The definition of unexplained infertility: A systematic review

BACKGROUND

There is no consensus on tests required to either diagnose unexplained infertility or use for research inclusion criteria. This leads to heterogeneity and bias affecting meta-analysis and best practice advice.

OBJECTIVES

This systematic review analyses the variability of inclusion criteria applied to couples with unexplained infertility. We propose standardised criteria for use both in future research studies and clinical diagnosis.

SEARCH STRATEGY

CINAHL and MEDLINE online databases were searched up to November 2022 for all published studies recruiting couples with unexplained infertility, available in full text in the English language.

DATA COLLECTION AND ANALYSIS

Data were collected in an Excel spreadsheet. Results were analysed per category and methodology or reference range.

MAIN RESULTS

Of 375 relevant studies, only 258 defined their inclusion criteria. The most commonly applied inclusion criteria were semen analysis, tubal patency and assessment of ovulation in 220 (85%), 232 (90%), 205 (79.5%) respectively. Only 87/220 (39.5%) studies reporting semen analysis used the World Health Organization (WHO) limits. Tubal patency was accepted if bilateral in 145/232 (62.5%) and if unilateral in 24/232 (10.3%). Ovulation was assessed using mid-luteal serum progesterone in 115/205 (56.1%) and by a history of regular cycles in 87/205 (42.4%). Other criteria, including uterine cavity assessment and hormone profile, were applied in less than 50% of included studies.

CONCLUSIONS

This review highlights the heterogeneity among studied populations with unexplained infertility. Development and application of internationally accepted criteria will improve the quality of research and future clinical care.

Tubal Flushing Treatment for Unexplained Infertility

Tubal patency testing was initially introduced as a diagnostic test. However, it has been observed that some tubal patency tests also have a therapeutic effect. This therapeutic effect can be influenced by the contrast medium used during tubal flushing. In this review, we discuss current evidence associated with different methods for tubal flushing and their potential impact on reproductive outcomes in women with unexplained infertility. Furthermore, we discuss their diagnostic accuracy, safety, and cost-effectiveness.

Effectiveness on fertility outcome of tubal flushing with different contrast media: systematic review and network meta-analysis

OBJECTIVES

To compare, in women with infertility, the effectiveness and safety of tubal flushing using oil-based contrast medium, water-based contrast medium or their combination, and no tubal flushing, and to evaluate the effectiveness of tubal flushing on fertility outcome over time.

METHODS

We performed a systematic review and network meta-analysis, searching the electronic databases MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials, and trial registries, up to 25 September 2018. We included randomized controlled trials (RCTs) comparing the following interventions with each other or with no intervention in women with infertility: tubal flushing using water-based contrast medium, tubal flushing using oil-based contrast medium or additional tubal flushing with oil-based medium following diagnostic tubal flushing with water-based medium. The outcomes included clinical pregnancy, live birth, ongoing pregnancy, miscarriage, ectopic pregnancy and adverse events.

RESULTS

Of the 283 studies identified through the search, 14 RCTs reporting on 3852 women with infertility were included. Network meta-analysis showed that tubal flushing using oil-based contrast medium was associated with higher odds of clinical pregnancy within 6 months after randomization and more subsequent live births compared with tubal flushing using water-based medium (odds ratio (OR), 1.67 (95% CI, 1.38-2.03), moderate certainty of evidence; and OR, 2.18 (95% CI, 1.30-3.65), low certainty of evidence, respectively) and compared with no intervention (OR, 2.28 (95% CI, 1.50-3.47), moderate certainty of evidence; and OR, 2.85 (95% CI, 1.41-5.74), low certainty of evidence, respectively). These results agreed with those of the pairwise meta-analysis. For clinical pregnancy within 6 months, there was insufficient evidence of a difference between tubal flushing with water-based contrast medium and no intervention (OR, 1.36 (95% CI, 0.91-2.04), low certainty of evidence). For fertility outcomes after 6 months, there was insufficient evidence of a difference in any comparison (low to very low certainty of evidence). Compared with tubal flushing using water-based contrast medium, the use of oil-based contrast medium was associated with higher odds of asymptomatic intravasation (OR, 5.06 (95% CI, 2.29-11.18), moderate certainty of evidence).

CONCLUSIONS

In women with infertility undergoing fertility workup, tubal flushing using oil-based contrast medium probably increases clinical pregnancy rates within 6 months after randomization and may increase subsequent live-birth rates, compared with tubal flushing using water-based contrast medium and compared with no intervention. Evidence on fertility outcomes beyond 6 months is inadequate to draw firm conclusions. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Physical endometrial manipulation and its impact on success rate and live birth rate in ICSI in patients with unexplained infertility after recurrent ICSI failure, a double blinded randomized controlled trial

Background: Unexplained infertility is a rising problem and endometrial manipulation could be one of the solutions for enhancing the pregnancy rate and live birth rate in such circumstances.Aims: To evaluate the influence of local endometrial physical manipulation with specializd method for endometrial and tubal hydration (Elgazzar and Alalfy technique) on ICSI outcome and in increasing chemical, clinical, and live birth rate in ICSI after previous recurrent ICSI failure in patients with unexplained infertility.Results: When comparing group 1 (hydrotubation group) and group 2 (the control group with no intervention) with regards to the biochemical, clinical, and live birth rate, the hydrotubation group revealed higher rates and a better ICSI outcome.Conclusion: Hydrotubation is useful in increasing biochemical, clinical, and live birth rates after recurrent failed ICSI trials with a specialized method for hydration of endometrium and tubes (Elgazzar and Alalfy technique).

Hysterosalpingosonography Is Not as Effective as Hysterosalpingography to Increase Chances of Pregnancy

OBJECTIVE

This study sought to examine whether hysterosalpingosonography (sono-HSG) is as effective as hysterosalpingography (HSG) in facilitating conception by comparing pregnancy rates in the 6 months following the procedures.

METHODS

This retrospective noninferiority study (Canadian Task Force classification II-2) was conducted at a tertiary university centre. The investigators studied 440 consecutive eligible infertile women. Bilateral tubal occlusion, severe male infertility, and having undergone both procedures were exclusion criteria. Tubal testing, as part of the infertility workup, was performed by either sono-HSG or HSG. The primary outcome was pregnancy, defined as a positive fetal heartbeat on ultrasonographic examination, in the 6 months following the procedure.

RESULTS

A total of 57 pregnancies (26%) were observed in the HSG group and 33 (15%) in the sono-HSG group. Adjusted and non-adjusted relative risks of pregnancy in the 6 months following sono-HSG compared with HSG were 0.61 (95% CI 0.42-0.89) and 0.58 (95% CI 0.39-0.85). Adverse events were infrequent with both procedures (sono-HSG, 1%; HSG, 4%; P = 0.16).

CONCLUSION

This study suggests that uterine flushing as performed during sono-HSG is not as effective as when performed during HSG to increase the chances of pregnancy, but further studies will be required because of bias related to the retrospective study design.

Uterine contractility changes in a perfused swine uterus model induced by local anesthetics procaine, lidocaine, and ropivacaine

Background

Local anesthetics (LAs) are increasingly used as therapeutics due to their multiple molecular effects. They may be potential agents also in gynecology and reproductive medicine. The objective of this study was to investigate the contractility response of the perfused swine uterus to different concentrations of the LAs procaine, lidocaine, and ropivacaine.

Methods and findings

In an extracorporeal perfusion model with fresh swine uteri, effects of administered boli of these three LAs in concentrations of 0.1 mg/mL, 0.5 mg/mL and 1.0 mg/mL on uterine contractility and peristalsis were assessed using an intrauterine double-chip micro-catheter. A dose-dependent increase in intrauterine pressure (IUP) in the isthmus and corpus uteri was observed after the administration of the ester-LA procaine 0.1, 0.5, and 1.0%, which was not seen with lower concentrations, or buffer solution. An increase-decrease curve was found after increasing concentrations of the amide-LA lidocaine and ropivacaine, with an IUP plateau with 0.1 and 0.5%, and a decrease with 1% (p<0.01). All reactions were seen in both the isthmus and corpus uteri. The difference of the contractility pattern between ester- and amide-LA at 1% concentration was significant.

Conclusion

LAs dose-dependently modulate contractility in non-pregnant swine uteri. The amid-LAs lidocaine and ropivacaine reduce contractility in higher concentrations and may be used as therapeutics in disorders with increased uterine contractility, as dysmenorrhoea, endometriosis, and infertility. The multiple molecular effects of LAs may explain these effects. This in-vitro pilot study in vitro provides initial data for designing further studies to transfer the results onto humans.

Effect of Lignocaine on IL-6, IL-8, and MCP-1 in Peritoneal Macrophages and Endometriotic Stromal Cells

OBJECTIVE

The objective was to evaluate the effect of lignocaine on cytokine expression and secretion in vitro in peritoneal fluid macrophages and endometriotic stromal cells.

DESIGN

Experimental in vitro study on human cells.

POPULATION AND SAMPLE

Peritoneal fluid (n = 10) and samples from endometriotic cysts (n = 7) were collected from 13 women (women with endometriosis n = 8, and healthy controls n = 5) during surgery for clinical reasons.

METHODS

Macrophages from the peritoneal fluid and cells from the inside of the endometriotic cysts capsules were isolated and cultivated for 24 to 48 hours in medium with and without the supplement of lignocaine 0.1 or 1.0 mg/mL. Relative gene expression of monocyte chemotactic protein 1 (MCP-1), interleukin 6 (IL-6), and IL-8 was evaluated with quantitative polymerase chain reaction and compared between treated and untreated cells with Wilcoxon matched pairs. The concentrations of MCP-1, IL-6, and IL-8 were measured using enzyme-linked immunosorbent assay and were compared between treated and untreated cells with Wilcoxon matched pairs.

RESULTS

The gene expression and protein secretion of IL-8 in endometriotic stromal cells after incubation with lignocaine 0.1 mg/mL were significantly decreased after 24 hours compared to the controls ( P = .028 and P = .018). Macrophages from healthy controls had a significant lower gene expression of all tested cytokines ( P = .043) after treatment with lignocaine, but there were no significant differences in protein level. Macrophages from women with endometriosis showed diverging results since 3 of 5 samples showed increased gene expression of 1 (n = 2) or 2 cytokines (n = 1) after lignocaine treatment.

CONCLUSION

Lignocaine can affect the gene expression and secretion of some proinflammatory cytokines in vitro.

Preovulatory uterine flushing with saline as a treatment for unexplained infertility: a randomised controlled trial protocol

INTRODUCTION

In vitro fertilisation (IVF) is the treatment of choice for unexplained infertility. Preovulatory uterine flushing could reduce intrauterine debris and inflammatory factors preventing pregnancy and constitute an alternative to IVF. Our objective is to assess the efficacy of preovulatory uterine flushing with physiological saline for the treatment of unexplained infertility.

METHODS AND ANALYSIS

We will perform a randomised controlled trial based on consecutive women aged between 18 and 37 years consulting for unexplained infertility for at least 1 year. On the day of their luteinising hormone surge, 192 participants will be randomised in two equal groups to either receive 20 mL of physiological saline by an intrauterine catheter or 10 mL of saline intravaginally. We will assess relative risk of live birth (primary outcome), as well as pregnancy (secondary outcome) over one cycle of treatment. We will report the side effects, complications and acceptability of the intervention.

ETHICS AND DISSEMINATION

This project was approved by the Ethics committee of the Centre Hospitatlier Universitaire de Quebec (no 2015-1146). Uterine flushing is usually well tolerated by women and would constitute a simple, affordable and minimally invasive treatment for unexplained infertility. We plan to communicate the results of the review by presenting research abstracts at conferences and by publishing the results in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT02539290; Pre-results.

Serum concentration of lignocaine after pertubation: an observational study

Objective

The objective of this study was to report the serum concentration of lignocaine after pertubation in patients with endometriosis.

Design

Prospective observational study.

Setting

The study was carried out at a gynaecological outpatient unit in Stockholm, Sweden.

Population

Eligible patients had endometriosis with a dysmenorrhoic pain score of >50 mm on a visual analogue scale, and patent fallopian tubes.

Methods

Patients with endometriosis (n = 25) were included in the study. The patients received pre-ovulatory pertubations with lignocaine hydrochloride 10 mg (n = 16) or ringer acetate (placebo, n = 9). The procedure comprised passing the study solution through the uterus and the fallopian tubes via an intra-cervical balloon catheter. Serum samples were collected at 0, 5, 15 and 30 min after pertubation.

Main Outcome Measures

The serum samples were analysed for the concentration of lignocaine with an LCMS-SIM method.

Results

Low levels of lignocaine were detected in the serum samples following pertubation of 10 mg lignocaine hydrochloride. The highest observed concentration was seen after 30 min (mean 0.050 μg/ml), with an individual maximum of 0.124 μg/ml. Maximum concentration (C_max) and time to C_max (T_max) could not be calculated, since the highest values were observed in the 30-min samples, which was the last sample obtained. Lignocaine was not detected after pertubation with placebo.

Conclusions

The serum levels of lignocaine following pertubation of 10 mg lignocaine hydrochloride are detectable but low. Lignocaine pertubated through the fallopian tubes reaches the peritoneal cavity and diffuses through the peritoneum into the blood circulation. Pertubation with lignocaine is safe and has no lignocaine-related adverse events.