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Fatherhood without sperm in the ejaculate December 2001 Initial Presentation Annabelle and Barry have been trying to conceive for 15 months during which time they have had unprotected intercourse 3 to 4 times a week. Annabelle's periods have been regular with minimal dysmenorrhoea. She has had no significant past medical history and has never been pregnant. Her recent Pap smear and vaginal examination were normal.
Follow up Consultation More detailed history was elicited from Barry in relation to possible causes of his azoospermia. There was no history of delayed testicular descent, delayed puberty, adult onset orchitis, exposure to irradiation, chemotherapy, pesticides or recurrent chest infections. Genital examination revealed no abnormality of the penis, normal sized testes (20 mls in volume) which were of normal consistency and no varicocoele. Rectal examination was normal. Consultant Comment The association of azoospermia with normal sized testis, normal serum FSH and low semen volume is suggestive of obstruction to the passage of sperm, although a defect in spermatogenesis is still possible. Obstruction to sperm flow may occur in the epididymis (essentially a single, tortuous tube approximately 60 cm long) or in the vas deferens. Causes of obstructive azoospermia are shown in Table 1. Although some obstructions are correctable by surgery, restoration of fertility is less likely and better results are obtained with assisted reproduction. This is not only because obstruction tends to be at many sites and is difficult to bypass but also because obstruction leads to secondary sperm auto-antibody production which can affect motility of sperm adversely. Further Progress Annabelle and Barry are referred for advice about assisted reproduction or adoption. A repeat semen analysis report is as follows:
Further investigations included tests for mutation in the CFTR gene (for cystic fibrosis) karyotype and Y deletion. These were reported as follows:
A diagnosis of congenital absence of the vas deferens was made. Karyotype - normal male and no deletions of Y chromosomes were detected. Following discussion of the various options available Barry underwent aspiration of the testes and epididymis which resulted in collection of good numbers of viable sperm. Some were used for injection into oocytes collected from Annabelle and the rest of the sperm were able to be cryopreserved for future use. Consultant Comment The strong clinical impression of obstructive azoospermia due to congenital absence of the vas was supported by the semen analysis which showed a low volume, reduced pH and a low total seminal fluid fructose. Congenital absence of the vas is often associated with absence of the seminal vesicles which provide fluid, bicarbonate and fructose to the semen. In 85% of patients with congenital bilateral absence of the vas, there is a mutation in the Cystic Fibrosis Transmission Regulator (CFTR) gene. These mutations result in a reduced amount of the CFTR protein which is required for normal passage of chloride in the apical membranes of epithelial cells. Deficiency of this protein may cause a variety of abnormalities, including obstruction of the Wolffian duct with subsequent atrophy of the vas deferens, part of the epididymis and the seminal vesicles. More complete absence of the protein may result in progressive lung disease, pancreatic exocrine insufficiency and elevated sweat electrolytes, characteristic of cystic fibrosis. Clinical cystic fibrosis results from inheritance of two recessive alleles containing a mutation in the gene. Since congenital absence of the vas implies at least one recessive gene is carried by Barry, it is important to check that Annabelle does not also, by chance, carry a mutation. Genetic testing of both partners reduces, but does not entirely exclude, the occurrence of cystic fibrosis in a child. This is because routine genetic testing does not detect all the possible mutations leading to an abnormal CFTR protein but also because some mutations in the CFTR gene lead to a reduced amount of an otherwise normal protein. Although Barry has no duct to transport sperm from the testes, normal spermatogenesis still occurs and it is possible to obtain motile, mature sperm by aspirating the testis. This is done as a day procedure at the same time as oocytes are collected from Annabelle. Barry's sperm is then injected into Annabelle's oocytes with a high expectation of successful fertilisation and pregnancy. Causes of Azoospermia Absent Spermatogenesis Chromosomal (Klinefelters, Y deletions Genetic (myotomic dystrophy) Trauma (torsion, cryptorchidism) Drugs (cytotoxics, sulphasalazine) Pituitary (tumour, Kallmann's) Failed Ejaculation Organic (cord injury, diabetes) Functional (anxiety, medical illness) Obstruction of Sperm Transport Congenital absence of the vas Young's syndrome Infection Surgery References Chillon M, Casals T, Mercier B et al (1995). Mutations in the cystic fibrosis gene in patients with congenital absence of the vas deferens. New Eng Journ Med. 332. 1475-1480  PRINT THIS PAGE
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