Oocyte Spindle Assay: Does It Boost Your IVF Results?

Spindle Screening for IVF – Smarter Fertility Treatment for Couples

As an IVF specialist, I am often asked about newer technologies that promise better success rates. One such technique is the Oocyte Spindle Assay (OSA).

While it may sound very advanced, it’s not a new tool. It has been around for a few years, and with recent improvements in imaging and polarising software, we now have better insights into how chromosomes behave inside an Oocyte, or the egg, before fertilisation.

Let’s explore what the Oocyte spindle assay means, when we use it in clinical practice, and whether it truly improves IVF success rates.

The Oocyte Spindle Assay is a technique that helps embryologists visualise the spindle structure inside the egg. The spindle is a microscopic structure that plays a vital role in ensuring chromosomes are aligned correctly before fertilisation.

During ICSI (Intracytoplasmic Sperm Injection), embryologists normally orient the egg so that the polar body is positioned at 6 o’clock or 12 o’clock under the microscope. This technique has been standard for the last 20 years and gives excellent fertilisation rates.

This technique is not required for every IVF patient. We usually suggest it in very specific scenarios:

• Previous fertilisation failure with ICSI
• Low AMH (low ovarian reserve) in the female partner
• History of embryo arrest in previous IVF cycles

This technique of viewing the spindle inside the egg is useful only for couples planning IVF with their own eggs and sperm.

The Oocyte Spindle Assay takes this one step further. Using polarised light, we can see the spindle itself, study its alignment, and then adjust the orientation of the egg accordingly before injecting the sperm.

From our clinical experience:

• It can lead to slightly better fertilisation rates.
• It may result in a higher number of blastocysts.
• However, its direct impact on clinical pregnancy rates remains uncertain.

Many new research papers are exploring AI-driven models for automatic fertilization. Currently, we use the Oocyte Spindle Assay very selectively in our practice. 

When we perform a polarisation study of the egg, we usually combine it with time-lapse monitoring of the embryo. This setup provides an undisturbed culture for five days while also giving us a detailed video of how the embryo grows and passes key fertilization checkpoints.

As a referral fertility center, we see many couples from across India who have already gone through failed fertility treatments elsewhere. Based on our experience, we know that the spindle assay with polarization is not necessary for every woman. We only use it when our protocol shows that it can truly make a difference.

No Extra Cost for Patients

We understand that by the time couples reach us, they have already spent a lot on previous treatments. That’s why, when we decide to use the spindle assay, there is no additional charge for this procedure.

Our Promise of Clarity and Care

By sharing this approach openly, we want couples to feel confident in their treatment journey. Our goal is to give you clear information so you can make the right clinical decisions with complete peace of mind.

With the rise of AI-driven fertilisation models, interest in spindle assessment has grown. Many new papers are being published in this area. However, the real-world benefit for pregnancy rates is still being studied.

At present, Oocyte Spindle Assay is a supportive tool, not a guaranteed solution.

• What is the Oocyte Spindle Assay? A technique to study the egg’s spindle alignment before ICSI.

• Who needs it? Couples with fertilisation failure, low AMH, or embryo arrest.

• Does it improve IVF results? It may enhance fertilisation and blastocyst formation, but there is no proven major benefit on pregnancy rates yet.

• Is it for everyone? No, it is used selectively.

If you’ve faced IVF failures, low egg reserve, or poor embryo development, advanced techniques like Oocyte Spindle Assay and time-lapse culture may help us optimise your chances.

📞 Schedule a consultation with Dr. Jay Mehta and our fertility team today. Let’s discuss whether this technique could support your IVF journey.