Artificial Insemination

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Chapter 36 Artificial Insemination

INTRODUCTION

Artificial insemination is an assisted conception method that can be used to alleviate infertility in selected couples. The rationale behind the use of artificial insemination is to increase the gamete density near the site of fertilization.1 The effectiveness of artificial insemination has been clearly established in specific subsets of infertile patients such as those with idiopathic infertility, infertility related to a cervical factor, or a mild male factor infertility (Table 36-1).2,3 An accepted advantage of artificial insemination is that it is generally less expensive and invasive than other assisted reproductive technology (ART) procedures.4

Table 36-1 Infertility Disorders with Proven Benefit from Partner Insemination

Idiopathic infertility
Cervical factor infertility
Mild male factor infertility

From Cohlen BJ: Should we continue performing intrauterine inseminations in the year 2004? Gynecol Obstet Invest 59:3–13, 2004.

This chapter provides a comprehensive description of indications for artificial insemination, issues to consider before donor insemination, complications associated with intrauterine insemination (IUI), factors affecting the success of artificial insemination, and the current evidence available on effectiveness of artificial insemination for different indications.

GENERAL CONSIDERATIONS

Intrauterine Versus Intracervical Insemination

A major breakthrough came in the 1960s when methods were developed for extracting enriched samples of motile sperm from semen. These purified samples were free of proteins and prostaglandins, and thus could be placed within the uterus using a technique designated intrauterine insemination (IUI). This technique was found to result in pregnancy rates 2 to 3 times those of intracervical insemination. However, intracervical insemination is still utilized in some practices.5

In an effort to further improve pregnancy rates, techniques were developed to place washed sperm samples directly into the tubes via transcerival cannulation (intratubal insemination) or into the peritoneal cavity via a needle placed through the posterior cul-de-sac (intraperitoneal insemination). Another technique developed in Europe, termed fallopian tube sperm perfusion, involves pressure injection of a large volume (4mL) of washed sperm sample while the cervix is sealed to prevent reflux of the sample.6 This technique appears to have a higher pregnancy rate than IUI in couples with unexplained infertility. The remainder of these technically difficult approaches have never been shown to result in better pregnancy rates than IUI. One prospective, randomized study found that simultaneous intratubal insemination actually decreased the pregnancy rates associated with IUI.7 In modern clinical practice in the United States, IUI is the predominant technique used for artificial insemination.

EVALUATION

Male Evaluation

Antisperm Antibodies

Male antisperm antibodies are found in approximately 10% of semen samples from infertile couples. Men with antisperm antibodies attached to their sperm are classified as having immunologic infertility. These antibodies are believed to decrease fertility by inducing agglutination or immobilization of the sperm. Studies have identified multiple antisperm antibodies that correspond to a variety of sperm components.

There are multiple known risk factors for the development of male antisperm antibodies.8 Vasectomy results in the development of antisperm antibodies in the majority of men. After successful vasovasostomy, more than half of these men will have detectable sperm-bound antibodies. The pregnancy rates will depend on many factors, including the titer and quantity of gross agglutination. Obstructive azospermia from any cause (e.g., congenital absence of the vas deferens, cystic fibrosis, infant hernia repair) increases the risk of antisperm antibodies. Reproductive infections (e.g., epididymitis, prostatitis, or orchitis) are also associated with antisperm antibodies.

Antisperm antibody tests are performed as a routine part of a complete semen analysis during the initial infertility evaluation. The most commonly used test in clinical practice is probably the immunobead assay.8 This quantitative assay evaluates live sperm and indicates percent bound, antibody isotype, and binding location. For routine screening, some andrology laboratories use a commercially available mixed antiglobulin reaction assay (SpermMar).

Male subfertility is significantly increased when the antisperm antibody level is greater than 50%.9,10 Antisperm antibodies interfere with sperm–zona pellucida binding and prevent embryo cleavage and early development.

INDICATIONS

Unexplained Fertility  

Male Factor Infertility

Partner insemination appears to be of clear benefit when the couple’s infertility is the result of any condition that makes it difficult to place semen high in the vagina during coitus. Male conditions resulting in this situation are termed ejaculatory failure. The most common causes of ejaculatory failure are impotence, severe hypospadias, and retrograde ejaculation. A unique condition that has been found to be treatable with artificial insemination is impotence secondary to spinal cord injury.11

Partner insemination is also commonly used as a treatment for male factor infertility documented by repeated abnormal results on semen analysis. In couples where there is mild male factor infertility, defined as a progressive sperm motility of at least 20% to 30%, the prognosis appears to be good with partner insemination. Theoretically, increasing the number of motile sperm reaching the egg should improve fertility whenever decreased numbers and motility of normally functioning sperm is the primary problem.

Unfortunately, the pregnancy rates after partner IUI for the treatment of severe male factor infertility have been disappointing.12 This is probably because markedly abnormal parameters on routine semen analysis often reflect a sperm defect that decreases the ability to fertilize eggs. This type of defect is unlikely to be overcome by increasing the number of sperm to which the egg is exposed at the site of fertilization. In patients with severely abnormal parameters on semen analysis and those with male factor infertility not amenable to partner insemination, more effective treatment will be either donor insemination or in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI).

Donor Insemination

In the past, the only available options for couples with severe male factor infertility (e.g., severe oligospermia, or failure to conceive using partner insemination) desiring children were either donor insemination or adoption. Since the widespread availability of IVF using ICSI, many couples with severe male factor infertility have chosen to procreate their own genetic children using these techniques. However, donor insemination remains an option when IVF/ICSI has been unsuccessful. Alternatively, many candidates for IVF/ICSI initially choose donor insemination because it is less invasive and ultimately more likely to achieve pregnancy for couples with limited resources.

Some women choose donor insemination because they are not candidates for IVF/ICSI. Perhaps the most obvious situation is women without male partners who seek pregnancy. The use of donor insemination is also indicated when the male partner has no viable sperm (i.e., azoospermia) or when IVF/ICSI fails to achieve fertilization. Finally, men with a known genetic disorder often choose donor insemination to avoid transmission to their children.

IUI TIMING, COST, AND FREQUENCY

Timing

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