not even proceed with the injections as it may have serious outcomes.

Read more on The importance of embryo grading and selection

Along with the said abnormalities, the other aspect lies in documenting the oocyte quality in terms of its resistance. When we are injecting a sperm inside an oocyte, it will naturally provide resistance and in the advent of the same show a conical funnel-like structure. Before depositing the sperm in the cytoplasm, we tend to draw the cytoplasmic contents which will gradually flow in the injecting pipette. The moment plasma membrane breaks, the flow into the injecting pipette will pick up speed and then we have to stop and deposit the sperm inside. This process will give us an idea about the resistance of the oocyte and the quality too. A funnel shape along with the extent up to which we can draw the cytoplasmic fluid will give us the information about the resistance. If no funnel is formed and the resistance is zero, the oocyte has the possibility of degenerating which can happen at one of the two times. A poor resistance oocyte can degenerate immediately as you observe it when you keep the oocytes back to incubator post injections. Oocytes can also degenerate later when we check them for fertilization the next morning and find about it. This information about poor resistance has to be given to the clinician as a high degeneration rate can raise eyebrows and create unnecessary doubts about your ICSI technique.

The last critical part of an oocyte injection during ICSI is the number of sperm you take in the injecting at a time. Taking multiple sperm can result in polyspermy, abnormal fertilization, and subsequent abnormal embryo. How much ever proficient and good you may be at ICSI, risk will always be prevalent in case you aspirate multiple sperm. If by mistake you deposit two sperm in an oocyte, you have to discard the same and maybe that particular one may have given you a pregnancy. Further to that, never take more than ten oocytes at a time in an ICSI dish when you are doing ICSI. In case you happen to have a PCOS patient with 30 oocytes, inject them in batches of ten rather taking all of them together. Overexposure of oocytes is detrimental and more possibility is about injecting the same oocyte twice to incite a disaster.

Read More On IVF Lab — Tips and tricks: Beyond the obvious!

Oocyte injection is not a mechanical process. It is documenting and mechanical where the injecting part has to be supported by timely observations. In an ‘in house’ set up, observations can be better recorded but it’s not impossible either in a freelancing situation. Good Lab Practices are paramount to a terrific IVF laboratory and not just the success rates. The way fertilization rates and BHCG is superseding implantation and take-home baby rates, evaluation of oocytes during ICSI is buried under the weight of how quickly you do oocyte injections. Speed is important but so is your observation!

We are here to help you with everything in IVF

• IVF Equipment
• IVF Turnkey Projects
• IVF Consumables
• IVF Training
• IVF Quality Control