New IVF device finds extra eggs in discarded follicular fluid

A 2026 study found that a microfluidic device called FIND-Chip can recover additional eggs from follicular fluid that may have been missed by manual searching after an egg retrieval, with one live birth reported.

In IVF, the number of eggs retrieved matters. More eggs usually means more embryos and a higher chance of success over time.

During the egg retrieval, the doctor aspirates fluid from each follicle into a tube for the embryologist, who pours the fluid into a dish and manually searches for eggs under a microscope.

Follicular fluid can be very messy. It often contains blood cells, clots, tissue fragments, and debris, which can make eggs difficult to see and increases the risk that some are missed.

A new study by Mutlu et al. (2026) developed a microfluidic device called FIND-Chip designed to automate egg isolation and denudation from follicular fluid. The researchers also tested whether it could recover additional eggs from fluid that had already been screened and marked as “discarded.”

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How the FIND-Chip Works

The FIND-Chip is an automated microfluidic system that processes follicular fluid and returns a small droplet containing clean, denuded (stripped) eggs ready for ICSI or freezing.

It works in four main steps and takes about 30 minutes to complete:

• Filter: The follicular fluid is loaded and then first passes through a series of tiny gaps that trap large tissue fragments and clots. Cumulus–oocyte complexes (eggs with cumulus cells still attached) are also held in this area.
• Denude: The sample then moves through narrow channels while hyaluronidase is added to help remove the cumulus cells. The system gently moves the eggs back and forth through these channels, stripping away these cells.
• Concentrate: Most of the excess fluid and small debris, including many red blood cells, are removed through side channels. This reduces the volume and focuses the eggs into a smaller space.
• Capture and release: Denuded eggs are trapped and then released into a small droplet for collection in a dish.

Does FIND-Chip work? From preclinical testing to IVF patients

Before testing the device clinically, the authors validated it in bovine (cow) eggs and donated human eggs:

• They found that FIND-Chip–processed oocytes showed no differences in fertilization or blastocyst development compared with manually denuded oocytes.
• When known human eggs were spiked into follicular fluid, the device recovered 100% of them, and unexpectedly also identified additional eggs that had been missed during manual screening.

They then moved on to testing it clinically in a small pilot study involving discarded follicular fluid from 19 patients:

• At least one extra oocyte was found in 11 of 19 patients (57.9%).
• In total, 23 additional oocytes were recovered from 225 that were originally identified (10.2% increase).
• About 52% of the extra oocytes were mature (MII) and used for ICSI.
• Fertilization, blastocyst formation, and embryo grades were similar.
• One FIND-Chip–processed oocyte resulted in a euploid blastocyst and live birth.

Finally, they examined discarded follicular fluid from 582 patients across four IVF clinics.

• Extra oocytes were recovered in 54.3% of patients, representing 583 additional oocytes that were found.
• About 41% of extra oocytes were mature.
• They found extra eggs across all of the following groups, based on the number of eggs initially retrieved:
  • 0–5 oocytes initially retrieved: Extra oocytes were found in 35.0% of patients.
  • 6–11 oocytes: 51.5%.
  • 12–17 oocytes: 59.5%.
  • 18–24 oocytes: 61.8%.
  • >24 oocytes: 65.6%.
• Extra eggs were found even when embryologists were given the opportunity to double check samples without time limits.
• Only 31.8% of samples were fully processed, meaning the number of missed eggs may be underestimated. They did this so they could test samples from more patients overall.

Conclusion

This study shows that FIND-Chip can recover additional eggs from follicular fluid that may be missed during manual searching.

Across laboratory validation and testing in four IVF clinics, the device consistently identified extra oocytes without clear evidence of harm to fertilization or early embryo development.

Extra oocytes were found in more than half of patients overall. This included patients with very low initial egg numbers (0–5 eggs retrieved), where 35% had additional eggs identified. In one case, a patient who initially retrieved 3 eggs had 5 more eggs recovered using the device.

Many of these additional eggs were mature (MII) and ready for ICSI. One FIND-Chip–processed egg resulted in a euploid blastocyst and live birth, which would have been discarded otherwise.

Besides finding more eggs, the authors note that the device handles eggs more gently and consistently which might translate to better embryo quality and more live births. However, this hasn’t been tested in large clinical trials yet and they estimate this would take several years.

Overall, this study highlights the limitations of manual microscopic searching of follicular fluid and shows that a microfluidic device can increase the number of eggs in an IVF cycle. For more details and to explore the methods more, I encourage you to check out the full study on Nature Medicine (open access), which includes detailed images and technical descriptions.

Reference

Mutlu, B.R., Civale, S.C., Diettrich, J. et al. Microfluidic automation improves oocyte recovery from follicular fluid of patients undergoing in vitro fertilization. Nat Med (2026). https://doi.org/10.1038/s41591-026-04207-x

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About Embryoman

Embryoman (Sean Lauber) is a former embryologist and the founder of Remembryo, an IVF research and fertility education website. After working in an IVF lab in the US, he returned to Canada and now focuses on making fertility research more accessible. He holds a Master’s in Immunology and launched Remembryo in 2018 to help patients and professionals make sense of IVF research. Sean shares weekly study updates on Facebook, Instagram, and Reddit regularly. He also answers questions on Reddit or in his private Facebook group.

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