Infertility and Assisted Reproductive Technologies

Published on 10/03/2015 by admin

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Last modified 10/03/2015

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Chapter 34 Infertility and Assisted Reproductive Technologies

It is estimated that 10% to 15% of couples in the United States are involuntarily infertile. Newer reproductive technologies such as in vitro fertilization (IVF) and embryo transfer are increasing the success of treatment for this condition.

A couple is considered infertile after unsuccessfully attempting to achieve pregnancy for 1 year. Infertility is termed primary when it occurs without any prior pregnancy and secondary when it follows a previous conception. Some conditions, such as azoospermia, endometriosis, and tubal occlusion, are more common in women with primary infertility, but virtually all conditions occur in both settings, making the distinction of little clinical significance.

image Basic Evaluations

Evaluation and therapy may be started earlier when obvious defects are identified, or they may be delayed, for instance, when a correctable factor, such as infrequent intercourse, is identified.

In general, the first 6 to 8 months of evaluation involve relatively simple and noninvasive tests and the performance of a radiologic evaluation of tubal patency (hysterosalpingography, or HSG), which can sometimes have a therapeutic effect. In some studies, use of an oil-based dye about doubled the success rate after HSG. Operative evaluation by laparoscopy is thus reserved for the small proportion of couples who have not conceived after 18 to 24 months or who have specific abnormalities or indications of a probable pelvic factor.

To keep the status of the evaluation in mind, it is helpful to arrange the workup under a series of five categories that can be mentally reviewed at each visit. Table 34-1 shows the approximate incidence and the tests involved in the evaluation of each category. Box 34-1 summarizes the treatment options for infertility. In 5% to 10% of couples, no explanation can be found (idiopathic infertility).

TABLE 34-1 COMMON INFERTILITY FACTORS

Factor Incidence (%) Basic Investigations
Male, coital 40 Semen analysis
    Postcoital test
Ovulatory 15-20 Urinary luteinizing hormone self-test; serum progesterone
Cervical 5 Postcoital test
Uterine, tubal 30 Hysterosalpingogram
    Laparoscopy
Peritoneal 40 Laparoscopy

Investigations only when menses are regular (every 22 to 35 days); oligomenorrhea generally requires treatment.

image Etiologic Factors

MALE COITAL FACTOR

Investigations

A semen analysis should be performed following a 2- to 4-day period of abstinence. The entire ejaculate should be collected in a clean, nontoxic container. Until relatively recently, the full range of normal variation was not appreciated. Characteristics of a normal semen analysis are shown in Table 34-2.

TABLE 34-2 CHARACTERISTICS OF NORMAL SEMEN ANALYSIS

Characteristics Quantity
Semen volume 2-5 mL
Sperm count Greater than 20 million/mL
Sperm motility Greater than 50%
Normal forms Greater than 30% standard morphology or greater than 14% “strict” morphology
White blood cells Fewer than 10 per high-power field or 1 × 106/mL

At least 25% A motility or 40% A plus B motility.

An excessive number of leukocytes (more than 10 per high-power field) may indicate infection, but special stains are required to differentiate polymorphonuclear leukocytes from immature germ cells. Semen quality varies greatly with repeated samples. An accurate appraisal of abnormal semen requires at least three analyses. Periodic reassessment is necessary.

Endocrine evaluation of the male with subnormal semen quality may uncover a specific cause. Hypothyroidism can cause infertility, but there is no place for the empirical use of thyroxine. Low levels of gonadotropins and testosterone may indicate hypothalamic-pituitary failure. An elevated prolactin concentration may indicate the presence of a prolactin-producing pituitary tumor. An elevated level of follicle-stimulating hormone (FSH) generally indicates substantial parenchymal damage to the testes,