23 Jul Overview on Double versus Single IUI from US Fertility Network
Intrauterine insemination (IUI) is a procedure chosen for couples with unexplained infertility, male infertility, sexual dysfunction, ovulatory dysfunction, and/or endometriosis. This technique has helped thousands of couples conceive a child who previously did not enjoy success with other methods.
Intrauterine insemination is a form of artificial insemination. With this procedure, the sperm are washed and concentrated. Then, the sperm are placed directly into the woman’s uterus at the time the ovaries release one or more eggs. The outcome of IUI is for the sperm to make it to the fallopian tubes to fertilize the egg. Depending on the cause of the infertility, IUI is coordinated with the woman’s normal reproductive cycle. Fertility medications are often used for ovarian stimulation. With double IUI, the procedure of insemination is done twice in a menstrual cycle instead of only once. The purpose of double IUI is to increase pregnancy rates.
In reproductive medicine, experts have debated whether consecutive intrauterine inseminations (double insemination) are more effective than single intrauterine insemination. Based on current scientific literature, there is little difference in the live birth rates when comparing single to double insemination. Most fertility clinics recommend single IUI.
In a recent study presented by the American Society for Reproductive Medicine (ASRM) suggests that a possible advantage to using double IUI exists for couples with male factor infertility. Considering all infertility couples in the study, the overall pregnancy rate was 11% for the single IUI group. For the double IUI group, the pregnancy rate was 12.8%, which is slightly higher. The researchers only looked at the sub-group of patients with male infertility, they found that the single IUI pregnancy rate was 9.8% compared to 17.5% for the double IUI group.
The researchers of ASRM also analyzed the outcomes according to the type of stimulation used for each couple. They found that within the male factor group, there is was great benefit for double insemination. When the women took injectable ovarian stimulation medicines (called gonadotropins), the double IUI group had a pregnancy rate of 27.5% versus only 10.8% for the single IUI group.
The reason for using double insemination is to create the opportunity for a longer fertilization periods. The eggs are inside of follicles, which are tiny sacs on the ovaries. Follicle rupture is likely after administration of human chorionic gonadotropin (hCG) for ovarian hyperstimulation (OH) with IUI cycles.
In a randomized clinical study, the researchers evaluated the effectiveness of single and double IUI in only OH cycles with multi-follicular development. They found that the single IUI group had an 11% pregnancy rate compared to 18.4% for the double IUI group for couples with unexplained infertility. For couples with male factor infertility, the rates were 10.4% and 7.7% for single and double IUI groups respectively.
Bagis T, Haydardedeoglu B, Kilicdag EB, et al. (2010). Single versus double intrauterine insemination in multi-follicular ovarian hyperstimulation cycles: a randomized trial. Human Reproduction, 25(7), 1684-1690.
Tongue et al. (2014). Comparison of the effectiveness of single versus double intrauterine insemination with three different timing regimens. Fertility, 94:1267-70.