Comparison of the sperm quality necessary for successful intrauterine insemination with World Health Organization threshold values for normal sperm.

OBJECTIVE

To compare World Health Organization threshold values for normal sperm with the initial sperm quality necessary for successful IUI.

DESIGN

Retrospective study.

SETTING

Private fertility clinic.

PATIENT(S): One thousand eight hundred forty-one couples undergoing 4,056 cycles of IUI.

INTERVENTION(S): Intrauterine insemination.

MAIN OUTCOME MEASURE(S): Relation of initial sperm quality to fecundity.

RESULT(S): Progressive motility and total motile sperm count were the initial sperm characteristics most closely related to pregnancy on discriminant analysis. The per-cycle pregnancy rate averaged 11.1% during the first three IUI cycles. Pregnancy rates were > or = 8.2% per cycle when the initial sperm values were a concentration of > or = 5 X 10(6)/mL, a total count of > or = 10 X 10(6), progressive motility of > or = 30%, or a total motile sperm count of > or = 5 x 10(6). Minimal increases in fecundity occurred when initial values were greater than these threshold levels. The lowest initial values that resulted in pregnancy were a concentration of 2 x 10(6)/mL, a total count of 5 x 10(6). motility of 17%, and a total motile sperm count of 1.6 X 10(6). Pregnancy rates were <3.6% when initial values were between the threshold levels and the lowest levels.

CONCLUSION(S): The sperm quality that is necessary for successful IUI is lower than World Health Organization threshold values for normal sperm. Intrauterine insemination is effective therapy for male factor infertility when initial sperm motility is > or = 30% and the total motile sperm count is > or = 5 X 10(6). When initial values are lower, IUI has little chance of success.