• Specimen Quality Standards

    How Many Sperm Are In A Vial?

    People often have questions about how many sperm should be in a vial and how this count is determined. Here’s some information to clarify these issues.

    Before contemplating the number of sperm in a vial, it’s important to keep in mind that numerous studies find that pregnancy rates with intrauterine insemination are maximized with 5 million total motile sperm. In other words, 5 million and 50 million motile sperm offer the same chance of success. California Cryobank established vial standards to well-exceed the number of sperm required to achieve pregnancy.

    The CCB vial standards refer to the total motile sperm. The total motile count is calculated by multiplying the percentage of motile sperm by the number of all sperm counted. A standard ICI vial contains a minimum of 15 million total motile sperm after it’s been thawed, prior to washing. A standard IUI vial contains a minimum of 10 million total motile sperm after it’s been thawed, with no wash necessary. We perform a post-thaw count on one vial from every lot to confirm the sperm survive the freezing process and still meet our high standards.

    Sperm are living, moving cells, and under the best of circumstances the calculation of total motile sperm count can vary by 20%. When vials are evaluated in a doctor’s office, additional variables, such as amount of time the specimen is thawed, the individual doing the counting, and the type of counting chamber used, can significantly affect the total motile sperm concentration result. CCB uses a device called a Makler chamber to count sperm under a microscope. This counting chamber has a large depth of field that allows technicians to evaluate a three-dimensional drop of sperm. Many clinics use a system that relies on disposable slides. Disposable chambers sandwich a drop of the specimen between two slides, pushing much of liquid to the edges. While these slides are a perfectly acceptable means for evaluating a sperm sample, they are known to produce counts that are 30% lower than those derived from the Makler. One must take into consideration an adjustment for this difference when comparing calculations based on the disposable slides to those produced using a Makler chamber.

    Occasionally physician's laboratories factor sample volume into their assessment of vial contents. Our laboratory uses calibrated instruments to precisely deliver the exact volume of sample in every vial. All IUI vials contain .5 ml and ICI vials contain 1 ml. Other laboratories use a variety of different means to recover the specimen. Their measurement of recovery volume is often an estimation and should not be factored into the determination of total motile sperm count in a vial.

    Normal motility for a once frozen sperm sample is any fraction above 20%. Once thawed, sperm takes some time to "wake up" and start moving again. As a result, motility actually increases after insemination as more sperm adjust to the ideal 98.6-degree environment. It is preferable to have sperm under-thawed prior to insemination. If they are over-warmed, they are more likely to die quickly. Most specimens that appear to show poor motility immediately after thaw are actually ideal once used for insemination.

    Specimen Quality Standards  

    California Cryobank is committed to providing donor semen specimens of the highest quality. The Cryobank evaluates each specimen prior to release to ensure that it meets our high quality standards. A post thaw analysis of sperm count and motility is included with every donor specimen shipment. IUI specimens are processed and ready for intrauterine insemination.

    Premium vials


    Motile Sperm/Vial (after thawing)*

    • Intracervical Insemination (ICI)
    • Intrauterine Insemination (IUI)
    • A minimum of 15 million
    • A minimum of 10 million

    A.R.T. Vials


    Motile Sperm/Vial (after thawing)*

    • Intracervical Insemination (ICI)
    • Intrauterine Insemination (IUI)
    • 8 - 14 million
    • 5 - 9 million

    *Variation in sperm counting can range 15 - 30% based on different laboratories, individual medical personnel and counting methods. It is possible that the values obtained by your lab will be less than our guaranteed standard minimum. This does not necessarily indicate that the specimen is substandard. The Cryobank makes allowances for analytical variations when determining if the specimen is eligible for credit.

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