Does increasing frequency of intrauterine insemination improve pregnancy rates significantly during superovulation cycles?

Abstract

To compare pregnancy rates (PR) per treatment cycle of controlled ovarian hyperstimulation (COH) patients receiving a single IUI with COH patients receiving two IUIs. A prospective randomized trial of consecutively treated patients attending our infertility clinic for COH and IUI. Patients undergoing COH by hMG and hCG were randomized to receive either one (group A) or two (group B) IUIs. Randomization was performed using a random number table. Group A IUIs were timed 35 hours after ovulatory hCG, whereas group B IUIs were performed 19 and 43 hours after hCG. A total of 120 patients during 169 cycles were randomized between group A (90 cycles) and group B (79 cycles). Data analysis demonstrated no significant differences between groups A and B with respect to age, indications for COH, duration of hMG treatment, total amount of hMG administered, peak E2 levels, number of dominant follicles recruited, or mean number of total motile sperm inseminated. Pregnancy rates for groups A and B were 0.11 and 0.14, respectively. The size of our study population permits a conclusion that a 300%, 200%, or 100% difference in PR between the two groups does not exist (power 0.97, 0.80, or 0.61, respectively). Among patients undergoing COH and IUI, increasing the frequency of insemination does not provide a significant increase in cycle pregnancy rate.