TRANSFER OF CRYOPRESERVED EMBRYOS IMPROVED PREGNANCY RATES IN PATIENTS WITH DAMAGE TO THE FUNCTIONAL INTEGRITY OF THE SPERM MEMBRANE AS MEASURED BY THE HYPOOSMOTIC SWELLING TEST
Jh. Check et al., TRANSFER OF CRYOPRESERVED EMBRYOS IMPROVED PREGNANCY RATES IN PATIENTS WITH DAMAGE TO THE FUNCTIONAL INTEGRITY OF THE SPERM MEMBRANE AS MEASURED BY THE HYPOOSMOTIC SWELLING TEST, Fertility and sterility, 65(6), 1996, pp. 1241-1244
Objective: To compare the pregnancy rates (PRs) after transfer of cryo
preserved embryos in patients who have damage to the functional integr
ity of the sperm membrane as measured by the hypo-osmotic swelling tes
t to those without this defect. Design: Prospective clinical study. Se
tting: University-associated IVF center. Patients: Fifty-four patients
enrolled in a matched prospective study to evaluate the effects of lo
w HOS scores (<50%) on PRs after IVF-ET were followed to determine the
PR after transfer of cryopreserved embryos. Main Outcome Measure: Cli
nical PRs and implantation rates. Results: Fourteen patients with low
hypo-osmotic swelling test scores underwent 21 frozen ET cycles, achie
ved four clinical pregnancies for a PR per cycle of 19.0% and an impla
ntation rate of 7.1%. Twelve patients with normal hypo-osmotic swellin
g test scores underwent 21 frozen ET cycles, achieved five pregnancies
for a clinical PR per cycle of 23.8% and an implantation rate of 9.3%
. Conclusion: Previous studies have demonstrated an adverse effect of
low hypo-osmotic swelling test scores on PRs after IVF-ET despite norm
al fertilization. This adverse effect was not found in the transfer of
cryopreserved embryos from males with low hypo-osmotic swelling test
scores. Further investigation is required to determine how cryopreserv
ation improves the chances of implantation of these embryos.