Cumulative livebirth rates (CLBR) in intrauterine insemination (IUI) using donor's sperm related to women's age: a retrospective study in 7.122 cases

Abstract

OBJECTIVE: The aim of this study was to describe the cumulative livebirth rates (CLBR) in IUI cycles using donor sperm, also evaluating the influence of women's age on the results. DESIGN: Retrospective cohorts study. MATERIALS AND METHODS: We analyzed 7.122 donor IUI cycles underwent on 3137 patients from 1998 to 2009. CLBR and 95% confidence intervals (CI) were estimated by Kaplan–Meier method and curves according to the cycle number. Tarone-Ware and Breslow tests used to compare among curves. Data were analyzed globally, and stratified according to 5 different women's age groups (20-29, 30-34, 35-37, 38-39, 40-45). All women showed a normal fertility work-up including hysterosalpingography. Sperm preparation was performed by density gradient. RESULTS: Overall results showed 26.8%(CI25.8-27.8) of pregnancy rate, 20.4%(CI19.5-21.3) of livebirth rate and 12.9%(CI11.4-14.4) of multiple pregnancy rate. The CLBR increased progressively, from 22.6%(CI21.1-24.1) in the 1st, 38.4%(CI36.5-40.2) in the 2nd, 48.9%(CI46.8-51.0) in the 3rd, 72.6%(CI69.3-75.8) in the 6th and reaching plateau in the 8th cycle (81.2%(CI75.9-86.6). We confirmed an age-related decrease in the success rates, observing a significant decrease in women aged 38-39 from the 1st (14.5%(CI11.1-17.9)), 2nd (26.3%(CI21.6-30.1)), 3rd (35.9%(CI30.3-41.5)), and reaching plateau after the 6th cycle (59.4%(CI4.1-71.7)). This age related effect was more dramatic in women aged 40-45, where only (6.4%(CI3.9-8.9)) in the 1st, (13.9%(CI9.9-17.9)) in the 2nd, (21.2%(CI15.7-26.6)) in the 3rd, and reaching the maximum level in the 5th cycle, with only (36.6%(CI25.9-47.3)) CLBR. CONCLUSION: CLBR provide representative information about the expected success after donor IUI, in order to counsel patients and practitioners about the adequacy of repeating a cycle after failure, or changing to complex assisted reproduction techniques such as IVF. Prognosis decreased significantly in women older than 37, being more important above 40 years old.