The transcriptome of spermatozoa used in homologous intrauterine insemination varies considerably between samples that achieve pregnancy and those that do not.

OBJECTIVE

To differentiate transcripts' expression in the sperm from patients who achieved pregnancy in their first IUI cycle from those who did not. Basic sperm analysis is limited to forecasting pregnancies by means of assisted reproduction. New assays, such as microarray analysis, are potential predictive tools for this purpose.

DESIGN

Nested case-control study.

SETTING

University-affiliated private setting.

PATIENT(S): Twenty sperm samples were obtained from infertile males undergoing their first IUI cycle with healthy partners. Sperm samples with which pregnancy was achieved (P; n=10) and those with which it was not achieved (NP; n=10) were identified and their respective messenger RNA expression profiles were compared.

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): Using microarrays, global genome expression was compared in pooled samples from each group. Results were evaluated to detect differentially expressed transcripts (TDEs; FC>2; P<0.05) and to identify those transcripts that were expressed in only one of the groups (exclusive transcripts [ETs]).

RESULT(S): In group P, 756 TDEs presented increased expression, whereas 194 in group NP were found to be overexpressed. Furthermore, we found 741 ETs that were expressed only in group P and 976 that were expressed only in group NP.

CONCLUSION(S): Results reveal profound differences between expression profiles of sperm samples that impregnate successfully and those that do not. These differences might improve the predictive power of sperm evaluation to estimate IUI success by complementing the basic sperm analysis.