Effect of seminal plasma on implantation rates.

The objective of this study was to evaluate the effect of seminal plasma on implantation rates. A prospective randomized placebo-controlled clinical trial was designed, and carried out at the Center for Reproduction and Transplantation Immunology. Eighty-seven women experiencing unexplained infertility and/or recurrent spontaneous abortion were recruited into the study and were randomized into groups using vaginal capsules containing seminal plasma or placebo (lubrication jelly). Implantation rates documented by the appearance of an intrauterine gestational sac visible on transvaginal ultrasonographic examination by the 6th week of gestation were compared between women receiving either seminal plasma or placebo. The results obtained from this study demonstrated that, of the 87 women participating in the study, 23 (26%) did not achieve pregnancy within 1 year. Nine of these infertile women received seminal plasma and 14 received placebo. Implantation rates were higher among women receiving seminal plasma (35/44, 80%) compared to placebo (29/43, 67%). The conclusions drawn from this study suggest that vaginal capsules containing seminal plasma appear to enhance implantation. They, therefore, may be useful in the treatment of couples undergoing assisted reproductive technologies or with unexplained infertility.