Sperm Tracking and Recovery (STAR)

The Challenge

Male factor accounts for up to 40% of infertility, and in azoospermia the ejaculate contains no sperm detectable by standard examination. Sperm are the smallest cell in the body, and a sample can appear normal while hiding only a handful among millions of other cells and debris.

For many couples, that has meant years of invasive procedures, repeated IVF cycles, and — too often — advice to consider donor sperm or adoption. STAR exists to look again, more closely than possible with the human eye.

What Is STAR?

STAR (Sperm Tracking and Recovery) is a technology developed at the Columbia University Fertility Center. It pairs high-speed imaging with an artificial-intelligence detection model to examine a semen sample far more thoroughly than manual review allows.

When the system identifies a sperm, a gentle microfluidic mechanism isolates and recovers it into a tiny volume of fluid — carefully enough that recovered sperm may be used to fertilize an egg. Any sperm recovered can be used immediately to fertilize eggs, or frozen for future use.

In one validation sample, embryologists searched for two days and found nothing. STAR found 44 sperm in about an hour.

It is like finding a needle hidden within a thousand haystacks — but doing it in just a couple of hours, and so gently that the sperm we recover can be used to fertilize an egg.

What the Process Looks Like

For you, the experience is very similar to a standard semen analysis — no additional procedures required.

1. Confirm eligibility: Contact us to see if you are eligible. Our team reviews to confirm STAR is appropriate for you.
2. Provide a sample: Pick up an at-home collection kit from any of our offices and drop the sample off at your scheduled appointment at 5 Columbus Circle. On-site production is also available if preferred.
3. Same-day results: Turnaround depends on sample volume, but most patients receive results later the same day. Any sperm recovered can be frozen for future use.
4. Plan next steps together: A consultation isn't required beforehand — but if you'd like a full fertility consultation, or to meet our urology team, we're glad to arrange either.

What to Expect

These cases represent some of the most challenging forms of male-factor infertility. We want you to have a clear, realistic picture before you decide. Based on our experience to date:

• ~28% of patients with a prior azoospermia diagnosis have sperm found by STAR
• ~20% of mature eggs fertilize with STAR-recovered sperm
• ~18% of fertilized eggs develop into good-quality embryos for transfer or freezing

These rates are lower than typical IVF/ICSI, but are consistent with expectations given the severity of the underlying condition.

What This Means

• Sperm may not be identified in every case.
• The sperm found are often few, and may be non-motile or abnormally shaped — quality matters as much as number.
• Fertilization and embryo development rates are lower than in standard IVF/ICSI.
• More than one treatment attempt may be needed to achieve a successful outcome.

STAR offers a meaningful opportunity for patients who were previously told they had no sperm and no options — but realistic expectations are essential, and your care team is here to guide you at every step.

How It Works

Detection, Frame by Frame

This image shows STAR identifying a single sperm.

Each blue box is the model identifying the same sperm across consecutive frames, with a confidence score for every frame. A detection is confirmed only when the frames agree — the temporal-consistency check that tells a real sperm apart from debris.

A First in Reproductive Medicine

STAR achieved its first reported pregnancy in March 2025.

After nearly two decades of trying and repeated unsuccessful cycles, one couple became the first to achieve a pregnancy and healthy delivery using sperm identified and recovered by STAR — sperm that conventional examination of the same sample could not find.

This is a single, early case, and it is not a promise of the same outcome for everyone. But it marks a real step: a path where, until recently, there was none.

Recognition and Press

• TIME: Best Inventions 2025
• Newsweek: No. 1 Fertility Clinic in America (2025 & 2026)
• Featured in: TIME, BBC, The Lancet, Columbia

Frequently Asked Questions