In some cases , sperm are formed in the testis but are not present in the ejaculate due to a blockage or absence of vas deferens , patients with ejaculatory dysfunction or presenting with necrozoospermia ( all dead sperm in ejaculation ). Viable sperm can be usually recovered by testicular biopsy ( TESE ) or by aspirating from the proximal part of the epididymis ( PESA ) and can be used to fertilize the egg by ICSI procedure. We are the pioneer in the micro-manipulative techniques. Our success with these techniques led to the establishment of the first TESE / ICSI pregnancy and delivery in Thailand since 1996.