Objective: To examine pregnancy outcome with two methods of semen preparation for intrauterine insemination (IUI).
Design: Prospective and randomized study.
Settings: Academic tertiary center.
Patient(s): Three hundred eleven couples undergoing 676 consecutive cycles of assisted conception using IUI.
Intervention(s): Semen samples collected for IUI were randomized to wash only or density gradient centrifugation (DGC) processing.
Main outcome measure(s): Various prepreparation and postpreparation semen parameters were used for IUI. The influence of the method of semen processing, and impact of various semen parameters and female factors on pregnancy were examined by receiver operating characteristics (ROC) curves, logistic regression, and life table analysis.
Result(s): Of the 676 cycles, 88 resulted in conception leading to an overall clinical pregnancy rate of 13.0% per cycle and 28.3% per patient with a miscarriage rate of 34.0%. Eighty-eight percent of pregnancies occurred in the first three cycles of IUI and 95.5% within the first four cycles. The pregnancy rate for wash only was 11.6% (37 of 319) and the rate for DGC was 14.3% (51 of 356). However, in samples with <22 million motile sperm in the inseminate, pregnancy rates were 4% for wash and 18% for DGC. The woman's age for both methods and the percentage of sperm in the original semen with a velocity of > or =80 micro m/s for the wash method influenced pregnancy outcome.
Conclusion(s): Although samples with an acceptable number of motile sperm can be processed efficiently by wash only, poor quality semen samples should be processed using DGC.