Relationship Between Semen Regurgitation and Pregnancy Rates with Intrauterine Insemination

Abstract

BACKGROUND: Intrauterine insemination (IUI) involves the placement of a small plastic catheter into the uterus via the cervix to inject approximately 0.5ml of concentrated motile sperm. During injection or upon removal of the catheter, we occasionally identify some sample backflow from the cervix, known as regurgitation. We hypothesized the pregnancy rate would be reduced when regurgitation was present.OBJECTIVE(S): The objective of this study was to determine if the presence of regurgitation during IUI affected pregnancy rates.MATERIALS AND METHOD(S): This study was a retrospective chart review of IUIs performed between January 2009 and July 2010. Exclusion criteria included a) two IUIs in the same treatment cycle, b) use of frozen sperm for IUI, c) lack of IUI procedure documentation, or d) partner-reported sample spill. Charts were reviewed for multiple factors known to influence pregnancy rates. Regurgitation was recorded in the procedure note by the physician. The primary outcome measure was a positive pregnancy test. We calculated risk ratios (RR) and 95% confidence intervals (95% CI) using a generalized estimating equation method to estimate Poisson regression models with robust standard errors to account for within-cluster correlation.RESULT(S): From a total of 614 IUI cycles, 25 were excluded, with the remaining 589 cycles available for analysis. These cycles were performed on 257 women (1-7 cycles per patient), an average age of 32. Regurgitation was noted in 265 of 589 procedures (45%). Overall, there was no significant difference in pregnancy rates given presence or absence of regurgitation (16.6% versus 14.8%, respectively; RR 1.16, 95% CI 0.82-1.63). Results were unchanged when adjusted for confounding factors such as age, BMI, days of abstinence, total motile count, progression, agglutination, method of sperm preparation, and IUI difficulty (adjusted RR 1.04, 95% CI 0.71-1.54). However, when stratified by sperm preparation method (density gradient versus “wash only”), the presence of regurgitation decreased the likelihood of pregnancy in the “wash only” group (n= 152 IUIs) when compared to those without regurgitation (1.4% versus 11.0%, respectively; adjusted RR 0.11, 95% CI 0.01-1.07). Regurgitation was not associated with pregnancy outcome in those with density gradient preparation.CONCLUSION(S): Regurgitation is a common finding during the IUI procedure. We were reassured to find that overall the presence of regurgitation did not decrease the likelihood of pregnancy, as hypothesized. Examining a larger number of IUI cycles will help elucidate the potential effects of regurgitation on pregnancy outcome in specific patient populations. BACKGROUND: Intrauterine insemination (IUI) involves the placement of a small plastic catheter into the uterus via the cervix to inject approximately 0.5ml of concentrated motile sperm. During injection or upon removal of the catheter, we occasionally identify some sample backflow from the cervix, known as regurgitation. We hypothesized the pregnancy rate would be reduced when regurgitation was present. OBJECTIVE(S): The objective of this study was to determine if the presence of regurgitation during IUI affected pregnancy rates. MATERIALS AND METHOD(S): This study was a retrospective chart review of IUIs performed between January 2009 and July 2010. Exclusion criteria included a) two IUIs in the same treatment cycle, b) use of frozen sperm for IUI, c) lack of IUI procedure documentation, or d) partner-reported sample spill. Charts were reviewed for multiple factors known to influence pregnancy rates. Regurgitation was recorded in the procedure note by the physician. The primary outcome measure was a positive pregnancy test. We calculated risk ratios (RR) and 95% confidence intervals (95% CI) using a generalized estimating equation method to estimate Poisson regression models with robust standard errors to account for within-cluster correlation. RESULT(S): From a total of 614 IUI cycles, 25 were excluded, with the remaining 589 cycles available for analysis. These cycles were performed on 257 women (1-7 cycles per patient), an average age of 32. Regurgitation was noted in 265 of 589 procedures (45%). Overall, there was no significant difference in pregnancy rates given presence or absence of regurgitation (16.6% versus 14.8%, respectively; RR 1.16, 95% CI 0.82-1.63). Results were unchanged when adjusted for confounding factors such as age, BMI, days of abstinence, total motile count, progression, agglutination, method of sperm preparation, and IUI difficulty (adjusted RR 1.04, 95% CI 0.71-1.54). However, when stratified by sperm preparation method (density gradient versus “wash only”), the presence of regurgitation decreased the likelihood of pregnancy in the “wash only” group (n= 152 IUIs) when compared to those without regurgitation (1.4% versus 11.0%, respectively; adjusted RR 0.11, 95% CI 0.01-1.07). Regurgitation was not associated with pregnancy outcome in those with density gradient preparation. CONCLUSION(S): Regurgitation is a common finding during the IUI procedure. We were reassured to find that overall the presence of regurgitation did not decrease the likelihood of pregnancy, as hypothesized. Examining a larger number of IUI cycles will help elucidate the potential effects of regurgitation on pregnancy outcome in specific patient populations.