Comparison of single versus double intrauterine insemination

Optimizing intrauterine insemination: A systematic review and meta-analysis of the effectiveness and safety of clinical treatment add-ons

INTRODUCTION

Intrauterine insemination (IUI) is one of the most widespread fertility treatments. However, IUI protocols vary significantly amongst fertility clinics. Various add-on interventions have been proposed to boost success rates. These are mostly chosen arbitrarily or empirically. The aim of this systematic review and meta-analysis is to assess the effectiveness and safety of add-on interventions to the standard IUI protocol and to provide evidence-based recommendations on techniques used to optimize the clinical outcomes of IUI treatment.

MATERIAL AND METHODS

Systematic review and meta-analyses were performed in accordance with PRISMA guidelines. A computerized literature search was performed from database inception to May 2023. Randomized controlled trials (RCTs) were included reporting on couples/single women undergoing IUI with any protocol for any indication using partner's or donor sperm. A meta-analysis based on random effects was performed for each outcome and add-on. Three authors independently assessed the trials for quality and risk of bias and overall certainty of evidence. Uncertainties were resolved through consensus. Primary outcomes were ongoing pregnancy rate (OPR) or live birth rate (LBR) per cycle/per woman randomized. Registration number PROSPERO: CRD42022300857.

RESULTS

Sixty-six RCTs were included in the analysis (16 305 participants across 20 countries). Vaginal progesterone as luteal phase support in stimulated cycles was found to significantly increase LBR/OPR (RR 1.37, 95% CI 1.09-1.72, I2 = 4.9%) (moderate/low certainty of the evidence). Endometrial scratch prior/during stimulated IUI cycles may increase LBR/OPR (RR 1.44, 95% CI 1.03-2.01, I2 = 1.8%), but evidence is very uncertain. Results from two studies suggest that follicular phase ovarian stimulation increases LBR/OPR (RR 1.39, 95% CI 1.00-1.94, I2 = 0%) (low certainty of evidence). No significant difference was seen for the primary outcome for the other studied interventions.

CONCLUSIONS

The findings of this systematic review and meta-analysis suggest that vaginal luteal phase progesterone support probably improves LBR/OPR in stimulated IUI treatments. In view of moderate/low certainty of the evidence more research is needed for solid conclusions. Further research is also recommended for the use of endometrial scratch and ovarian stimulation. Future studies should report on results according to subfertility background as it is possible that different add-ons could benefit specific patient groups.

Double versus single intrauterine insemination (IUI) in stimulated cycles for subfertile couples

BACKGROUND

In subfertile couples, couples who have tried to conceive for at least one year, intrauterine insemination (IUI) with ovarian hyperstimulation (OH) is one of the treatment modalities that can be offered. When IUI is performed a second IUI in the same cycle might add to the chances of conceiving. In a previous update of this review in 2010 it was shown that double IUI increases pregnancy rates when compared to single IUI. Since 2010, different clinical trials have been published with differing conclusions about whether double IUI increases pregnancy rates compared to single IUI.

OBJECTIVES

To determine the effectiveness and safety of double intrauterine insemination (IUI) compared to single IUI in stimulated cycles for subfertile couples.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility (CGF) Group trials register, CENTRAL, MEDLINE, Embase and CINAHL in July 2020 and LILACS, Google scholar and Epistemonikos in February 2021, together with reference checking and contact with study authors and experts in the field to identify additional studies.

SELECTION CRITERIA

We included randomised controlled, parallel trials of double versus single IUIs in stimulated cycles in subfertile couples.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information.

MAIN RESULTS

We identified in nine studies involving subfertile women. The evidence was of low quality; the main limitations were unclear risk of bias, inconsistent results for some outcomes and imprecision, due to small trials with imprecise results. We are uncertain whether double IUI improves live birth rate compared to single IUI (odds ratio (OR) 1.15, 95% confidence interval (CI) 0.71 to 1.88; I² = 29%; studies = 3, participants = 468; low quality evidence). The evidence suggests that if the chance of live birth following single IUI is 16%, the chance of live birth following double IUI would be between 12% and 27%. Performing a sensitivity analysis restricted to only randomised controlled trials (RCTs) with low risk of selection bias showed similar results. We are uncertain whether double IUI reduces miscarriage rate compared to single IUI (OR 1.78, 95% CI 0.98 to 3.24; I² = 0%; studies = 6, participants = 2363; low quality evidence). The evidence suggests that chance of miscarriage following single IUI is 1.5% and the chance following double IUI would be between 1.5% and 5%. The reported clinical pregnancy rate per woman randomised may increase with double IUI group (OR 1.51, 95% CI 1.23 to 1.86; I² = 34%; studies = 9, participants = 2716; low quality evidence). This result should be interpreted with caution due to the low quality of the evidence and the moderate inconsistency. The evidence suggests that the chance of a pregnancy following single IUI is 14% and the chance following double IUI would be between 16% and 23%. We are uncertain whether double IUI affects multiple pregnancy rate compared to single IUI (OR 2.04, 95% CI 0.91 to 4.56; I² = 8%; studies = 5; participants = 2203; low quality evidence). The evidence suggests that chance of multiple pregnancy following single IUI is 0.7% and the chance following double IUI would be between 0.85% and 3.7%. We are uncertain whether double IUI has an effect on ectopic pregnancy rate compared to single IUI (OR 1.22, 95% CI 0.35 to 4.28; I² = 0%; studies = 4, participants = 1048; low quality evidence). The evidence suggests that the chance of an ectopic pregnancy following single IUI is 0.8% and the chance following double IUI would be between 0.3% and 3.2%.

AUTHORS' CONCLUSIONS

Our main analysis, of which the evidence is low quality, shows that we are uncertain if double IUI improves live birth and reduces miscarriage compared to single IUI. Our sensitivity analysis restricted to studies of low risk of selection bias for both outcomes is consistent with the main analysis. Clinical pregnancy rate may increase in the double IUI group, but this should be interpreted with caution due to the low quality evidence. We are uncertain whether double IUI has an effect on multiple pregnancy rate and ectopic pregnancy rate compared to single IUI.

Single versus double intrauterine insemination (IUI) for pregnancy: A systematic review and meta-analysis

This study is focused in appraising the current evidence comparing double and single IUI for achieving a pregnancy. The primary outcomes were live birth and ectopic pregnancy per women randomized. Secondary outcomes included clinical pregnancy and miscarriage. The evaluation of the risk of bias within each study was structured using the Cochrane risk of bias and the overall quality of the body of evidence was assessed through the GRADE criteria. Electronic searches were run in 4 databases and resulted in 15 studies included encompassing 3795 women. The subgroup 'mild male infertility' included 1246 women whilst the subgroup 'normal semen quality' included 1188 women. Clinical pregnancy was reported by all studies, and there is no evidence of a difference between single and double IUI (RR 1.22, CI 0.97 to 1.54, 15 RCTs, 3795 women, I²=45%). In the subgroup analysis, we could not identify a particular group that could benefit from the intervention. No conclusion can be drawn regarding live birth, ectopic pregnancy, and miscarriage because they were reported by too few studies and the estimates were too imprecise. Currently, there is no evidence to support the use of double IUI in clinical practice. It requires a second appointment and insemination, thus making the treatment more complex and expensive, without a clear evidence of a benefit. Nevertheless, evidence is still of low quality and our confidence in the effect estimate is limited: the true effect may be substantially different from the hereby demonstrated.

The effects of timing of intrauterine insemination in relation to ovulation and the number of inseminations on cycle pregnancy rate in common infertility etiologies

BACKGROUND

Controlled ovarian hyperstimulation with intrauterine insemination (COH/IUI) is an established tool in medically assisted conception for many infertility factors. However, the proper timing of IUI after hCG trigger and the frequency of IUI are still debated. We aimed to examine the association between the cycle pregnancy rate (CPR) and: (i) single IUI timed at 36 ± 2 h post-hCG (pre- or post-ovulation) (ii) the number of IUI (single or double) for pre-ovulatory cases both aims in male, anovulatory and unexplained infertility.

METHODS

The study included a total 1146 first-stimulated cycles in infertile couples due to male factor, anovulation or unexplained infertility. Cycles were stimulated by clomiphine citrate (CC) or sequential CC-hMG or hMG and monitored by transvaginal ultrasound. When the leading follicle reached ≥ 18 mm mean diameter, 10000 IU hCG was given to trigger ovulation and IUI was timed for 36 ± 2 h later. Semen was processed and ovulation was checked at the time of IUI. Post-ovulatory cases received single IUI, while pre-ovulatory cases were sequentially randomized to receive either single or double IUI. The end-point of the cycle was CPR.

RESULTS

Overall CPR in the whole cohort was 10.1%. When ovulation was present before IUI, CPR was 11.7% compared with 6.7% when ovulation was absent [OR (95% CI): 1.85 (1.12-3.06), P = 0.015]. When this OR was computed according to infertility etiology, it was 1.26 (0.52-2.95) (P = 0.82) for male factor infertility and 2.24 (1.23-4.08) (P = 0.007) for non-male factor infertility. Comparing the CPR for double versus single IUI in pre-ovulatory cases, the OR for all cycles was 1.9 (0.76-4.7) (P = 0.22), but according to etiology, it was 4.667 (0.9-24.13) (P = 0.06) in male factor and 1.2 (0.43-3.33) (P = 0.779) for non-male factors.

CONCLUSIONS

Single IUI timed post-ovulation gives a better CPR when compared with single pre-ovulation IUI for non-male infertility, whereas for male factors, pre-ovulation, double IUI gives a better CPR when compared with single IUI.

Intrauterine insemination with husband semen: an evaluation of pregnancy rate and factors affecting outcome

PURPOSE

The aim was to determine pregnancy rate following intrauterine insemination (IUI) and its associated factors in a university assisted reproductive technique center in Tehran, Iran.

METHODS

A retrospective analysis of 350 IUI cycles with ovarian stimulation by clomiphene citrate and/or gonadotropins was performed.

RESULTS

The overall pregnancy rate was 22% (77/350). Of the 77 pregnancies, 88.3% resulted in live birth, 7.8% in spontaneous abortion, 2.6% in blighted ovum and 1.3% were ectopic. Logistic regression analysis revealed three predictive variables as regards pregnancy: number of the treatment cycle (OR:3.5 CI:1.9 - 6.4 p:0.006), duration of infertility (OR:2.1 CI:1.2 - 3.7 p = 0.001) and age (OR:2.15 CI:1.1 - 4.4 p = 0.04). Pregnancy rate did not have any independent relation to sperm count, type of infertility, number and size of follicle and side of ovulatory ovary.

CONCLUSION

Our results indicate that clomiphene citrate and/or gonadotropins IUI is a convenient and useful treatment option in women with younger age ( <30 years) and fewer treatment cycles and fewer infertility duration (4 years).