Does the absence or presence of seminal fluid matter in patients undergoing ovulation induction with intrauterine insemination?

Sperm preparations for intrauterine insemination (IUI) generally do not include seminal fluid, and it is not known whether the absence of this component affects pregnancy rates. Therefore we evaluated the effect of high intravaginal seminal fluid deposition on clinical pregnancy rates in patients undergoing ovulation induction and IUI therapy. A prospective, randomized, double-blind study was designed for an infertile population in a university-based infertility practice. Patients were randomized to receive high vaginal deposition of either seminal fluid separated from the husband's ejaculate (study group) or normal saline solution (control group). Intercourse was restricted. A comparison of clinical pregnancy rates per cycle between study and control groups showed no significant difference between them [22/164 (13.4%) and 19/155 (12.3%) respectively]. Furthermore, in non-participants with unregulated intercourse, the pregnancy rate per cycle was not significantly different (40/307; 13.0%). Miscarriage rates between the study and control groups were similar. As high intravaginal deposition of seminal fluid at the time of IUI does not improve the clinical pregnancy rate in patients undergoing ovulation induction and IUI therapy, our study suggests that, after ejaculation, clinically significant biological contributions of seminal fluid to the achievement of pregnancy are bypassed by well-timed IUI.