Rd. Oates et al., EFFICACY OF INTRACYTOPLASMIC SPERM INJECTION USING INTENTIONALLY CRYOPRESERVED EPIDIDYMAL SPERMATOZOA, Human reproduction, 11(1), 1996, pp. 133-138
Microsurgical epididymal sperm aspiration was a great advance In the t
herapy of patients with non-reconstructable, obstructive azoospermia,
most notably congenital bilateral absence of the vas deferens. Using c
onventional in-vitro fertilization, pregnancies were rarely achieved b
ecause the rate of oocyte fertilization was extremely poor, However, t
he use of retrieved spermatozoa in conjunction with intracytoplasmic s
perm injection (ICSI) has dramatically increased the likelihood of emb
ryo formation, Typically, sperm and oocyte harvesting are performed si
multaneously, We have investigated whether frozen-thawed spermatozoa w
ork as well as fresh spermatozoa, When we had concluded from our own p
opulation of patients (groups I and II) that they did, we adopted a po
licy of aspirating spermatozoa, primarily cryopreserving them and usin
g them for ICSI at a later date, We found the fertilization rates of t
his latter cohort of patients (group III) to be excellent (37% per ooc
yte), and the ongoing pregnancy rate is quite satisfactory (40% per co
uple, 29% per cycle), We offer this approach as an alternative to the
traditional scheme because it markedly eases the burden of partner sch
eduling on both the couple and the clinicians involved. In addition, a
ssurance of the availability of male partner spermatozoa can be attain
ed prior to beginning ovulation induction.