A considerable variation in pregnancy rates has been observed among patients undergoing intrauterine insemination (IUI) along with controlled ovarian stimulation. Also, several researchers have reported difficulties in evaluating IUI results due to the patient heterogeneity and the diverse stimulation protocols adopted. Now, a recent retrospective study published in the journal Fertility and Sterility defines the characteristics of couples that would determine the higher chances of pregnancy through IUI.
Philippe Merviel, from the Department of Gynecology, Obstetrics and Reproductive Medicine, Amiens University Medical Center, France, and colleagues, evaluated 1,038 IUI cycles conducted in 353 couples, to determine the factors leading to successful pregnancy. Ovarian stimulation was performed by administering daily subcutaneous injection of follicle stimulating hormone (FSH) or human menopausal gonadotropin (hMG). Following the stimulation of ovulation, IUI was performed after 36 hours after obtaining at least one follicle of >16 mm in size, with endometrial thickness of >7 mm. The clinical pregnancy rates were calculated based on the following factors:
• Woman’s age
• Type of infertility
• Characteristics of spermogram
• Total motile spermatozoa (TMS) count
• Estradiol (E2) level before hCG injection
• Number of mature follicles
Based on the study results, the characteristics of the couples that would influence optimal treatment outcomes were described as follows:
• Women below 30 years of age with cervical or anovulatory infertility
• Men with TMS of ≥5 million
Additionally, the researchers reported that an ideal stimulation cycle may aid in the recruitment of two follicles measuring >16 mm on the day of hCG administration, with estradiol level >500 pg/mL. The study findings also showed that the best treatment results can be achieved with the use of a soft catheter for performing IUI.
IUI along with controlled ovarian stimulation is the preferred first-line treatment for patients with patent fallopian tubes and diverse causes of infertility. However, the overall treatment success rate is still debated, and is reported to be influenced by several factors. Earlier, Rawal et al (Journal of Obstetrics and Gynecology, 2008) conducted a postal survey to investigate practitioners’ opinions regarding such factors. During the survey, the practitioners, including consultants, infertility nurse specialists, and other clinicians, were requested to fill up a questionnaire comprising of 22 parameters, and to rate each factor on a 1 to 10 scale. The factor that obtained the highest rating during the study was follicular number on the day of hCG administration. This was succeeded by follicular size, total sperm count, and the requirement of a standardized protocol for all the unit staff.
The wide variations noticed in the IUI treatment approach has been attributed as the probable factor contributing to substantial inconsistencies in pregnancy rates. Hence, future prospective studies should be directed towards arriving at a consensus on the critical factors influencing the success of IUI and the standardization of treatment protocol.
References
1. Merviel P, Heraud MH, Grenier N, Lourdel E, Sanguinet P, Copin H. Predictive factors for pregnancy after intrauterine insemination (IUI): An analysis of 1038 cycles and a review of the literature. Fertil Steril. 2010 Jan;93(1):79-88.
2. Rawal N, Drakeley A, Haddad N. Intrauterine insemination practice in the UK. J Obstet Gynaecol. 2008 Oct;28(7):738-41.
