Removal of cervical mucus: effect on pregnancy rates in IVF/ICSI

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.

Interventions to optimize embryo transfer in women undergoing assisted conception: a comprehensive systematic review and meta-analyses

BACKGROUND

Several interventions and techniques are suggested to improve the outcome of embryo transfer (ET) in assisted conception. However, there remains no consensus on the optimal practice, with high variations among fertility specialists.

OBJECTIVE AND RATIONALE

We conducted a comprehensive systematic review and meta-analyses of randomized controlled trials (RCTs) aiming to identify effective interventions that could be introduced around the time of ET to improve reproductive outcomes.

SEARCH METHODS

We searched the electronic databases (MEDLINE, EMBASE and Cochrane CENTRAL) from inception until March 2021 using a multi-stage search strategy of MeSH terms and keywords, and included all RCTs that evaluated an intervention in the 24-h period before/after ET in women undergoing IVF/ICSI. Our primary outcome was clinical pregnancy rate post-ET confirmed as viable pregnancy on ultrasound scan. We assessed the risk of bias in included trials and extracted data in duplicate. We pooled data using a random-effect meta-analysis and reported using risk ratio (RR) with 95% CI. We explored publication bias and effect modifiers using subgroup analyses.

OUTCOMES

Our search yielded 3685 citations of which we included 188 RCTs (38 interventions, 59 530 participants) with a median sample size of 200 (range 26-1761). The quality of included RCTs was moderate with most showing a low risk of bias for randomization (118/188, 62.8%) and attrition (105/188, 55.8%) but there was a significant risk of publication bias (Egger's test P = 0.001). Performing ET with ultrasound guidance versus clinical touch (n = 24, RR 1.265, 95% CI 1.151-1.391, I2 = 38.53%), hyaluronic acid versus routine care (n = 9, RR 1.457, 95% CI 1.197-1.261, I2 = 46.48%) and the use of a soft versus hard catheter (n = 27, RR 1.122, 95% CI 1.028-1.224, I2 = 57.66%) led to higher clinical pregnancy rates. Other pharmacological add-ons also showed a beneficial effect including granulocyte colony-stimulating factor (G-CSF: n = 4, RR 1.774, 95% CI 1.252-2.512, I2 = 0), Atosiban (n = 7, RR 1.493, 95% CI 1.184-1.882, I2 = 68.27%) and hCG (n = 17, RR 1.232, 95% CI 1.099-1.382, I2 = 57.76%). Bed rest following ET was associated with a reduction in clinical pregnancy (n = 6, RR 0.857, 95% CI 0.741-0.991, I2 = 0.01%). Other commonly used interventions, such as non-steroidal anti-inflammatory drugs, prophylactic antibiotics, acupuncture and cervical mucus removal, did not show a significant benefit on reproductive outcomes. Our effect estimates for other important outcomes, including miscarriage and live birth, were limited by the varied reporting across included RCTs.

WIDER IMPLICATIONS

Using ultrasound guidance, soft catheters and hyaluronic acid at the time of ET appears to increase clinical pregnancy rates. The use of Atosiban, G-CSF and hCG showed a trend towards increased clinical pregnancy rate, but larger trials are required before adopting these interventions in clinical practice. Bed rest post-ET was associated with a reduction in clinical pregnancy and should not be recommended.

Does rotation during catheter withdrawal in embryo transfer increase pregnancy rates?

BACKGROUND

The aim of this study was to determine whether there is a difference in pregnancy rates between groups that we removed directly and removed by rotating the embryo transfer catheter 360°.

METHODS

The study group consisted of 552 patients who were withdrawn by 360° rotation and 797 patients who were withdrawn without catheter rotation. All patients underwent one or two fresh ETs on day 3 or 5. Groups were compared in terms of cycle characteristics and clinical pregnancy rates.

RESULTS

There were no significant differences in demographic and clinical characteristics of both groups, such as age, body mass index (BMI), duration of infertility, causes of infertility, and basal hormone levels. Clinicals pregnancy rate, in the study group, 48% (265/552) and in the control group, 50.8% (405/797) were similar in both groups. When the implantation rate and miscarriage rate were examined, both groups were found to be similar.

CONCLUSION

It was found that 360° rotation while pulling catheter during embryo transfer had no effect on pregnancy and clinical pregnancy.

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.

Cervical mucus removal prior to intrauterine insemination: a randomized trial

OBJECTIVE

To detect if removing the cervical mucus before performing intrauterine insemination (IUI) could improve pregnancy outcomes in patients with unexplained infertility.

DESIGN

Prospective randomized study.

SETTING

An Egyptian University Hospital.

POPULATION

Seven hundred and fourteen couples with unexplained infertility who underwent intrauterine insemination (IUI) with or without cervical mucus removal.

METHODS

Using computer-generated numbers, patients were randomly allocated to cervical-mucus-removal (removed from both internal and external os) or non-mucus-removal groups. Only participants were blinded as to group assignment.

MAIN OUTCOME MEASURES

The clinical pregnancy rate.

RESULTS

Of 714 IUI patients between November 2014 and March 2017, 361 were in the mucus removal group, and 353 in the non-mucus-removal group. Difficult catheterization was encountered in 17 cases out of 666 (2.6%) 12 in the cervical-mucus-removal group and five in the non-mucus-removal group). A total of 666 IUI cycles were completed while 48 were either cancelled or lost in their follow-up. The clinical pregnancy rate was significantly higher in the mucus-removal group [31.0% (n = 112)] than in the non-mucus-removal group [21.8% (n = 77); P = 0.005]. Ovarian hyperstimulation developed in 33 (4.6%) cases: 18 cervical mucus-removal and 15 non-mucus-removal. All except one were mild and managed with outpatient care.

CONCLUSIONS

Cervical mucus removal before IUI could improve pregnancy outcomes in women with unexplained infertility.

TWEETABLE ABSTRACT

Cervical mucus removal before IUI can improve pregnancy outcomes.

Absolute position versus relative position in embryo transfer: a randomized controlled trial

BACKGROUND

Meta-analysis revealed that embryo placement 20 mm from the fundal endometrial surface resulted in higher pregnancy rate, ongoing pregnancy rate, and live birth rate compared with placement 10 mm from the fundal endometrial surface. Pregnancy and implantation rates according to relative position were higher when the catheter tip was positioned close to the middle of the endometrial cavity. The aim of the current study is to evaluate differences in implantation and pregnancy rates if the site of embryo transfer is 2 cm distance from the fundal endometrium (DFE) compared to the midpoint of the endometrial cavity length (ECL).

METHODS

Patients were randomized to one of two groups: in group A (n = 98, 98 IVF-ET cycles), the embryo transfer catheter tip was positioned 2 cm DFE, while that in group B (n = 97, 97 IVF-ET cycles) was positioned at the midpoint of the ECL. We compared pregnancy outcomes of implantation rate, chemical pregnancy rate, clinical pregnancy rate, ongoing pregnancy rate, ectopic pregnancy rate, and miscarriage rate in the two groups.

RESULTS

Analysis of implantation rate (19.5 ± 27.7 vs. 21.7 ± 32.6; p = 0.6), chemical pregnancy rate (51 % vs. 50.5 %; p = 0.94), clinical pregnancy rate (35.7 % vs. 38.1 %; p = 0.73), ongoing pregnancy rate (31.6 % vs. 30.9 %; p = 0.92), ectopic pregnancy rate (8.6 % vs. 2.7 %; p = 0.35), and miscarriage rate (11.4 % vs. 16.2 %; 0.74) revealed comparable results for both groups.

CONCLUSIONS

Implantation and pregnancy rates were not influenced by the site of the ET catheter tip being 2 cm DFE compared to at the midpoint of the ECL.

ISRCTN

ISRCTN15972342.

Embryo transfer

Embryo transfer is a critical step in the overall success of in vitro fertilization (IVF). Despite its apparent simplicity, it is an integral part of the IVF cycle that can be difficult to teach and perform well. In this chapter we describe the procedure of embryo transfer and discuss various modifications that have been evaluated in an effort to improve the probability of embryo implantation including ultrasound guidance, catheter design, transfer technique, as well as enrichment of the embryo transfer media.

Techniques for preparation prior to embryo transfer

BACKGROUND

Embryo transfer (ET) is the final and most vulnerable step in in vitro fertilisation (IVF) treatment. Pregnancy rates after ET may be influenced by several factors including cervical preparation, the performance of a dummy or mock transfer, the choice of catheter, the use of ultrasound guidance, removing the mucus or blood on the catheter, and straightening of the utero-cervical angle. Recent research has focused on improving the embryo transfer technique in the hope of increasing the success rates of IVF. This review focused on preparation techniques as it is unclear whether these simple interventions will make ET an easier procedure with higher success rates and lower complication rates.

OBJECTIVES

To determine whether different preparation techniques prior to ET result in improved IVF outcomes.

SEARCH STRATEGY

The Cochrane Menstrual Disorders and Subfertility Group Specialised Register, CENTRAL (The Cochrane Library), MEDLINE, EMBASE, CINAHL, and PsycINFO were searched (November 2008). The citation lists of relevant publications, reviews, and included studies were handsearched. Experts in the field were contacted to identify any unpublished trials.

SELECTION CRITERIA

Only truly randomised controlled trials of the interventions straightening the utero-cervical angle, dummy transfer prior to ET, cervical and endometrial preparation, and embryo afterloading were included. The primary outcomes were live birth rate and pregnancy rate per woman randomised. Participants were women with any type of subfertility undergoing IVF treatment and reaching the ET stage.

DATA COLLECTION AND ANALYSIS

Two review authors critically appraised potentially eligible studies. Ten studies were included in this review and data were independently extracted by two review authors. Disagreements were resolved by discussion and involvement of a third author. Risk of bias was also independently assessed by two authors. Dichotomous outcome data were expressed as Peto odds ratios. Subgroup analysis and the investigation of heterogeneity were planned.

MAIN RESULTS

At the time of ET, there was no evidence of benefit with the following interventions: full bladder, removal of cervical mucus, flushing the endocervical canal or the endometrial cavity. We did not identify any eligible studies for dummy transfer, changing patient position, the use of a tenaculum, or embryo afterloading.

AUTHORS' CONCLUSIONS

On the basis of the evidence in this review, no specific implications for practice are made. It is recommended, in general, that more, larger studies are done on ET preparation techniques. The studies need to be of a higher quality with better explained methods, more specified inclusion and exclusion criteria, and more participants.