Thawing sperm and testing its motility

A woman asked on the discussion board: “Does anyone know how important it is that you have a doctor who is experienced in handling frozen sperm and the cryopack, and warming the little guys up? My first two attempts were the first two times my clinic has ever handled frozen sperm, in our little town of 9,000 people. My doctor has the vials in a water bath with a soup bowl and a mug from the staff kitchen at the clinic.”

She continued: “Seems primitive, but they defrost well enough for us to see them swimming under the microscope before she puts them in the syringe. But I’m wondering if the motility is affected or if the number is reduced if she is not handling them properly? Should I be going to a clinic in the city three hours away who my sperm bank say have experience? How much of an issue is this? I don’t want to waste another cycle on this clinic if I will be better off with more experienced “handlers.”

Note: this article, and more, appears in the 37-page 2015 Choice Mom E-Guide: About Sperm as well as the E-Guide: Home Insemination

I asked Dr. Charles Sims, of California Cryobank, to respond to the questions of thawing sperm and testing its motility:

“There are several issues raised.

1. Is proper handling of cryo-preserved sperm important? Yes. The thawing method described may seem primitive because of the use of a soup bowl or coffee mug, but in principle it should work just as well as using a medical laboratory water bath or heat block.

2. Frozen sperm need is to kept at liquid nitrogen temperatures until it is ready to be thawed and used. Excessive exposure to room temperatures in transferring the specimens is the most common risk. In my experience this is more commonly seen in doctors’ offices where the laboratory personnel are not properly supervised or trained.

3. Good technique is very important for proper estimation of percent motility but if the specimen is simply thawed and used for insemination it has no effect on the sperm themselves. In most cases far too much emphasis is placed on trying to perform counts and motility in the clinics laboratories. Variations of 30-40% is common from one lab tech to another. In most cases these clinics would better serve their patients by simply performing a simple thaw and insemination instead of trying to second guess the sperm banks.

4. So in summary, there was nothing wrong with this small town doctor’s technique of thawing the sperm so long as it was promptly used for insemination.

5. The most critical issue is to accurately time ovulation. Being a day early probably does no harm but if the one fertile day of the cycle is missed it doesn’t matter what the technique is or how many motile sperm was used in the insemination.

6. All of these remarks about expertise pertain to cervical insemination. Intrauterine insemination does require expertise in technique. For that the big city experts would probably have better training and have better technical skills.

Charles Sims, MD


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