Techniques for preparation prior to embryo transfer

Antibiotics prior to or at the time of embryo transfer in ART

BACKGROUND

After an assisted reproductive technology (ART) cycle, embryo transfer (ET) involves the placement of one or more embryos into the uterine cavity, usually by passing a catheter through the cervical os. Despite the transfer of high-quality embryos, many ETs do not result in a pregnancy. There are many factors that may affect the success of ET. There is some evidence to suggest that increased endocervical microbial colonization at the time of ET results in lower pregnancy rates. The association between the cervico-vaginal microbiome and reduced pregnancy rates after ET may indicate either pre-existing dysbiosis in this patient population, or that the passage of the ET catheter itself may be introducing microbes that alter the microbiome of the endometrial cavity or lead to infection. Such an upper genital tract infection, contamination or alteration may have a negative impact on implantation and in vitro fertilization (IVF) success rates by both endometrial and embryonic mechanisms. The administration of antibiotics at the time of ET has been suggested as an intervention to reduce levels of microbial colonization and hence improve pregnancy rates.

OBJECTIVES

To evaluate the benefits and harms of antibiotic administration prior to or at the time of embryo transfer (ET) during assisted reproductive technology (ART) cycles.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility (CGF) Group trials register, CENTRAL (now containing output from two trial registers and CINAHL), MEDLINE, Embase and PsycINFO, together with reference checking and contact with study authors and experts in the field to identify additional studies. The search date was November 2022.

SELECTION CRITERIA

We included two randomized controlled trials (RCT) that compared antibiotics administered by any route versus no antibiotics prior to ET.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane, including assessing risk of bias of the included studies using the RoB 2 tool. The primary review outcome was live birth rate (LBR) or ongoing pregnancy, and secondary outcomes were clinical pregnancy rate (CPR), genital tract colonization rate, miscarriage rate, ectopic pregnancy rate, multiple pregnancy rate, fetal abnormalities, adverse events and pelvic infection.

MAIN RESULTS

We included two RCTs with 377 women in the review. Using the GRADE method, we assessed the certainty of the evidence as very low to low across measured outcomes. We are uncertain whether antibiotics given prior to or at the time of ET improved LBR (odds ratio (OR) 0.48, 95% confidence interval (CI) 0.10 to 2.23; 1 study, 27 women; low-certainty evidence). The evidence suggests that if LBR without antibiotics was 60%, the rate with antibiotics would be between 13% and 77%. We are uncertain whether antibiotics given prior to or at the time of ET improve CPR (OR 1.01, 95% CI 0.67 to 1.55; I² = 0%; 2 studies, 377 women; low-certainty evidence). If the CPR without antibiotics was 37%, the rate with antibiotics would be between 29% and 48%. The administration of antibiotics prior to or at the time of ET may reduce genital tract colonization slightly (OR 0.59, 95% CI 0.37 to 0.95; 1 study, 130 women; very low-certainty evidence). If the genital tract colonization rate without antibiotics was 29%, the rate with antibiotics would be between 13% and 28%. However, this did not correspond to an effect on the pregnancy outcome. Only one study with low numbers of women reported on miscarriage rate, with one miscarriage reported in the group not receiving antibiotics (OR 4.04, 0.15 to 108.57; 1 study, 27 women; low-certainty evidence). There was insufficient evidence to reach a conclusion regarding adverse effects and other outcomes as no studies reported data suitable for analysis.

AUTHORS' CONCLUSIONS

We are uncertain if administration of antibiotics prior to or at the time of ET improves LBR in women undergoing ART based on a single study of 27 women with low-certainty evidence. We are uncertain whether there was a difference in CPR. There was evidence for a reduction in genital tract colonization rates, but the evidence was very low certainty. Data were lacking on other secondary outcomes. The pooled results should be interpreted with caution, due to the small number of women included in the analysis.

Comparison of pregnancy outcomes of cervical mucus washing with physiologic saline solution or G-Rinse medium solution, in elective single-embryo transfers

AIM

To compare the pregnancy outcomes between physiologic saline and G-Rinse medium solution for cervical mucus washing, in fresh elective single-embryo transfers (ET) in women under the age of 37.

MATERIAL AND METHODS

This was a retrospective data analysis performed in a single in vitro fertilization (IVF) center between February 2018 and November 2021. Women younger than 37 years who underwent single elective ET were included and all women had anti-Mullerian hormone (AMH) levels ≥ 1.5 ng/ml. Age, body mass index (BMI), AMH levels, and pregnancy outcomes as clinical pregnancy rate (CPR) and live birth rate (LBR) were analyzed.

RESULTS

Study population consisted of 75 women in the G-Rinse medium solution group and 97 women in the physiologic saline group. Clinical pregnancy rate was 58.7% and 61.9% in the G-Rinse medium solution group and saline group, respectively (p = 0.673), and LBR was calculated as 41.3% and 47.4% in the G-Rinse medium solution group and saline group, respectively (p = 0.430). A log-binomial regression model was used and the model was adjusted for BMI to evaluate the effect of the cervical mucus washing method on the pregnancy outcomes. There was an estimated 5% decrease in the relative risk for CPR in the G-Rinse medium solution group compared to the saline group (95% CI: 0.74 to 1.2, p = 0.673). There was an estimated 13% reduction in the relative risk for LBR in the G-Rinse medium solution group compared to the saline group (95% CI: 0.62 to 1.23, p = 0.430). They were both statistically not significant.

CONCLUSION

In our study, the replacement of using G-Rinse medium solution to physiologic saline solution for cervical cleaning did not change CPR and LBR outcomes. Using physiologic saline solution can be a good alternative approach for ectocervical washing during embryo transfer in selected population because of its lower costs, easy accessibility, and common use.

Oxytocin antagonists for assisted reproduction

BACKGROUND

Embryo transfer (ET) is a crucial step of in vitro fertilisation (IVF) treatment, and involves placing the embryo(s) in the woman's uterus. There is a negative association between endometrial wave-like activity (contractile activities) at the time of ET and clinical pregnancy, but no specific treatment is currently used in clinical practice to counteract their effects. Oxytocin is a hormone produced by the hypothalamus and released by the posterior pituitary. Its main role involves generating uterine contractions during and after childbirth. Atosiban is the best known oxytocin antagonist (and is also a vasopressin antagonist), and it is commonly used to delay premature labour by halting uterine contractions. Other oxytocin antagonists include barusiban, nolasiban, epelsiban, and retosiban. Administration of oxytocin antagonists around the time of ET has been proposed as a means to reduce uterine contractions that may interfere with embryo implantation. The intervention involves administering the medication before, during, or after the ET (or a combination).

OBJECTIVES

To evaluate the effectiveness and safety of oxytocin antagonists around the time of ET in women undergoing assisted reproduction.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility (CGF) Group trials register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and two trials registers in March 2021; and checked references and contacted study authors and experts in the field to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of the use of oxytocin antagonists for women undergoing ET, compared with the non-use of this intervention, the use of placebo, or the use of another similar drug.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. Primary review outcomes were live birth and miscarriage; secondary outcomes were clinical pregnancy and other adverse events.

MAIN RESULTS

We included nine studies (including one comprising three separate trials, 3733 women analysed in total) investigating the role of three different oxytocin antagonists administered intravenously (atosiban), subcutaneously (barusiban), or orally (nolasiban). We found very low- to high-certainty evidence: the main limitations were serious risk of bias due to poor reporting of study methods, and serious or very serious imprecision. Intravenous atosiban versus normal saline or no intervention We are uncertain of the effect of intravenous atosiban on live birth rate (risk ratio (RR) 1.05, 95% confidence interval (CI) 0.88 to 1.24; 1 RCT, N = 800; low-certainty evidence). In a clinic with a live birth rate of 38% per cycle, the use of intravenous atosiban would be associated with a live birth rate ranging from 33.4% to 47.1%. We are uncertain whether intravenous atosiban influences miscarriage rate (RR 1.08, 95% CI 0.75 to 1.56; 5 RCTs, N = 1424; I² = 0%; very low-certainty evidence). In a clinic with a miscarriage rate of 7.2% per cycle, the use of intravenous atosiban would be associated with a miscarriage rate ranging from 5.4% to 11.2%. Intravenous atosiban may increase clinical pregnancy rate (RR 1.50, 95% CI 1.18 to 1.89; 7 RCTs, N = 1646; I² = 69%; low-certainty evidence), and we are uncertain whether multiple or ectopic pregnancy and other complication rates were influenced by the use of intravenous atosiban (very low-certainty evidence). Subcutaneous barusiban versus placebo One study investigated barusiban, but did not report on live birth or miscarriage. We are uncertain whether subcutaneous barusiban influences clinical pregnancy rate (RR 0.96, 95% CI 0.69 to 1.35; 1 RCT, N = 255; very low-certainty evidence). Trialists reported more mild to moderate injection site reactions with barusiban than with placebo, but there was no difference in severe reactions. They reported no serious drug reactions; and comparable neonatal outcome between groups. Oral nolasiban versus placebo Nolasiban does not increase live birth rate (RR 1.13, 95% CI 0.99 to 1.28; 3 RCTs, N = 1832; I² = 0%; high-certainty evidence). In a clinic with a live birth rate of 33% per cycle, the use of oral nolasiban would be associated with a live birth rate ranging from 32.7% to 42.2%. We are uncertain of the effect of oral nolasiban on miscarriage rate (RR 1.45, 95% CI 0.73 to 2.88; 3 RCTs, N = 1832; I² = 0%; low-certainty evidence). In a clinic with a miscarriage rate of 1.5% per cycle, the use of oral nolasiban would be associated with a miscarriage rate ranging from 1.1% to 4.3%. Oral nolasiban improves clinical pregnancy rate (RR 1.15, 95% CI 1.02 to 1.30; 3 RCTs, N = 1832; I² = 0%; high-certainty evidence), and probably does not increase multiple or ectopic pregnancy, or other complication rates (moderate-certainty evidence).

AUTHORS' CONCLUSIONS

We are uncertain whether intravenous atosiban improves pregnancy outcomes for women undergoing assisted reproductive technology. This conclusion is based on currently available data from seven RCTs, which provided very low- to low-certainty evidence across studies. We could draw no clear conclusions about subcutaneous barusiban, based on limited data from one RCT. Further large well-designed RCTs reporting on live births and adverse clinical outcomes are still required to clarify the exact role of atosiban and barusiban before ET. Oral nolasiban appears to improve clinical pregnancy rate but not live birth rate, with an uncertain effect on miscarriage and adverse events. This conclusion is based on a phased study comprising three trials that provided low- to high-certainty evidence. Further large, well-designed RCTs, reporting on live births and adverse clinical outcomes, should focus on identifying the subgroups of women who are likely to benefit from this intervention.

National Survey Highlights the Urgent Need for Standardisation of Embryo Transfer Techniques in the UK

Embryo transfer (ET) is one of the vital steps in the in vitro fertilisation (IVF) process, yet there is wide variation in ET technique throughout the UK, without a nationally approved standardised approach. The aim of this study was to gain contemporaneous information regarding the current clinical ET practice in the UK.

METHOD

A 38-question electronic survey was distributed to the 79 UK Human Fertilisation and Embryology Authority (HFEA) registered clinics performing ETs.

RESULTS

In total, 59% (47/79) of units responded, 83% (39/47) performing ultrasound-guided transfers, with 42% (20/47) of units using a tenaculum; 22% (10/45) would proceed with transfer regardless of fluid in the endometrial cavity. In 91% (43/47) of units, embryos were deposited in the upper/middle portion of the uterine cavity, but interpretation of this area ranged from 0.5 to >2 cm from the fundus, with 68% (32/47) allowing patients to mobilise immediately after transfer. In 60% (27/45) of clinics, success rates were based on clinical pregnancy rates (CPR).

CONCLUSION

Within the UK there is a wide range of variability in ET techniques, with >70% of discordance in survey-responses between clinics. Whilst there are areas of good practice, some disadvantageous techniques continue to persist. This survey emphasises the importance of developing a standardised, evidence-based approach to improve ET success rates.

Temperature of embryo culture for assisted reproduction

BACKGROUND

'Infertility' is defined as the failure to achieve pregnancy after 12 months or more of regular unprotected sexual intercourse. One in six couples experience a delay in becoming pregnant. In vitro fertilisation (IVF) is one of the assisted reproductive techniques used to enable couples to achieve a live birth. One of the processes involved in IVF is embryo culture in an incubator, where a stable environment is created and maintained. The incubators are set at approximately 37°C, which is based on the human core body temperature, although several studies have shown that this temperature may in fact be lower in the female reproductive tract and that this could be beneficial. In this review we have included randomised controlled trials which compared different temperatures of embryo culture.

OBJECTIVES

To assess different temperatures of embryo culture for human assisted reproduction, which may lead to higher live birth rates.

SEARCH METHODS

We searched the following databases and trial registers: the Cochrane Gynaecology and Fertility (CGF) Group Specialised Register of Controlled Trials, the Cochrane Central Register of Studies Online, MEDLINE, Embase, PsycINFO, CINAHL, clinicaltrials.gov, The World Health Organization International Trials Registry Platform search portal, DARE, Web of Knowledge, OpenGrey, LILACS database, PubMed and Google Scholar. Furthermore, we manually searched the references of relevant articles and contacted experts in the field to obtain additional data. We did not restrict the search by language or publication status. We performed the last search on 6 March 2019.

SELECTION CRITERIA

Two review authors independently screened the titles and abstracts of articles retrieved by the search. Full texts of potentially eligible randomised controlled trials (RCTs) were obtained and screened. We included all RCTs which compared different temperatures of embryo culture in IVF or intracytoplasmic sperm injection (ICSI), with a minimum difference in temperature between the two incubators of ≥ 0.5°C. The search process is shown in the PRISMA flow chart.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and risk of bias and extracted data from the included studies; the third review author resolved any disagreements. We contacted trial authors to provide additional data. The primary review outcomes were live birth and miscarriage. Clinical pregnancy, ongoing pregnancy, multiple pregnancy and adverse events were secondary outcomes. All extracted data were dichotomous outcomes, and odds ratios (OR) were calculated with 95% confidence intervals (CIs) on an intention-to-treat basis. We assessed the overall quality of the evidence for the main comparisons using GRADE methods.

MAIN RESULTS

We included three RCTs, with a total of 563 women, that compared incubation of embryos at 37.0°C or 37.1°C with a lower incubator temperature (37.0°C versus 36.6°C, 37.1°C versus 36.0°C, 37.0° versus 36.5°C). Live birth, miscarriage, clinical pregnancy, ongoing pregnancy and multiple pregnancy were reported. After additional information from the authors, we confirmed one study as having no adverse events; the other two studies did not report adverse events. We did not perform a meta-analysis as there were not enough studies included per outcome. Live birth was not graded since there were no data of interest available. The evidence for the primary outcome, miscarriage, was of very low quality. The evidence for the secondary outcomes, clinical pregnancy, ongoing pregnancy and multiple pregnancy was also of very low quality. We downgraded the evidence because of high risk of bias (for performance bias) and imprecision due to limited included studies and wide CIs.Only one study reported the primary outcome, live birth (n = 52). They performed randomisation at the level of oocytes and not per woman, and used a paired design whereby two embryos, one from 36.0°C and one from 37.0°C, were transferred. The data from this study were not interpretable in a meaningful way and therefore not presented. Only one study reported miscarriage. We are uncertain whether incubation at a lower temperature decreases the miscarriage (odds ratio (OR) 0.90, 95% CI 0.52 to 1.55; 1 study, N = 412; very low-quality evidence).Of the two studies that reported clinical pregnancy, only one of them performed randomisation per woman. We are uncertain whether a lower temperature improves clinical pregnancy compared to 37°C for embryo incubation (OR 1.08, 95% CI 0.73 to 1.60; 1 study, N = 412; very low-quality evidence). For the outcome, ongoing pregnancy, we are uncertain if a lower temperature is better than 37°C (OR 1.10, 95% CI 0.75 to 1.62; 1 study, N = 412; very low quality-evidence). Multiple pregnancy was reported by two studies, one of which used a paired design, which made it impossible to report the data per temperature. We are uncertain if a temperature lower than 37°C reduces multiple pregnancy (OR 0.80, 95% CI 0.31 to 2.07; 1 study, N = 412; very low-quality evidence). There was insufficient evidence to make a conclusion regarding adverse events, as no studies reported data suitable for analysis.

AUTHORS' CONCLUSIONS

This review evaluated different temperatures for embryo culture during IVF. There is a lack of evidence for the majority of outcomes in this review. Based on very low-quality evidence, we are uncertain if incubating at a lower temperature than 37°C improves pregnancy outcomes. More RCTs are needed for comparing different temperatures of embryo culture which require reporting of clinical outcomes as live birth, miscarriage, clinical pregnancy and adverse events.

Intrauterine administration of human chorionic gonadotropin (hCG) for subfertile women undergoing assisted reproduction

BACKGROUND

Most women undergoing assisted reproduction treatment will reach the stage of embryo transfer (ET), but the proportion of embryos that can be successfully implanted after ET has remained small since the mid-1990s. Human chorionic gonadotropin (hCG) is a hormone that is synthesised and released by the syncytiotrophoblast and has a fundamental role in embryo implantation and the early stages of pregnancy. Intrauterine administration of hCG via ET catheter during a mock procedure around the time of ET is a novel approach that has been suggested to improve the outcomes of assisted reproduction.

OBJECTIVES

To investigate whether intrauterine (intracavity) administration of hCG (IC-hCG) around the time of ET improves clinical outcomes in subfertile women undergoing assisted reproduction.

SEARCH METHODS

We performed searches on 9 January 2018 using Cochrane methods.

SELECTION CRITERIA

We looked for randomised controlled trials (RCTs) evaluating IC-hCG around the time of ET, irrespective of language and country of origin.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed risk of bias, extracted data from studies, and attempted to contact study authors when data were missing. We performed statistical analysis using Review Manager 5. We assessed evidence quality using GRADE methods. Primary outcomes were live birth and miscarriage; secondary outcomes were clinical pregnancy rate and complications.

MAIN RESULTS

Seventeen RCTs investigated the effects of IC-hCG administration for 4751 subfertile women undergoing assisted reproduction. IC-hCG was administered in variable doses at different times before the ET. hCG was obtained from the urine of pregnant women or from cell cultures using recombinant DNA technology.Most studies (12/17) were at high risk of bias in at least one of the seven domains assessed. Common problems were unclear reporting of study methods and lack of blinding. The main limitations for evidence quality were high risk of bias and serious imprecision.For analyses of live birth and clinical pregnancy, there was considerable heterogeneity (I² > 75%) and therefore we present subgroups for dosage and stage of ET. Exploration for sources of heterogeneity revealed two key prespecified variables as important determinants: stage of ET (cleavage vs blastocyst stage) and dose of IC-hCG (< 500 international units (IU) vs ≥ 500 IU). We performed meta-analyses within subgroups defined by stage of embryo and dose of IC-hCG.Live birth rates among women having cleavage-stage ET with an IC-hCG dose < 500 IU compared to women having cleavage-stage ET without IC-hCG showed no benefit of the intervention and would be consistent with no substantive difference or disadvantage of indeterminate magnitude (risk ratio (RR) 0.76, 95% confidence interval (CI) 0.58 to 1.01; one RCT; 280 participants; I² = 0%; very low-quality evidence). In a clinic with a live birth rate of 49% per cycle, use of IC-hCG < 500 IU would be associated with a live birth rate ranging from 28% to 50%.Results show an increase in live birth rate in the subgroup of women undergoing cleavage-stage ET with an IC-hCG dose ≥ 500 IU compared to women having cleavage-stage ET without IC-hCG (RR 1.57, 95% CI 1.32 to 1.87; three RCTs; 914 participants; I² = 0%; moderate-quality evidence). At a clinic with a live birth rate of 27% per cycle, use of IC-hCG ≥ 500 IU would be associated with a live birth rate ranging from 36% to 51%.Results show no substantive differences in live birth among women having blastocyst-stage ET with an IC-hCG dose ≥ 500 IU compared to women having blastocyst-stage ET without IC-hCG (RR 0.92, 95% CI 0.80 to 1.04; two RCTs; 1666 participants; I² = 0%; moderate-quality evidence). At a clinic with a live birth rate of 36% per cycle, use of IC-hCG ≥ 500 IU would be associated with a live birth rate ranging from 29% to 38%.Evidence for clinical pregnancy among women having cleavage-stage ET with an IC-hCG dose < 500 IU showed no benefit of the intervention and would be consistent with no substantive difference or disadvantage of indeterminate magnitude (RR 0.88, 95% CI 0.70 to 1.10; one RCT; 280 participants; I² = 0%; very low-quality evidence).Results show an increase in clinical pregnancy rate in the subgroup of women having cleavage-stage ET with an IC-hCG dose ≥ 500 IU compared to women having cleavage-stage ET without IC-hCG (RR 1.49, 95% CI 1.32 to 1.68; 12 RCTs; 2186 participants; I² = 18%; moderate-quality evidence).Results show no substantive differences in clinical pregnancy among women having blastocyst-stage ET with an IC-hCG dose ≥ 500 IU (RR 0.99, 95% CI 0.85 to 1.15; four RCTs; 2091 participants; I² = 42%; moderate-quality evidence) compared to women having blastocyst-stage ET with no IC-hCG.No RCTs investigated blastocyst-stage ET with an IC-hCG dose < 500 IU.We are uncertain whether miscarriage was influenced by intrauterine hCG administration (RR 1.04, 95% CI 0.81 to 1.35; 11 RCTs; 3927 participants; I² = 0%; very low-quality evidence).Reported complications were ectopic pregnancy (four RCTs; 1073 participants; four events overall), heterotopic pregnancy (one RCT; 495 participants; one event), intrauterine death (three RCTs; 1078 participants; 22 events), and triplets (one RCT; 48 participants; three events). Events were few, and very low-quality evidence was insufficient to permit conclusions to be drawn.

AUTHORS' CONCLUSIONS

There is moderate quality evidence that women undergoing cleavage-stage transfer using an IC-hCG dose ≥ 500 IU have an improved live birth rate. There is insufficient evidence for IC-hCG treatment for blastocyst transfer. There should be further trials with live birth as the primary outcome to identify the groups of women who would benefit the most from this intervention. There was no evidence that miscarriage was reduced following IC-hCG administration, irrespective of embryo stage at transfer or dose of IC-hCG. Events were too few to allow conclusions to be drawn with regard to other complications.

Assisted reproductive technology: an overview of Cochrane Reviews

BACKGROUND

As many as one in six couples will encounter problems with fertility, defined as failure to achieve a clinical pregnancy after regular intercourse for 12 months. Increasingly, couples are turning to assisted reproductive technology (ART) for help with conceiving and ultimately giving birth to a healthy live baby of their own. Fertility treatments are complex, and each ART cycle consists of several steps. If one of these steps is incorrectly applied, the stakes are high as conception may not occur. With this in mind, it is important that each step of the ART cycle is supported by good evidence from well-designed studies.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on procedures and treatment options available to couples with subfertility undergoing assisted reproductive technology (ART) procedures.

METHODS

Published Cochrane systematic reviews of couples undergoing ART procedures (in vitro fertilisation or intracytoplasmic sperm injection) were eligible for inclusion in the overview. We also identified Cochrane reviews in preparation, for future inclusion.The primary outcome of the overview was live birth or the composite outcome live birth or ongoing pregnancy, as reported by the included reviews. Our secondary outcomes were clinical pregnancy, multiple pregnancy, miscarriage, and ovarian hyperstimulation syndrome. We excluded studies of intrauterine insemination and ovulation induction.We undertook selection of systematic reviews, data extraction, and quality assessment in duplicate. We assessed review quality by using the AMSTAR tool. We organised reviews by their relevance to specific stages in the ART cycle. We summarised their findings in the text and reported data for each outcome in 'Additional tables'.

MAIN RESULTS

We included 68 systematic reviews published in the Cochrane Library up to May 2018. All were of high quality. These reviews identified 38 interventions that were effective (n = 23) or promising (n = 15), and they identified 19 interventions that were ineffective (n = 2) or possibly ineffective (n = 17). For 15 interventions, review authors were unable to draw conclusions owing to lack of evidence.We identified an additional 11 protocols and four titles for future inclusion in this overview.

AUTHORS' CONCLUSIONS

This overview provides the most up-to-date evidence on ART cycles from systematic reviews of randomised controlled trials. Fertility treatments are costly, and the stakes are high. Using the best available evidence to optimise outcomes is best practice. Evidence from this overview could be used to develop clinical practice guidelines and protocols that can be applied in daily clinical practice to improve live birth rates and reduce rates of multiple pregnancy, cycle cancellation, and ovarian hyperstimulation syndrome.

Prospective Randomized Trial Comparing Embryo Transfers of Cases with and without Catheter Rotation during Its Withdrawal

OBJECTIVE

To compare embryo transfer (ET) technique based on catheter rotation during its withdrawal in cases with unexplained infertility in a prospective, randomized trial (NCT03097042).

METHODS

Two hundred intracytoplasmic sperm injection (ICSI) patients undergoing ET with cleaving or blastocyst-stage fresh embryos were randomized into 2 groups: cases with (n = 100), and without (n = 100) catheter rotation during its withdrawal. Groups were matched for age and some clinical parameters. A soft catheter was used to transfer a single embryo with catheter rotation during its withdrawal in the study group and without rotation in the control. The use of a stiff catheter or tenaculum was not needed in any case. Groups were compared in terms of cycle characteristics and clinical pregnancy rates.

RESULTS

Pregnancy rate was significantly higher in the study group (41 vs. 26%, p = 0.04). Clinical pregnancy rate was also significantly higher in the study group (39 vs. 25%, OR 1.9 [1.1-3.5], p = 0.05). On the other hand, the ongoing pregnancy rate was similar between the 2 groups (33 vs. 23%, p = 0.2).

CONCLUSION

Catheter rotation during its withdrawal may be associated with increased pregnancy and clinical pregnancy rates; however, the difference in ongoing pregnancy rates did not reach statistical significance.

Evaluation of the cervix tissue homogeneity by ultrasound elastography in infertile women for the prediction of embryo transfer ease: a diagnostic accuracy study

BACKGROUND

Ultrasound elastography is a non-invasive medical imaging technique able to quantitatively characterize the stiffness of a given tissue. It has been shown to predict the risk for cervical insufficiency and preterm delivery, and to allow differentiation of malignancy from normal tissue. The present study sought to evaluate whether cervical tissue dishomogeneity, as assessed by cervical ultrasound elastography, may predict the embryo transfer (ET) ease in infertile women undergoing IVF/ICSI.

METHODS

We evaluated 154 infertile patients with no history of previous ET or intrauterine insemination. Cervical stiffness was evaluated in six regions of interest (ROI), compared two by two to obtain strain ratio (SR) values. Since a SR value of 1 was suggestive of tissue homogeneity, we computed 1-SR/SR-1 values to obtain a measure of the degree of cervical tissue dishomogeneity that we named "dishomogeneity index" (DI). Ultrasound-guided ET was performed by an expert operator blinded to the results of cervical elastography. The prediction ability of elastography on ET ease was evaluated by binary logistic regression, and the predictive accuracy of the independent variables was quantified with area under the curve (AUC) estimates derived from receiver operating characteristic (ROC) curve.

RESULTS

ET resulted to be easy in 99 out of 154 patients (64,2%), difficult in 54 patients (35%), and impossible in one. DI values in cervical medial lips region correctly classified 86.9% of patients, according to binary logistic regression, with a sensitivity of 81.4% and a specificity of 89,9%, positive likelihood ratio (LR) 8.07 and negative LR of 0.21. A DI cut-off value of 0.29 predicted a difficulty of ET with a sensitivity of 88,9% and a specificity of 85%.

CONCLUSIONS

Cervical ultrasound elastography, by allowing the identification of cervical tissue dishomogeneity, may be of help in predicting the ET ease in infertile women candidates to IVF/ICSI.

Interventions for the prevention of OHSS in ART cycles: an overview of Cochrane reviews

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) in assisted reproductive technology (ART) cycles is a treatment-induced disease that has an estimated prevalence of 20% to 33% in its mild form and 3% to 8% in its moderate or severe form. These numbers might even be higher for high-risk women such as those with polycystic ovaries or a high oocyte yield from ovum pickup.

OBJECTIVES

The objective of this overview is to identify and summarise all evidence from Cochrane systematic reviews on interventions for prevention or treatment of moderate, severe and overall OHSS in couples with subfertility who are undergoing ART cycles.

METHODS

Published Cochrane systematic reviews reporting on moderate, severe or overall OHSS as an outcome in ART cycles were eligible for inclusion in this overview. We also identified Cochrane submitted protocols and title registrations for future inclusion in the overview. The evidence is current to 12 December 2016. We identified reviews, protocols and titles by searching the Cochrane Gynaecology and Fertility Group Database of Systematic Reviews and Archie (the Cochrane information management system) in July 2016 on the effectiveness of interventions for outcomes of moderate, severe and overall OHSS. We undertook in duplicate selection of systematic reviews, data extraction and quality assessment. We used the AMSTAR (Assessing the Methodological Quality of Systematic Reviews) tool to assess the quality of included reviews, and we used GRADE methods to assess the quality of the evidence for each outcome. We summarised the characteristics of included reviews in the text and in additional tables.

MAIN RESULTS

We included a total of 27 reviews in this overview. The reviews were generally of high quality according to AMSTAR ratings, and included studies provided evidence that ranged from very low to high in quality. Ten reviews had not been updated in the past three years. Seven reviews described interventions that provided a beneficial effect in reducing OHSS rates, and we categorised one additional review as 'promising'. Of the effective interventions, all except one had no detrimental effect on pregnancy outcomes. Evidence of at least moderate quality indicates that clinicians should consider the following interventions in ART cycles to reduce OHSS rates.• Metformin treatment before and during an ART cycle for women with PCOS (moderate-quality evidence).• Gonadotrophin-releasing hormone (GnRH) antagonist protocol in ART cycles (moderate-quality evidence).• GnRH agonist (GnRHa) trigger in donor oocyte or 'freeze-all' programmes (moderate-quality evidence). Evidence of low or very low quality suggests that clinicians should consider the following interventions in ART cycles to reduce OHSS rates.• Clomiphene citrate for controlled ovarian stimulation in ART cycles (low-quality evidence).• Cabergoline around the time of human chorionic gonadotrophin (hCG) administration or oocyte pickup in ART cycles (low-quality evidence).• Intravenous fluids (plasma expanders) around the time of hCG administration or oocyte pickup in ART cycles (very low-quality evidence).• Progesterone for luteal phase support in ART cycles (low-quality evidence).• Coasting (withholding gonadotrophins) - a promising intervention that needs to be researched further for reduction of OHSS.On the basis of this overview, we must conclude that evidence is currently insufficient to support the widespread practice of embryo cryopreservation.

AUTHORS' CONCLUSIONS

Currently, 27 reviews in the Cochrane Library were conducted to report on or to try to report on OHSS in ART cycles. We identified four review protocols but no new registered titles that can potentially be included in this overview in the future. This overview provides the most up-to-date evidence on prevention of OHSS in ART cycles from all currently published Cochrane reviews on ART. Clinicians can use the evidence summarised in this overview to choose the best treatment regimen for individual patients - a regimen that not only reduces the chance of developing OHSS but does not compromise other outcomes such as pregnancy or live birth rate. Review results, however, are limited by the lack of recent primary studies or updated reviews. Furthermore, this overview can be used by policymakers in developing local and regional protocols or guidelines and can reveal knowledge gaps for future research.

Intrauterine administration of human chorionic gonadotropin (hCG) for subfertile women undergoing assisted reproduction

BACKGROUND

Subfertility affects 15% of couples and represents the inability to conceive naturally following 12 months of regular unprotected sexual intercourse. Assisted reproduction refers to procedures involving the in vitro handling of both human gametes and represents a key option for many subfertile couples. Most women undergoing assisted reproduction treatment will reach the stage of embryo transfer (ET) but the proportion of embryos that successfully implant following ET has remained small since the mid-1990s. Human chorionic gonadotropin (hCG) is a hormone synthesised and released by the syncytiotrophoblast and has a fundamental role in embryo implantation and the early stages of pregnancy. Intrauterine administration of synthetic or natural hCG via an ET catheter during a mock procedure around the time of ET is a novel approach that has recently been suggested to improve the outcomes of assisted reproduction.

OBJECTIVES

To investigate whether the intrauterine administration of hCG around the time of ET improves the clinical outcomes in subfertile women undergoing assisted reproduction.

SEARCH METHODS

We performed a comprehensive literature search of the Cochrane Gynaecology and Fertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, PsycINFO, registers of ongoing trials andreference lists of all included studies and relevant reviews (from inception to 10 November 2015), in consultation with the Cochrane Gynaecology and Fertility Group Trials Search Co-ordinator.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) evaluating intrauterine administration of hCG around the time of ET in this review irrespective of language and country of origin.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies, assessed risk of bias, extracted data from studies and attempted to contact the authors where data were missing. We performed statistical analysis using Review Manager 5 in accordance with the Cochrane Handbook for Systematic Reviews of Interventions. We assessed evidence quality using GRADE methods.

MAIN RESULTS

Twelve RCTs investigated the effect of intrauterine administration of hCG for 4038 subfertile women undergoing assisted reproduction. The intra-cavity hCG (IC-hCG) was administered in variable doses at different timings before the ET. The source of hCG was from the urine of pregnant women or from cell cultures using recombinant DNA technology.Most of the studies (9/12) were at high risk of bias in at least one of the seven domains assessed. Common problems were unclear reporting of study methods and lack of blinding. The main limitations in the overall quality of the evidence were high risk of bias and serious imprecision.For the analyses of live birth and clinical pregnancy, there was considerable heterogeneity (I(2) greater than 75%) and we did not undertake a meta-analysis. Exploration for the sources of heterogeneity identified two key pre-specified variables as important determinants: stage of ET (cleavage versus blastocyst stage) and dose of IC-hCG (less than 500 international units (IU) versus 500 IU or greater). We then performed meta-analysis for these analyses within the subgroups defined by stage of embryo and dose of IC-hCG.There was an increase in live birth rate in the subgroup of women having cleavage-stage ETs with an IC-hCG dose of 500 IU or greater compared to women having cleavage-stage ETs with no IC-hCG (risk ratio (RR) 1.57, 95% confidence interval (CI) 1.32 to 1.87, three RCTs, n = 914, I(2) = 0%, moderate quality evidence). In a clinic with a live birth rate of 25% per cycle then the use of IC-hCG -500 IU or greater would be associated with a live birth rate that varies from 33% to 46%. We did not observe a significant effect on live birth in any of the other subgroups.The was an increase in clinical pregnancy rate in the subgroup of women having cleavage-stage ETs with an IC-hCG dose of 500 IU or greater compared to women having cleavage-stage ETs with no IC-hCG (RR 1.41, 95% CI 1.25 to 1.58, seven RCTs, n = 1414, I(2) = 0%, moderate quality evidence). We did not observe a significant effect on clinical pregnancy in either of the other subgroups.There was no evidence that miscarriage was influenced by intrauterine hCG administration (RR 1.09, 95% CI 0.83 to 1.43, seven RCTs, n = 3395, I(2) = 0%, very low quality evidence).Other complications reported in the included studies were ectopic pregnancy (three RCTs, n = 915, three events overall), heterotopic pregnancy (one RCT, n = 495, one event), intrauterine death (two RCTs, n = 978, 21 events) and triplets (one RCT, n = 48, three events). There was no evidence of a difference between the groups, but there were too few events to allow any conclusions to be drawn and the evidence was very low quality.

AUTHORS' CONCLUSIONS

The pregnancy outcome for cleavage-stage ETs using an IC-hCG dose of 500 IU or greater is promising. However, given the small size and the variable quality of the trials and the fact that the positive finding was from a subgroup analysis, the current evidence for IC-hCG treatment does not support its use in assisted reproduction cycles. A definitive large clinical trial with live birth as the primary outcome is recommended. There was no evidence that miscarriage was influenced by intrauterine hCG administration, irrespective of embryo stage at transfer or dose of IC-hCG. There were too few events to allow any conclusions to be drawn with regard to other complications.

Assisted reproductive technology: an overview of Cochrane Reviews

BACKGROUND

As many as one in six couples will encounter problems with fertility, defined as failure to achieve a clinical pregnancy after regular intercourse for 12 months. Increasingly, couples are turning to assisted reproductive technology (ART) for help with conceiving and ultimately giving birth to a healthy live baby of their own. Fertility treatments are complex, and each ART cycle consists of several steps. If one of the steps is incorrectly applied, the stakes are high as conception may not occur. With this in mind, it is important that each step of the ART cycle is supported by good evidence from well-designed studies.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on procedures and treatment options available to couples with subfertility undergoing assisted reproductive technology (ART).

METHODS

Published Cochrane systematic reviews of couples undergoing ART (in vitro fertilisation or intracytoplasmic sperm injection) were eligible for inclusion in the overview. We also identified Cochrane reviews in preparation, for future inclusion.The outcomes of the overview were live birth (primary outcome), clinical pregnancy, multiple pregnancy, miscarriage and ovarian hyperstimulation syndrome (secondary outcomes). Studies of intrauterine insemination and ovulation induction were excluded.Selection of systematic reviews, data extraction and quality assessment were undertaken in duplicate. Review quality was assessed by using the AMSTAR tool. Reviews were organised by their relevance to specific stages in the ART cycle. Their findings were summarised in the text and data for each outcome were reported in 'Additional tables'.

MAIN RESULTS

Fifty-nine systematic reviews published in The Cochrane Library up to July 2015 were included. All were high quality. Thirty-two reviews identified interventions that were effective (n = 19) or promising (n = 13), 14 reviews identified interventions that were either ineffective (n = 2) or possibly ineffective (n = 12), and 13 reviews were unable to draw conclusions due to lack of evidence.An additional 11 protocols and five titles were identified for future inclusion in this overview.

AUTHORS' CONCLUSIONS

This overview provides the most up to date evidence on ART cycles from systematic reviews of randomised controlled trials. Fertility treatments are costly and the stakes are high. Using the best available evidence to optimise outcomes is best practice. The evidence from this overview could be used to develop clinical practice guidelines and protocols for use in daily clinical practice, in order to improve live birth rates and reduce rates of multiple pregnancy, cycle cancellation and ovarian hyperstimulation syndrome.

Antibiotics prior to embryo transfer in ART

BACKGROUND

Embryo transfer (ET) involves the placement of one or more embryos into the uterine cavity, usually by passing a catheter through the cervical os. ET is the final step in an assisted reproductive technology (ART) cycle, where a woman has undergone controlled ovarian stimulation, egg retrieval and in vitro fertilisation of her eggs. Despite the transfer of high quality embryos, many ETs do not result in a pregnancy. There are many factors which may affect the success of ET, including the presence of upper genital tract microbial colonisation. The administration of antibiotics prior to ET has been suggested as an intervention to reduce levels of microbial colonisation and hence improve pregnancy rates.

OBJECTIVES

To evaluate the effectiveness and safety of antibiotic administration prior to ET during ART cycles.

SEARCH METHODS

We searched the Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane Library, MEDLINE, Ovid MEDLINE® In-Process & Other Non-Indexed Citations, Ovid MEDLINE® Daily and Ovid MEDLINE® (from inception to February 2011), Ovid EMBASE (January 2010 to February 2011), Ovid PsycINFO, CINAHL, LILACS, trial registers for ongoing and registered trials, citation indexes, ClinicalStudyResults, PubMed, OpenSIGLE database and for for herbal and complimentary therapy protocols and reviews.

SELECTION CRITERIA

Only randomised controlled trials were included.

DATA COLLECTION AND ANALYSIS

The titles and abstracts of articles identified by the search were screened by one review author for eligibility. Two review authors then independently examined the full text articles for suitability for inclusion in the review. Data were extracted independently by two review authors.

MAIN RESULTS

We identified four potential studies, of which three were excluded.The included trial reported clinical pregnancy rates but not live births. There was no evidence of a difference in clinical pregnancy rate between those receiving an amoxycillin and clavulanic acid antibiotic combination (64/178: 36%) and those not (61/172: 35.5%) (OR1.02, 95% CI 0.66 to 1.58). Genital tract colonisation was significantly reduced in women receiving this antibiotic regimen (OR 0.59, 95% CI 0.37 to 0.95).

AUTHORS' CONCLUSIONS

This review suggests that the administration of amoxycillin and clavulanic acid prior to embryo transfer reduced upper genital tract microbial contamination but did not alter clinical pregnancy rates. The effect of this intervention on live birth is unknown. There are no data from randomised controlled trials to support or refute other antibiotic regimens in this setting.Future research is warranted to assess the efficacy of alternative antibiotic regimens. Researchers should assess live birth as the primary outcome and address quantitative microbial colonization as a secondary outcome.