P-116 Clinical predictors of live birth rate (LBR) in donor-intrauterine insemination (D-IUI) cycles
Authors: Band G , Garratt J , Linara-Demakakou E , Macklon N , Ahuja K 
Published: June 2022

Abstract

Study question
Which clinical parameters can predict LBR in D-IUI cycles?

Summary answer
Only age returned as a clinical predictor of D-IUI LBR. Total motile sperm count for insemination (TMSC) and stimulation protocol may help clinicians optimise LBR.

What is known already
D-IUI cycles are a popular treatment option for patients requiring male gamete donation. For both patient and clinician, identification of parameters that can guide clinical decision-making during fertility treatment is important to optimise clinical outcomes. To date, few studies have investigated D-IUI cycle parameters with live birth as the primary outcome. Moreover, previous studies can be limited from lack of control of covariates, as well not accounting for data skewing from inclusion of multiple cycles per patient.

Study design, size, duration
A retrospective analysis of 1925 D-IUI cycles in 638 patients between 2018-2020 at a single UK-based centre was performed. All donors were recruited by the London Sperm Bank as per the HFEA regulations. Inclusion criteria for donor sperm quality were all samples that met the WHO criteria. Exclusion criteria were cycles where live birth outcome was unknown.

Participants/materials, setting, methods
Patients underwent natural or stimulation cycle. Stimulation included clomiphene or letrozole, gonadotrophins +/- GnRH agonist, an hCG trigger or LH-monitoring to time insemination and micronised vaginal progesterone for luteal support. Insemination was scheduled 24 hours following surge detection/trigger administration. TMSC is presented per 0.5ml vial, which is post-preparation sample for insemination. T-test for continuous variables and Fisher’s Exact test for categorical variables were performed. For multivariate analysis, a generalised mixed effects logistic regression was performed.

Main results and the role of chance
Median cohort age was 36 ± SE 0.1, median TMSC was 14x106 ± SE 0.2x106. Of recipients, 53% were same sex couples, 41% were single women, 6.3% were heterosexual couples. There was no significant difference in TMSCs between cycles that produced a live birth and those that did not (14x106 and 13.9x106 respectively, P = 0.1). Dividing TMSC into 5x106 increments demonstrated that small increases in LBR per cycle occurred between 2.5-25x106. On average, LBR increased by 1.3% with each increment up to 25x106, reaching 15%. Beyond this, no further increase in LBR was observed. However, these incremental increases were not statistically significant (P = 0.6). Gonadotrophin stimulation (without agonist) achieved significantly higher LBRs than all other protocols (17.1%, P &lt; 0.001). This persisted when stratifying by age (&lt;35; 30%, 35-37; 29%, 38+; 12.6%). A mixed effects logistic regression model demonstrated that only age returned as a significant negative predictor of LBR (aOR 0.9, 95% CI 0.86-0.94, P &lt; 0.001). There was no effect of TMSC on LBR (aOR 1.0, 95% CI 0.99-1.02, P = 0.7). Gonadotropin stimulation was associated with over double increased odds of achieving a live birth, which came close to significance (aOR 2.29, 95% CI 0.98-5.4, P = 0.06).

Limitations, reasons for caution
The choice of management regimen could have been influenced by uncontrolled factors, introducing bias in this retrospective study. Other semen parameters were not included in the multivariate analyses which could, in turn, have affected live birth outcome, which should be considered.

Wider implications of the findings
These findings demonstrate that increasing TMSC may be associated with small rises in LBR up to 25x106 in D-IUI cycles. While gonadotrophin stimulation appeared most effective, only age was shown to be an independent predictor of LBR. Collectively, these parameters may assist clinicians in optimising LBR in D-IUI cycles.

Trial registration number
None