Embryo transfer by midwife or gynecologist: a prospective randomized study

Steps forward in embryo transfer technique: a retrospective study comparing direct versus afterload catheters at different time frames

PURPOSE

To assess whether embryo transfer (ET) technique can influence the clinical pregnancy rate (CPR) and its correlation with the embryo transfer difficulty.

DESIGN

This single center retrospective cohort analysis of fresh and frozen single blastocyst transfers performed between January 2016 and December 2021 included fresh and frozen single blastocyst transfers performed during the study timeframe. Direct technique was the only one used from January 2016 to September 2017. From September 2017 to March 2019, the choice between the two techniques was given by randomization, due to a clinical trial recruitment. From April 2019, only the afterload technique was used. Preimplantation genetic testing cycles and gamete donation procedures and cycles performed with external gametes or embryos were excluded. CPR was the primary outcome, while difficult transfer rate the secondary one. Univariate and multivariate logistic regressions were performed.

RESULTS

During the period, 8,189 transfers were performed. CPR of the afterload group resulted significantly higher compared to the direct group (44.69% versus 41.65%, OR 1.13, 95% CI 1.02-1.25, p = 0.017) and the rate of difficult transfers two-thirds lower (9.06% versus 26.85%, OR 0.27, 95% CI 0.24-0.31, p < 0.001).

CONCLUSION

Our study demonstrated that CPR is significantly affected by the ET technique. In particular, with the afterload protocol, both CPR and easy transfer rates increased.

TRIAL REGISTRATION

http://clinicaltrials.gov registration number: NCT05364528, retrospectively registered on 3rd of May 2022.

Evidence and consensus on technical aspects of embryo transfer

BACKGROUND

Ultrasound-guided embryo transfer (US-GET) is a widely performed procedure, but standards for the best practice are not available.

OBJECTIVE AND RATIONALE

This document aims to provide an overview of technical aspects of US-GET after considering the published data and including the preparation for the embryo transfer (ET) procedure, the actual procedure, the post-procedure care, associated pathologies, complications and risks, quality assurance and practitioners’ performance.

SEARCH METHODS

A literature search for evidence on key aspects of the ET procedure was carried out from database inception to November 2021. Selected papers (n = 359) relevant to the topic were analysed by the authors. The following key points were considered in the papers: whether ultrasound (US) practice standards were explained, to what extent the ET technique was described and whether complications or incidents and how to prevent such events were reported. In the end, 89 papers could be used to support the recommendations in this document, which focused on transabdominal US-GET.

OUTCOMES

The relevant papers found in the literature search were included in the current document and described according to the topic in three main sections: requirements and preparations prior to ET, the ET procedure, and training and competence for ET. Recommendations are provided on preparations prior to ET, equipment and materials, ET technique, possible risks and complications, training and competence. Specific aspects of the laboratory procedures are covered, in particular the different loading techniques and their potential impact on the final outcomes. Potential future developments and research priorities regarding the ET technique are also outlined.

LIMITATIONS, REASONS FOR CAUTION

Many topics were not covered in the literature review and some recommendations were based on expert opinions and are not necessarily evidence based.

WIDER IMPLICATIONS

ET is the last procedural step in an ART treatment and is a crucial step toward achieving a pregnancy and live birth. The current paper set out to bring together the recent developments considering all aspects of ET, especially emphasizing US quality imaging. There are still many questions needing answers, and these can be subject of future research.

STUDY FUNDING/COMPETING INTEREST(S)

No funding. ADA has received royalties from CRC Press and personal honorarium from Cook, Ferring and Cooper Surgical. The other co-authors have no conflicts of interest to declare that are relevant to the content of this article.

Progesterone supplementation in natural cycles improves live birth rates after embryo transfer of frozen-thawed embryos-a randomized controlled trial

STUDY QUESTION

Does supplementation with vaginal tablets of progesterone after frozen-thawed embryo transfer in natural cycles improve the live birth rate?

SUMMARY ANSWER

Supplementation with vaginal tablets of progesterone after frozen-thawed embryo transfer in natural cycles significantly improves the number of live births.

WHAT IS KNOWN ALREADY

Progesterone supplementation during luteal phase and early pregnancy may improve the number of live births after frozen-thawed embryo transfer. However, due to the limited number of previous studies, being mainly retrospective, evidence is still limited.

STUDY DESIGN, SIZE, DURATION

This is a prospective randomized controlled trial, performed at two university clinics. In total, 500 subjects were randomized with a 1:1 allocation into two groups, during the period February 2013 to March 2018. Randomization was performed after a frozen embryo transfer in a natural cycle by use of opaque sealed envelopes. The primary outcome was live birth rate; secondary outcomes were pregnancy, biochemical pregnancy, clinical pregnancy and miscarriage rate, and if there was a possible association between the serum progesterone concentration on the day of embryo transfer and live birth rate.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women, receiving embryo transfer in natural cycles participated in the study. The embryos were frozen on Day 2, 3, 5 or 6. In total, 672 women having regular menstrual cycles were invited to participate in the study; of those, 500 agreed to participate and 488 were finally included in the study. Half of the study subjects received progesterone supplementation with progesterone vaginal tablets, 100 mg twice daily, starting from the day of embryo transfer. The other half of the subjects were not given any treatment. Blood samples for serum progesterone measurements were collected from all subjects on the day of embryo transfer.

MAIN RESULTS AND THE ROLE OF CHANCE

There were no differences in background characteristics between the study groups. In the progesterone supplemented group, 83 of 243 patients (34.2%) had a live birth, compared to 59 of 245 patients (24.1%) in the control group (odds ratio 1.635, 95% CI 1.102–2.428, P = 0.017*). The number of pregnancies was 104 of 243 (42.8%) and 83 of 245 (33.9%), respectively (odds ratio 1.465, 95% CI 1.012–2.108, P = 0.049*) and the number of clinical pregnancies was 91 of 243 (37.4%) and 70 of 245 (28.6%), respectively (odds ratio 1.497, 95% CI 1.024–2.188, P = 0.043*). There were no significant differences in biochemical pregnancy rate or miscarriage rate. There was no correlation between outcome and serum progesterone concentration.

LIMITATIONS, REASONS FOR CAUTION

The study was not blinded because placebo tablets were not available. Supplementation started on embryo transfer day, regardless of the age of the embryos, which resulted in a shorter supplementation time for Day 5/6 embryos compared to Day 2/3 embryos.

WIDER IMPLICATIONS OF THE FINDINGS

Supplementation with progesterone in natural cycles improved the number of live births after frozen-thawed embryo transfer and should therefore be considered for introduction in clinical routine.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by Uppsala University, the Uppsala-Family Planning Foundation, and Ferring Pharmaceuticals AB, Malmö, Sweden. The authors have no personal conflicting interests to declare.

TRIAL REGISTRATION NUMBER

NL4152.

TRIAL REGISTRATION DATE

5 December 2013.

DATE OF FIRST PATIENT’S ENROLMENT

18 February 2013.

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.

Clinical aspects of oocyte retrieval and embryo transfer. Tips and tricks for the novice and experts

Oocyte retrieval (ovum pick-up) and embryo transfer (ET) are essential steps in IVF and ICSI and over the years, the two procedures were developed in order to improve the clinical outcome. Many suggestions were proposed and applied before, during and after oocyte retrieval such as timing of HCG trigger, pre-operative pelvic scan, vaginal cleansing, type of anesthesia, type and gauge of aspiration needles, aspiration pressure, follicle flushing, and the need for prophylactic antibiotics. Similarly, many steps were suggested and implemented before, during and after ET including patient's position, type of anesthesia/analgesia, dummy (mock) ET, ultrasound-guidance, HCG injection in the uterine cavity, use of relaxing agents, full bladder, removal of the cervical mucus, flushing the cervix with culture medium, type of ET catheter, embryo loading techniques, site of embryo deposition, the use of adherence compounds, as well as bed rest after ET. Complications were also reported with oocyte retrieval and ET. The aim of this review is to evaluate the current practice of these two procedures in the light of available evidence.

Is There Any Effect of the Physician Performing Embryo Transfer in IVF-ICSI Treatment: A Prospective Cohort Study

OBJECTIVE

 To evaluate whether there is an effect of the physician who transfers the embryos on pregnancy rates in in vitro fertilization-intracytoplasmic sperm injection (IVF-ICSI) treatment.

METHODS

 A total of 757 participants were analyzed between 2012 and 2017. Participants were classified according to 3 physicians who transferred the embryos: ([group 1 = 164 patients]; [group 2 = 233 patients]; [group 3 = 360 patients]). Baseline parameters and IVF-ICSI outcomes were compared between the groups.

RESULTS

 No differences were determined between the groups regarding the baseline parameters (age, age subgroups [20-29, 30-39, and ≥ 40 years old)], body mass index (BMI), smoking status, infertility period, cause of infertility, baseline follicle stimulating hormone, luteinizing hormone, estradiol (E₂), thyroid stimulating hormone, prolactin levels, antral follicle count, duration of stimulation, stimulation protocol, gonadotropin dose required, maximum E₂ levels, progesterone levels, endometrial thickness on human chorionic gonadotropin (hCG) administration and transfer days (p > 0.05). The numbers of oocytes retrieved, metaphase II (MII), 2 pronucleus (2PN), , transferred embryo, fertilization rate, day of embryo transfer, the catheter effect and embryo transfer technique, and clinical pregnancy rates (CPRs) were also comparable between the groups (p > 0.05).

CONCLUSION

 Our data suggests that the physician who transfers the embryos has no impact on CPRs in patients who have undergone IVF-ICSI, but further studies with more participants are required to elucidate this situation.

Outcomes of embryo transfers performed by Reproductive Endocrinology and Infertility fellows vs. faculty: an 11-year retrospective review

OBJECTIVE

To compare the clinical pregnancy rate (CPR) and live birth rate (LBR) of embryo transfer episodes (ETEs) performed by Reproductive Endocrinology and Infertility fellows vs. those of ETEs performed by faculty physicians.

DESIGN

Retrospective cohort analysis.

SETTING

Academic reproductive endocrinology and infertility practice.

PATIENT(S)

In total, 3,073 ETEs for 1,488 unique patients were performed by fellows or faculty physicians between January 2009 and January 2020.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate and LBR.

RESULT(S)

Fifteen fellows performed 1,225 (39.9%) of 3,073 ETEs after completing 30 mock transfers. On comparing outcomes among fellowship years (FY1, FY2, and FY3), CPR (44.1% vs. 43.2% vs. 45.7%, respectively, P = .83) and LBR (39.1% vs. 38.1% vs. 38.4%, respectively, P = .97) were not significantly different. Fellowship year 1 fellows' initial 30 ETEs vs. all the remaining FY1 ETEs had a significantly higher CPR (48.1% vs. 40.5%, respectively, P = .030) and LBR (45.4% vs. 34.3%, respectively, P = .001). There were no significant differences between faculty versus fellow ETEs in terms of CPR (43.0% vs. 45.0%, respectively, P = .30) or LBR (37.3% vs. 39.8%, respectively, P = .16), even after adjusting for patient age, body mass index, primary infertility diagnosis, autologous vs. donor oocyte, fresh vs. frozen embryo, number of embryos transferred, type of transfer catheter, and year of transfer (P = .32 for CPR, P = .22 for LBR).

CONCLUSION(S)

Appropriately trained FY1 fellows had success rates maintained throughout all FYs. There were no significant differences in clinical outcomes between fellow- and faculty-performed transfers. These data demonstrated that allowing fellows to perform live embryo transfers is not detrimental to clinical outcomes.

The human factor: does the operator performing the embryo transfer significantly impact the cycle outcome?

STUDY QUESTION

Is Ongoing Pregnancy Rate (OPR) operator-dependent, and can experience improve embryo transfer efficiency?

SUMMARY ANSWER

OPR is influenced by the operators who perform the embryo transfer (ET), and experience does not assure proficiency for everyone.

WHAT IS KNOWN ALREADY

ET remains the critical step in assisted reproduction. Although many other factors such as embryo quality and uterine receptivity impact embryo implantation, the proper ET technique is clearly an operator-dependent variable and as such it should be objectively standardized.

STUDY DESIGN, SIZE, DURATION

Retrospective comparative analysis including all fresh ETs performed between January 1996 and December 2016 at the Humanitas Fertility Center after IVF—ICSI cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

IVF/ICSI fresh ETs performed by 32 operators, 19 824 cycles in all, were analyzed. All transfers consisting of freehand insertion of a preloaded soft catheter into the uterine cavity under transabdominal ultrasound guidance were considered. Two different statistical analyses were performed. First, a logistic regression model with a random intercept for the operator was used to estimate the heterogeneity of the rate of success among operators, accounting for woman age, FSH, number of oocytes retrieved, fertilization rate, year of the procedure, number and stage of transferred embryos and operator’s experience. Second, the relationship between experience and pregnancy rate was estimated separately for each operator by logistic regression, and operator-specific results were combined and compared in a random-effects meta-analysis. In both analyses, the operator’s experience at time t was measured in terms of number of embryo transfers performed before t.

MAIN RESULTS AND THE ROLE OF CHANCE

The heterogeneity among operators was highly significant (P value <0.001) and explained 44.5% of the total variability. The odds ratio of success of the worst operator in respect to the mean was equal to 0.84. For the best operator, the odds ratio of success was equal to 1.13 in respect to the mean. Based on the meta-analysis of the relationship between operator’s experience and success rate, it resulted that, on average, the operators’ performance did not improve with additional transfers.

LIMITATIONS, REASONS FOR CAUTION

At our center, operators become independent for ET’s after performing between 30 and 50 transfers under supervision. It is also possible that other relevant factors, such as embryologists on duty for the ET, have not been included in the present analysis and this may represent a potential bias. Among these, it should be mentioned that the embryologists on duty for the ET were not taken into consideration.

WIDER IMPLICATIONS OF THE FINDINGS

Continued performance analysis and the use of a digital simulator could help operators to test their expertise over time and either correct poor performance or avoid doing transfers.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

NCT03561129.

[Views of each member of an Assisted Reproductive Technologies centre on the embryo transfer procedure]

The embryo transfer (ET) is probably the key step of Assisted Reproductive Technologies (ART), end point of the collaboration of a multidisciplinary clinical team and an infertile couple. Thus, a perfect knowledge of available data regarding ET is required to optimize the results of ART. Indeed, numerous published studies demonstrate the impact of defined parameters onto the effectiveness of ET procedure. The aim of this study is to provide views of physicians dealing with ART, i.e. endocrinologist, ultrasound scan specialist, surgeon and biologist to put in perspective questions and answers about ET.

Should a patient's own IVF physician perform the embryo transfer?

PURPOSE

To compare pregnancy rates of embryo transfers performed by a patient's own IVF physician to pregnancy rates of embryo transfers performed by other physicians on the IVF team.

METHODS

Retrospective cohort study; University hospital.

RESULTS

A total of 3029 embryo transfers were included. 434 patients (14%) had an embryo transfer by their own IVF physician. There was no difference in pregnancy rates comparing patients who had embryos transferred by a different physician than their own IVF physician when all cycle attempts were analyzed [Odds ratio (OR) 1.1; Confidence interval (CI) 0.9-1.4]. There was no significant difference between the groups' population characteristics. A subset analysis of 1st cycle only embryo transfers (n=1416) also revealed no difference in pregnancy rates [OR 1.1; CI 0.8-1.5].

CONCLUSIONS

Patients can be reassured that their chances of pregnancy are the same whether their embryo transfer is performed by their own physician or another physician in the practice.

Embryo transfer: factors involved in optimizing the success

PURPOSE OF REVIEW

Embryo transfer is arguably the most critical step in assisted reproduction. The purpose of this article is to review the different aspects of the procedure in the light of recent evidence.

RECENT FINDINGS

Randomized trials have shown that significantly higher pregnancy rates are obtained when embryo transfer is performed under ultrasound guidance, the embryos are deposited in the middle part of the uterine cavity, an atraumatic technique is used and when low-dose aspirin is routinely administered following the procedure. Blood in the catheter and leaving the embryos inside it for more than 120 s diminish the pregnancy rate significantly. Air in the catheter, immediate removal of the catheter, performing two transfers in the same cycle, prolonged bed rest, sexual intercourse after embryo transfer or the use of sildenafil do not affect the results. Based on currently available evidence, Cochrane reviews have concluded that the live birth rate is not increased by delaying embryo transfer from day two to three or to the blastocyst stage, and that single embryo transfer leads to lower live birth rates than the transfer of two embryos. The value of a mock transfer a few days before the actual procedure has been challenged as the position of the uterus may change. The effect of holding the cervix with a volsellum, routinely administering antibiotics and the superiority of one catheter over the others is still to be determined.

SUMMARY

Recent studies confirm the importance of the various aspects of embryo transfer. More randomized studies are needed to further evaluate them.

Ongoing pregnancy rates in in vitro fertilization are not dependent on the physician performing the embryo transfer

OBJECTIVE

To analyze the influence of the factor of the physician performing the ET with a standardized procedure on the ongoing pregnancy rates in an IVF-ET program.

DESIGN

Prospective observational study.

SETTING

Tertiary university hospital.

PATIENT(S)

Subfertile women with an IVF indication.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Ongoing pregnancy.

RESULT(S)

Six physicians performed 977 ETs. Ongoing pregnancy rates ranged from 19.1% to 29.0%, with an average rate of 23.1%. Logistic regression analysis revealed that physician is not a statistically significant variable. Differences between the pregnancy rates achieved by the physicians are within the limits of random variation.

CONCLUSION(S)

The probability of success in IVF is not dependent on the physician, provided the transfer procedure is standardized.

Observations on reproductive health programs in the Baltic States

Public attention in Sweden has been drawn to three neighboring states that recently joined the European Union: Estonia, Latvia, and Lithuania. At this historic moment, it seems instructive to look at how the rapidly reformed health sectors of these ex-Soviet republics are responding to the vision of reproductive health articulated in Cairo 10 years ago. Reproductive health and rights have improved in these states in spite of recent reforms often acting to oppose improvement. Reforms such as the introduction of family medicine need continued adjustment, especially regarding antenatal care. One special challenge is the retention of essential mid-level providers, such as midwives, as the mode of HIV transmission becomes increasingly sexual.