Artificial insemination

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Artificial insemination (AI) is the process by which sperm is placed into a female's vagina (specifically, into the cervix (intercervical insemination) (ICI)) or into the female's uterus (interuterine insemination) (IUI) for the purpose of impregnating the female by using artificial means rather than by sexual intercourse.

Modern techniques for artificial insemination were first developed for the dairy cattle industry to allow many cows to be impregnated with the sperm of a bull with traits for improved milk production.

Contents

[edit] Human artificial insemination

In humans artificial insemination is used as assisted reproductive technology primarily to treat infertility but is increasingly used to enable women without a male partner (i.e. single women and lesbians) to become pregnant and to produce children by using sperm provided by a sperm donor. The woman is the genetic and gestational mother of the child, and the sperm donor is the genetic or biological father of the child.

[edit] Preparations

A sperm sample will be provided by the male partner of the woman undergoing artificial insemination, but sperm provided through sperm donation by a sperm donor may be used if, for example, the woman's partner produces too few motile sperm, if he carries a genetic disorder, or if the woman has no male partner. Sperm is usually obtained through masturbation, although a special condom may be used to collect the semen during intercourse.

The man providing the sperm is usually advised not to ejaculate for two to three days before providing the sample in order to increase the sperm count.

A woman's menstrual cycle is closely observed, by tracking basal body temperature (BBT) and changes in vaginal mucous, or using ovulation kits, ultrasounds or blood tests.

When using intra-uterine insemination (IUI), the sperm must immediately be “washed” in a laboratory and a chemical is added to the sample. The process of “washing” the sperm increases the chances of fertilization and removes any chemicals in the semen that may cause discomfort for the woman.

If sperm is provided by a sperm donor through a sperm bank, it will be frozen and quarantined for a particular period and the donor will be tested before and after production of the sample to ensure that he does not carry a transmissable disease. Sperm samples donated in this way are produced through masturbation by the sperm donor at the sperm bank. A chemical known as a cryoprotectant is added to the sperm to aid the freezing and thawing process. Further chemicals may be added which separate the most active sperm in the sample as well as extending or diluting the sample so that vials for a number of inseminations are produced.

[edit] Procedure

When an ovum is released, sperm provided by the woman's male partner or by a sperm donor is inserted into the female's vagina or uterus. Semen is occasionally inserted twice within a 'treatment cycle'. If the procedure is successful, the woman will conceive and carry to term a baby. A pregnancy resulting from artificial insemination is no different from any other pregnancy.

[edit] Variations

Artificial insemination has several variations both regarding the donor of the sperm and the techniques used.

[edit] Donor variations

Either sperm provided by the woman's husband (artificial insemination by husband, AIH) or sperm provided by a known or anonymous sperm donor (artificial insemination by donor, AID or DI) can be used.

Earlier, a popular form of artificial insemination was AIC, in which the sperm of the husband and a donor were mixed. The advantage of this stated that the husband was not the biological father of the child.[citation needed] This was important in an age where artificial insemination was considered to be immoral and tantamount to adultery, with the resulting child being considered as illegitimate and having no inheritance rights.[citation needed] The popularity of AIC has reduced to almost nil for a number of reasons, including advances in genetic testing which make it fairly easy to identify the genetic father with a blood test, the advance of medical treatments for male infertility (such as ICSI), and the declining stigma of assisted reproductive technologies in general.

[edit] Techniques

The easiest way to inseminate is by intracervical insemination (ICI), where semen is injected high into the cervix with a needle-less syringe. This process most closely replicates the way in which semen is depositied by the penis in the cervix when the male ejaculates during vaginal intercourse. However, more technical procedures may be used which increase the chances of conception. For example, 'washed semen', that is, semen from which certain chemicals have been removed, can be injected directly into a woman's uterus in a process called intrauterine insemination (IUI). If the semen is not washed it may elicit uterine cramping, expelling the semen and causing pain, because of content of prostaglandins.

IUI can furthermore be combined with intratubal insemination (ITI), into the Fallopian tube although this procedure is no longer generally regarded as having any beneficial effect compared with IUI[1] ITI however, should not be confused with gamete intrafallopian transfer, where both eggs and sperm are mixed outside the woman's body and then inserted into the Fallopian tube where fertilization takes place. See also in vitro fertilisation (IVF) techniques which may involve the use of partner or donor sperm.

[edit] Success rates

Success rates for artificial insemination may be very misleading, since many factors including the age and health of the recipient have to be included to give a meaningful answer, e.g. definition of success and calculation of the total population.[2]

Generally, it is 10 to 15% per cycle using ICI, and [3] and 15-20% per cycle for IUI.[3]

[edit] Controversy

Artificial insemination has become a significant issue in recent years, particularly in debates revolving around same sex parenting, single mother parenting and surrogate parenting. Legal issues have arisen in cases where the gestational (and possibly genetic) mother decides to keep the child. Likewise, there have been debates over the rights and obligations of sperm donors.

[edit] Artificial insemination in livestock and pets

An artificial vagina used to collect semen from horses for use in artificial insemination
An artificial vagina used to collect semen from horses for use in artificial insemination

Artificial insemination is used in animals to propagate desirable characteristics of one male to many females or overcome breeding problems, particularly in the cases of horses, cattle, pigs, pedigree dogs, and honeybees. Semen is collected, extended, then cooled or frozen. It can be used on site or shipped to the female's location. The small plastic tube holding the frozen semen is referred to as a "straw". To allow the sperm to remain viable during the time before and after it is frozen, the semen is mixed with a solution containing glycerol or other cryoprotectants. An "extender" is a solution that allows the semen from a donor to impregnate more females by making insemination possible with fewer sperm. Antibiotics, such as streptomycin, are sometimes added to the sperm to control some venereal diseases.

Artificial insemination of farm animals is very common in today's agriculture industry in the developed world, especially for breeding dairy cattle (75% of all inseminations) and swine (up to 85% of all inseminations). It provides an economical means for a livestock grower to breed their herds with males having very desirable traits.

[edit] See also

[edit] Notes

  1. ^ Comparison of intracervical, intrauterine, and intratubal techniques for donor insemination. Hurd WW, Randolph JF Jr, Ansbacher R, Menge AC, Ohl DA, Brown AN.
  2. ^ IVF.com
  3. ^ a b Utrecht CS News Subject: Infertility FAQ (part 4/4)

[edit] References

  • Hammond, John, et al., The Artificial Insemination of Cattle (Cambridge, Heffer, 1947, 61pp)

[edit] External links