Some Facts About Sperm Freezing & Insemination
The first successful sperm freezing technique was developed in the 1950s. Researchers learned that sperm could not survive freezing without adding some agents that prevented the cells from rupturing during freezing and thawing. These agents are called "cryoprotectants" and are usually composed of egg yolk, glycerol and some buffers. The cryoprotectant is slowly added to the fresh ejaculate, and the sperm is gradually cooled and then frozen in liquid nitrogen at a temperature of -195 degrees centigrade. It is normal for about half of the sperm cells to die during the freezing and thawing process. Sperm that have robust motility in the fresh ejaculate can usually survive several years when frozen.
It is generally accepted that it takes about 10 to 25 million motile sperm for conception to occur through insemination, though many factors influence whether there is a successful pregnancy. Normally, men produce between 20 million and 200 million sperm per 1 cc (cubic centimeter) with each ejaculation. Illness, stress and other factors can cause a low sperm count and/or motility. Advanced assisted reproductive procedures such as in vitro fertilization (IVF) are available for such cases.
Studies have shown that it takes an average of six to eight months for a woman to conceive through artificial insemination with frozen sperm. Many factors influence if and when a woman will conceive, including her age, the condition of her reproductive system, the method of insemination or other assisted reproductive procedure and whether fertility drugs are used.
