POSTWASH TOTAL MOTILE SPERM COUNT EFFECT ON PREGNANCY OUTCOMES IN INTRAUTERINE INSEMINATION

Abstract

Intrauterine insemination (IUI) is a frequently used method to treat couples with infertility. There is evidence of decreased pregnancy rates with total motile sperm count (TMSC) less than 5 and 10 million (1,2), yet there has been efficacy of reported IUI success with TMSC under 1 million (2). As such, there remains to be a consensus on semen parameters for which to recommend IUI in the infertile population. Further defining TMSC and associated pregnancy rates allows for more precise patient counseling and may also delineate a clearer threshold for escalation of care to in vitro fertilization. This may decrease the time to pregnancy and the financial burden of offering infertility treatment that is less likely to be effective. The aim of this study was to determine a minimum threshold of TMSC on semen analysis to offer IUI cycles. A retrospective cohort study of all IUI cycles at a private practice infertility center from June 2014 to May 2018. This is a retrospective cohort study of all IUI cycles at a private practice infertility center from June 2014 to May 2018. We obtained female characteristics including age, gravida, parity, BMI, AMH, AFC, tubal patency, stimulation, number of dominant follicles, and ET. Semen was processed with a gradient centrifugation process and the following semen parameters were collected: post wash TMSC, concentration, motility, and wet mount morphology. Our primary outcome of interest was the presence or absence of clinical pregnancy after each cycle. Clinical pregnancy was defined as fetal cardiac activity on ultrasound. A total of 999 women underwent 2169 IUI cycles during this four-year period. The average couple underwent 2.17 IUIs. The overall clinical pregnancy rate was 19.8% per cycle while pregnancy rate of only the first IUI per patient was 19.2%. Overall, clinical pregnancy rate per couple was 40.2%. During the first IUI each couple underwent, there was an increase in clinical pregnancy with increasing TMSC, OR 0.44 for TMSC ≤1M, 0.56 for TMSC 2-5M, and 0.99 for TMSC 6-10M, compared to TMSC >10M with p-values of 0.27, 0.057 and 0.975 respectively. Using receiver operating characteristic curves, we did not identify a TMSC threshold to offer IUI but rather a linear increase of sensitivity and specificity to predict pregnancy with increased TMSC. The lowest TMSC resulting in pregnancy was 660,000. With TMSC 6-10M, pregnancy outcomes improved with morphology >4% OR 0.84, compared to morphology <4% OR 0.25. There were 39 multifetal gestations, 9.1% of all clinical pregnancies. Although no distinct threshold of TMSC was identified to offer IUI versus proceeding with ART, there is a positive correlation between TMSC and IUI success. There appears to be improved outcomes with morphology >4% when TMSC <10. A follow up study, using a larger sample size, is necessary to further characterize the upper limits of efficacy of IUI specimens. Well-defined pregnancy rates based on semen parameters will allow for more direct counseling of infertility patients and also allow for more targeted therapy recommendations based on pregnancy success rates.