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Artificial Insemination Artificial Insemination, originally, the process in which male gametes, the spermatozoa, are collected and introduced artificially into the female genital tract for the purpose of fertilization (see Reproduction: Sexual Reproduction: Insemination). Other artificial methods for achieving fertilization have since been devised. Artificial insemination was first developed for breeding cattle and horses. Spermatozoa are collected from a chosen male and frozen, then thawed and used to impregnate females. Frozen human spermatozoa are now also used for insemination‹most often from an anonymous male donor when a couple wishes to have a child but the husband is infertile. Use of frozen spermatozoa leads to pregnancy about 60 percent of the time, whereas freshly collected semen has a much higher success rate of about 90 percent. Neither method is known to result in an increase in birth defects, but frozen semen often becomes unusable after a long time. A different method of artificial insemination is the mixing of sperm and ovum in a nutrient medium outside the woman's body, followed by implanting the fertilized egg into her uterus. This technique is used when a woman's fallopian tubes (see Fallopian Tube) are blocked, and, as a result, the spermatozoa cannot reach the ovum. The first baby born as a result of such a procedure was the English "test-tube baby," Mary Louise Brown, in 1978. In 1984 a further advance in this procedure was reported from Australia, with the embryo first being frozen for two months before it was successfully implanted. Yet another method was used that same year, in which the ovum was first fertilized within one woman's uterus and then transferred to the body of another woman. Eggs can now also be removed from a woman's ovaries and placed in her fallopian tubes along with her husband's sperm; normal fertilization then follows. Controversies have arisen over the legal and ethical status of some of these procedures, which have been widely used. Definition taken from, Microsoft® Encarta® Online Encyclopedia 2001 http://encarta.msn.com © 1997-2001 Microsoft Corporation. All rights reserved.
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