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Semen Analysis
Semen specimens are obtained by masturbation into a sterile wide-mouth container after 3 days of abstinence and analyzed within 2 hr of collection. Two to three analyses, separated by at least a month, are required for a meaningful evaluation.
In the setting of a recent febrile illness or exposure to gonadotoxic agents we would repeat the semen analysis no sooner than 3 months later. Semen is initially an opalescent coagulum that liquefies within 20-25 min of ejaculation. The coagulation protein derives from the seminal vesicle. Liquefaction is secondary to the action of prostatic proteases. Failure of liquefaction is due to abnormalities of the prostate or its ducts. Normal ejaculate volume is between 2 and 6 mL.
i. Seminal vesical------ 65%
ii. Prostate----------- 30-35%
iii. Vasa ----------------- 3-5%
Seminal fructose derives from the seminal vesicles. Azoospermia coupled with low ejaculate volume of nonclotting watery fluids fructose-negative, Usually implies an obstruction of the ejaculatory duct. If the vasa are Palpable a transrectal Ultrasound can be diagnostic. Patients who are not azoospermic but oligo- or asthenospermic with a low semen volume may have partial ejaculatory duct obstruction or retrograde specimen is obtained by first having ejaculation. A postejaculatory urine specimen is obtained by first having the patient empty his bladder prior to ejaculation and then voiding following ejaculation into a separate container. Retrograde ejaculation is commonly seen in diabetics as well as in men who have had transurethral surgery at or near the bladder neck
Manual light microscopic evaluation of sperm concentration, motility, and morphology is still the gold standard. Computer-assisted semen analysis (CASA) is most useful as a research tool and yet has not provided information that alters therapy. Azoospermic specimens are frequently misread by the computer as oligospermic and computerized morphology has not been perfected. CASA provides interesting information on sperm velocity and angularity that is useful in a research setting. Because pregnancy can be achieved with only one sperm, Specimens originally read as azoospermic should be centrifuged and the pellet examined for sperm. Specimens with head-to-head or tail-to-tail agglutination are evaluated for antisperm antibodies or infection. Infection may be inferred from the presence of leukospermia (>1x 106 WBC/mL). Men with agglutination or leukospermia should have their semen cultured for aerobic and anaerobic organisms as well as Chlamydia and Mycoplasma.
The penis and scroturn should be washed with an antibacterial scrub Prior to culture to avoid inadvertent contamination with skin or fecal flora.Proper interpretation of morphologic parameters requires an understanding of the scoring system and criteria employed by testing laboratory, broadly viewed; profound abnormalities in morphology are associated with poor fertilizing capacity when strict criteria (Kruger) are used. Men with fewer than 40% perfectly shaped sperm usually failed to fertilize without micromanipulation.
Large numbers of tapered sperm are seen in testes with elevated temperatures, such as varicocele, cryptorchid, or retractile testes, or in the testes of men who take saunas or hot baths. Antisperrn antibodies bound to sperm are associated with lower pregnancy rates. Risk factors for antibodies include torsion, epididymitis, orchitis, unilateral or partial obstruction, and large varicoceles.
These are all conditions associated with impairment of the blood-testis barrier that usually prevents sperm antigens (which appear at puberty) from being exposed to the general circulation. An immunobead assay detects antibodies on the sperm and in the serum.
# High levels of antibodies are most often seen with obstruction, in particular before (in serum) and after (in serum and on sperm) vasectomy reversal.
# Low levels of antibodies on sperm and moderate levels in serum are usually seen in men with large varicoceles.
A postcoital test is useful for evaluating sperm-cervical mucus interaction. A fair to good semen analysis associated with a poor postcoital test is an indication for intrauterine insemination (IUI). Although IUI can overcome cervical mucus antibodies or decreased counts,
The success of IUI is dependent on the sperm's ability to fertilize an egg.
Therefore prior to instituting IUI, we obtain a sperm penetration assay (SPA) that assesses the sperm's ability to bind and penetrate hamster oocytes, which have been rendered zona pellucida-free. Tests are interpreted as percent oocytes penetrated or sperm penetrations per oocyte. These tests are not perfect but do correlate about 80% with the ability to penetrate human eggs in vitro.
Semen Analysis Normal Ranges (WHO Criteria, 1992) Semen Characteristics Units WHO (1992)
Volume ml 2.0 or more
pH pH units (7.2 - 8.0)
Sperm concentration x 106/ml 20 or more
Total sperm count x 106/ejaculate > 40 or more
Motility (within 60 minutes of ejaculation) % Motile > 50 or more
Progression at 37oC Scale 0-4 3 - 4
Morphology % Normal sperm >=30
Vitality % Live sperm >=75
White blood cells x 106/ml <1.0
Endocrine Evaluation
Basic endocrine evaluation includes measurement of# Serum testosterone (T)
# Follicle-stimulating hormone (FSH)
Testosterone is necessary for the development and maintenance of secondary sexual characteristics and libido as well as initiation and maintenance of sperrnatogenesis.
Serum FSH crudely reflects the status of the serniniferous epithelium. Elevated serum FSH results from impaired secretion of inhibin, a Sertoli cell product that normal feeds back at the pituity and hypothalamus to turn off FSH secretion and suggests abnormalities in the seminiferous epithelium and subsequently spermatogenesis. An FSH level greater than two to three times the upper limits of normal suggests severely impaired seminiferous tubule , but may still be treatable.
# Luteinizing hormone (LH)
Is stimulatory to the Leydig cells and hence T production. Isolated LH abnormalities are very rare. LH levels need be obtained only in men with abnormal T levels
.Low levels of FSH, LH, and T are diagnostic of hypogonadotropic hypogonadism. These men have a delay or failure in the onset of puberty and therefore poorly developed secondary sexual characteristics and small firm testes. Testosterone replacement will masculinize these men but testicular growth and the initiation of spermatogenesis requires gonadotropin replacement. Hypogonadotropic hypogonadism is usually due to a pituitary tumor, with the most common pituitary lesion being a benign prolactinoma. These are usually associated with a decreased libido, an elevated serum prolactin level, and decreased serum T and LH levels. Both macro and microadenomas are often best treated with bromocriptine. Serum estrogens, prolactin, and adrenal steroids are only measured if clinically indicated (low serum T, decreased libido, gynecomastia, or a history of precocious puberty).
Men who are incompletely masculinized have disproportionately long extremities due to absent or deficient androgen stimulation required for epiphyseal closure at the time of puberty. This is seen in men with hypogonadotropic hypogonadism (Kallmann's syndrome when associated with absent sense of smell or other midline defects) or Kleinfelter's syndrome.
After evaluation of body habitus, the thyroid is palpated and the heart and lungs auscultated. Chronic bronchitis associated with congenital epididymal dysplasia is seen in Young's syndrome.
Situs inversus with associated immotile sperm is seen in immotile cilia (Kartagener's) syndrome.
The breasts are observed and palpated for gynecomastia, which can be associated with estrogen secreting testicular neoplasms, adrenal tumors, and liver disease. Nipple discharge or tenderness may be seen with prolactin-secreting pituitary adenomas.
The abdomen is palpated and percussed. A large varicocele that does not collapse in the supine position warrants a search for an abdominal mass. An enlarged liver suggests hepatic dysfunction, which may be associated with infertility due to altered sex steroid metabolism.
The penis and urethral meatus is examined for condylomata. The urethra is milked for discharge. The location of the meatus is noted. Severe hypospadias may result in inadequate delivery of semen into the vagina.
Scrotal examination is first performed with the patient supine. This allows a varicocele, if present, to collapse; testis size and consistency can then be properly assessed. Use an orchidometer to measure testicular size. Normal testicular volume ranges from 15 to 30 cm . The testes should be firm in consistency. A change in testicular consistency is indicative of testicular pathology. Small soft testes indicate poor spermatogenesis. Small hard testes suggest postorchitis or posttorsion atrophy or Kleinfelter's syndrome.
Focal irregularities in consistency raise the suspicion of malignancy. Smooth firm nodules palpated on the surface of the testis usually represent tunica albuginea cysts. Mobile small hard bodies,corpora amylacea, may be palpated floating within the tunica vaginalis. Transillumination of the scrotum in a darkened room differentiates solid from cystic masses. In general, testes that are normal in size and-consistency usually have normal sperm production, whereas small-volume, soft testes are associated with impaired spermatogenesis.
The normal epididymis, posterolateral to the testes, is soft and barely palpable. Induration, modularity, or irregularities are suggestive of epididymal pathology. A full, firm, easily outlined epididymis that is nontendcr suggests epididymal obstruction. Epididymal cysts or spcruiutoccies are firm, smooth, transilluminate, and almost always located in the caput.
The vas deferens should be palpated bilaterally. The vas is the diameter and consistency of a venetian blind cord, and is usually posteromedial and separate from the internal spermatic cord structures. We have observed bilateral congenital absence of the vas deferens (CAV) in 1.3% of of patients presenting for infertility evaluation. With a relaxed scrotum, the diagnosis of CAV can almost always be made by palpation. These men will have azoospermia associated with low seminal volumes and nonclotting clear ejaculate. Serum follicle-stimulating hormone (FSH) is usually normal, reflecting normal spermatogenesis. Testes biopsy and scrotal exploration are not necessary prior to therapy. Because the vas deferens derives from the ureteral bud, CAV is associated with. an 11% incidence of renal agenesis and abnormalities. A renal sonogram should be obtained in all men with CAV. Most men with CAV test positive for cystic fibrosis gene mutations, although they do not have any pulmonary manifestations of this disease.We test the patient and their wives for cystic fibrosis (CFTR) gene mutations and refer the couples for genetic counseling.
Men with cystic fibrosis (CFTR mutations in association with digestive and/or pulmonary problems) will often have bilateral congenital absence of the vas deferens. CAV, whether associated with cystic fibrosis or not, may be treated using sperm retrieval and in vitro fertilization to effect pregnancies.
Large varicoceles are readily seen through the relaxed scrotal skin in a warm room with the patient standing. Small varicoceles may be appreciated as a distinct impulse and palpable dilation of the internal spermatic veins during the Valsalva maneuver. The best method to elicit a strong and sustained Valsalva is to tell the patient to bear down as if having a bowel movement. If a varicocele is detected, the patient should be placed supine. A varicocele should completely collapse when the patient is supine. A large varicocele, which does not collapse in the supine position, leads to suspicion of a retroperitoneal mass and an abdominal sonogram is indicated. In the hands of an experienced sonographer scrotal ultrasound with color flow Doppler is useful in the evaluation of questionable varicoceles, especially in obese men or men with a small tight scrotum. Our monographic criteria for the diagnosis of a varicocele is the presence of any internal spermatic veins greater than 3 mm in diameter associated with retrograde flow on Valsalva. Subclinical or questionable varicoceles are of limited clinical interest. Our data has clearly shown that response to varicoceletomy is related to varicocele size. Men with large varicoceles sustain a greater improvement in semen quality following varicocele surgery than men with small or subclinical varicoceles. Digital rectal examination is always performed. The size and consistency of the prostate is noted. Masses, cysts, irregularities, tenderness, and whether or not the seminal vesicles are palpable are noted. Stool should be tested for occult blood
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