Advertisement

Incubating Washed Spermatozoa at 37°C Rather Than Keeping at Room Temperature (20°C) Until Intrauterine Insemination (IUI) Time Results in Higher Pregnancy Rate

      Objective

      To evaluate the effect of post-wash temperature (37°C vs. 20°C) on IUI pregnancy within clomiphene citrate (CC) or hMG treatments, using partner’s fresh sperm (PS) or donor frozen-thawed sperm (DS).

      Design

      A retrospective analysis of pregnancy outcome of 116 IUI cycles.

      Materials and methods

      Beginning on cycle day 3, women received between 50-250 mg of CC daily for 5 consecutive days, or hMG if a baseline ultrasonography revealed no ovarian cyst. Follicular development was monitored by serial trans-vaginal ultrasonography and serum estradiol concentrations in hMG-treated women, and by periodical trans-vaginal ultrasonography in CC-treated women. The dose of hMG was adjusted according to ovarian response. When the largest follicle(s) reached a mean diameter of 19 mm, ovulation was induced with 10,000 units of hCG. Sperm wash was performed using a gradient density method. Washed spermatozoa were either incubated in a water bath (37°C) or kept at room temperature (20°C) until IUI was performed within about an hour. A single IUI was performed by the same physician 36-38 hours after hCG, using women’s respective partners’ fresh sperm (PS) or donor frozen-thawed sperm (DS). Pregnancy was confirmed by trans-vaginal ultrasonographic detection of a fetal heart beat(s). Pregnancy data per IUI cycle were analyzed by least squares analysis of variance using the General Linear Models Procedure of the SAS Institute, Inc., with post-wash temperature (37°C vs. 20°C), stimulation type (CC vs. hMG) and type of sperm (Donor vs. Partner) as treatments, and age of women as covariate. IUI cycles with partner’s fresh semen specimens with sperm concentration less than 10x106 were excluded.

      Results

      Results are shown in the table.
      Tabled 1*a,b: P<0.05 DS vs. PS, CC vs. hMG, 20°C vs. 37°C. Results are corrected for age of women and other treatments; uncorrected results are given in parentheses. **a,b: P<0.01 within columns. Results are corrected for age of women, and for either stimulation type or sperm type; uncorrected results are given in parentheses.
      Table thumbnail gr1

      Conclusion

      Incubating washed spermatozoa at 37°C rather than keeping at room temperature (20°C) increases pregnancy rate, regardless of sperm type or stimulation type. Incubating washed spermatozoa at 37°C increases pregnancy rate in women inseminated with donor sperm but not with their partners’ sperm. Incubating washed spermatozoa at 37°C increases pregnancy rate in hMG-treated women but not in CC-treated women. Washed spermatozoa should be incubated at 37°C to maximize IUI pregnancy outcome.