Related influencing factors of intrauterine insemination pregnancy outcomes: a retrospective cohort study of 26 473 cycles in single center for 10 years

Abstract

Objective To investigate the influencing factors the pregnancy outcomes of intrauterine insemination (IUI). Methods From January 2007 to June 2017, a total of 26 473 artificial insemination by husband (AIH) and artificial insemination by donor (AID) cycles of 12 165 couples in the Department of Reproductive Medicine, the First Affiliated Hospital of Nanjing Medical University/Jiangsu Province Hospital were retrospectively analyzed, and the data came from the Center’s Clinical Assisted Reproductive Technology Management (CCRM) system database version 15.2. The relationship of pregnancy outcomes to the female age, the male age, the number of cycles, the duration of infertility, infertility types, the cause of infertility, treatment regimens, the timing of insemination was studied. Results 1) In AIH, the live birth rate (LBR) (4.16%) of women aged≥37 years was significantly lower than those of <37 years old (9.58%, P<0.001), and there was no pregnancy when their husbands aged 45 years or older. After 3 AIH cycles, the cumulative live birth rate (CLBR) and clinical pregnancy rate (CCPR) were no longer significantly increased. If the woman was younger than 37 years old, no matter the primary or secondary infertility patients, the LBR was significantly lower in patients with more than 5 years of infertility (8.03%, 5.75%) than those less than 5 years (9.96%, P<0.001; 10.91%, P<0.001). The LBR of ovulatory disorder and sexual dysfunction group (13.24%, 17.66%) was significantly higher than that of mild oligospermia and asthenospermia (7.04%), tubal factor (6.62%), endometriosis (7.13%) and unexplained infertility (7.75%) (all P<0.001). Clomiphene (CC) or letrozole (LE) combined with gonadotropin (Gn) could achieve higher LBR (12.20%, 12.52%) than natural cycle (7.58%) or CC/LE/hMG used alone (8.14%, 6.82%, 7.82%, P<0.001). The LBR of pre-ovulation insemination in the stimulation cycle (10.29%) was higher than that of post-ovulation insemination (8.13%, P=0.034). 2) In AID, infertility type, treatment regimen and the timing of insemination had no significantly effect on pregnancy outcome. The abortion rate of women aged≥37 years (37.5%) was significantly higher than that of <37 years old (11.44%, P<0.001). After 4 AID cycles, the CLBR was no longer significantly increased. The LBR of CC+Gn regimen was similar to that of LE+Gn regimen (21.04%, 20.12%), but multiple LBR of LE+Gn regimen (4.80%) significantly reduced (12.03%, P=0.012). Conclusion No matter AIH or AID, the female age is the most important factor influencing the pregnancy outcome. Furthermore, the influence of infertility duration, the male age and the cause of infertility on the pregnancy outcome must be considered simultaneously in AIH. LE+Gn regimen can significantly increase the LBR and diminish the risk of multiple pregnancy compared with CC+Gn. Key words: Insemination; Age factor; Cumulative live birth rate; Infertility duration; Letrozole