Sperm retrieval rates in subgroups of primary azoospermic males

Men presenting with primary infertility and azoospermia may be offered surgical sperm retrieval (SSR) as a prelude to intracytoplasmic sperm injection (ICSI). We evaluated sperm retrieval rates in subgroups of men with azoospermia, based on obstructive aetiology, testicular volume and FSH.

106 patients with primary infertility underwent clinical evaluation and SSR with percuataneous epididymal aspiration (PESA) and/or testicular sperm extraction (TeSE) by a single urologist over a five year period. Ten percent of this group (11 patients) had a clear cause of obstruction, congenital absence of the vas deferens (CBAVD), labelled group A. Ninety percent (95 patients) had no definite cause of obstruction, labelled group B.

All eleven patients in group A had adequate sperm retrieved, compared with 56% of 95 men in group B. Clinical pregnancy and live birth rates were 47% and 44% for group A respectively compared with 21% and 20% for group B. Twenty-one men had testes <4 cm and FSH>10; a significantly lower sperm retrieval rate was seen in this subgroup (29%) compared to men with normal testicular volume and FSH (77%), p=0.0001, which corresponded to a LBR of 28% and 14% respectively.

In the absence of testicular histology prior to SSR clinical parameters can be used to aid in counselling. Azoospermic males with normal sized testes and normal FSH can expect acceptable numbers of sperm to be retrieved by SSR for ICSI. Less than one third of men with raised FSH and small testes will have successful SSR.