Embryo afterloading: a refinement in embryo transfer technique that may increase clinical pregnancy

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.

Effects of embryo retention during embryo transfer on IVF outcomes

PROPOSE

To investigate embryo retention (ER) rate in embryo transfer (ET) cycles and its effects on reproductive outcomes in a large database.

METHODS

A matched retrospective cohort study in a tertiary academic hospital-based reproductive center. A total of 15,321 ET cycles were performed from January 2008 to December 2018. Each woman was matched with three separate control subjects of the same age (± 1 year), embryo condition, main causes of infertility, and type of protocol used for fresh or frozen ET cycles. The main outcomes were ER rate, and implantation, clinical pregnancy, ectopic pregnancy, and live birth rates.

RESULTS

The overall incidence of ER was 1.4% (213/15,321). There was no difference in the rate of ER rate in fresh ET cycles compared with frozen transfer cycles (P = 0.54). We matched 188/213 (88%) of cases in the ER group to 564 non-ER cases. There were no cases of the blood in the catheter seen in the ER group. Pregnancy outcomes were similar between the ER and the non-ER cycles: clinical pregnancy rate (31.3% vs. 36.1%, P = 0.29), implantation rate (26.2% vs. 31.3%, P = 0.2), live birth rate (20.3% vs. 24%, P = 0.53), ectopic pregnancy rate (0.5% vs. 0.4%, P = 0.18), and miscarriage rate (10.7% vs. 11.3%, P = 0.53).

CONCLUSION

Our results suggest that ER rate does not affect the reproductive outcomes including clinical pregnancy rate, implantation rate, and live birth rate. Patients and physicians should not be concerned about the retention of embryos during transfer since there is no effect on pregnancy outcome.

The effect of embryo transfer technique on pregnancy rates in in vitro fertilization-intracytoplasmic sperm injection cycles: A prospective cohort study

Objective:

To investigate whether embryo transfer affects pregnancy rates in in vitro fertilization-intracytoplasmic sperm injection (IVF-ICSI) treatment.

Materials and Methods:

A total of 2,257 patients who underwent IVF-ICSI treatment between 2012 and 2017 were included in this study. Subjects were categorized according to the embryo transfer technique that was required: group 1 (n=1,657) underwent easy transfer with a soft catheter; group 2 (n=548) received external guidance transfers; and group 3 (n=52) experienced difficult transfers with a stylet. Basal parameters, clinical and laboratory IVF-ICSI outcomes, and clinical pregnancy rates (CPR) were compared between the groups.

Results:

There were no differences between the groups in terms of age, body mass index, smoking status, duration and etiology of infertility, baseline folliclestimulating hormone, luteinizing hormone, estradiol (E₂), thyroid-stimulating hormone, prolactin levels, antral follicle count, duration of stimulation, stimulation protocol, total gonadotropin dose required, peak E₂ levels, progesterone levels, and endometrial thickness on human chorionic gonadotropin administration and transfer days (p>0.05). The numbers of oocytes retrieved, MII and 2PN, fertilization rate, day of embryo transfer, and CPRs were also comparable between the groups (p>0.05).

Conclusion:

Our data suggest that embryo transfer has no impact on pregnancy rates in patients who undergo IVF-ICSI treatment. Further studies with more participants are required to elucidate this situation.

Simulation training for embryo transfer: findings from the American Society for Reproductive Medicine Embryo Transfer Certificate Course

OBJECTIVE

To assess the value of the American Society for Reproductive Medicine Embryo Transfer Certificate Course in confidence and skill building for performing a live embryo transfer (ET).

DESIGN

Prospective cohort study.

SETTING

Two-day simulation workshops of reproductive endocrine and infertility (REI) fellows from American Board of Obstetrics and Gynecology-approved training programs, using four different uterine models (A-D).

PATIENT(S)

None.

INTERVENTION(S)

Didactic and hands-on simulation training program.

MAIN OUTCOME MEASURE(S)

Primary outcomes included ET simulation scores of all exercises analyzed at various points of the training and self-assessed confidence before and after the completion of the Embryo Transfer Certificate Course based on a 6-point Likert scale and association of both with extent of prior live ET experience and year of fellowship.

RESULT(S)

Data were collected for 78 REI fellows who completed the Embryo Transfer Certificate Course and demonstrated significant improvements in both skill and confidence. The data for a subset of 58 fellows who performed five direct transfers on both Embryo Transfer Certificate Course uterine models A and B demonstrated significant overall improvement in ET simulation scores between the first and fifth direct transfers. A separate data subset of 57 fellows who performed five afterload transfers for each exercise on all four uterine models demonstrated differences in difficulty among them. Embryo transfer simulation using the uterine A model was consistently the easiest. The ET simulation scores for fellows using the uterine B and C models showed a progressive and significant increase across the five afterload ETs. When using the uterine D model, ET simulation scores increased significantly between the first and second transfers but remained at the same level for the remaining three transfers. Except for uterus A, a significant increase in ET simulation scores between the first and last transfers was observed for fellows overall in all afterload transfers and for those fellows with <50 prior live transfers. Data for all 78 fellows demonstrate a significant gain of self-confidence for all parameters, with the highest overall increase (78%) observed for first-year fellows as well as for fellows of any year with no prior live transfer experience (109%). Fellows with the largest number of prior live ET experience started with higher confidence, which also increased significantly, although they had a lower gain in confidence compared with fellows with less experience.

CONCLUSION(S)

The American Society for Reproductive Medicine Embryo Transfer Certificate Course data analysis demonstrates the effectiveness of simulator-based ET training for REI fellows across the 3 years of training, regardless of prior experience with live ET.

Does the Time of Starting Progesterone Luteal Support Affect Embryo Transfer in Long Agonist Protocol Downregulated ICSI Cycles? A Randomized Controlled Trial

The aim of this study was to compare the effects of starting progesterone (P4) luteal support (LS) on day of egg retrieval (ER) or day of embryo transfer (ET) on the ratio of difficult ET and cycle outcome. This was a RCT ( ClinicalTrials.gov Identifier: NCT03040830) carried out at Mansoura Integrated Fertility Center (MIFC), Mansoura, Egypt, from November 2015 to January 2017. A total of 171 eligible long agonist ICSI cases were randomly allocated on day of ER into group A (86) starting LS as daily IM 100 mg P4 on day of ER and group B (85) starting P4-LS on day of ET. Difficult ET was defined as blood on ET catheter and/or sounding or dilating the cervix. Primary outcome was the overall ratio of difficult ET and ratios on day 3 and 5 ET. Secondary outcome was the ongoing pregnancy rate (OPR) and implantation rate (IR). The results are presented as % for groups A and B respectively: overall difficult ET (44.1, 24.7) (p = 0.009); day 3 difficult ET (23.2, 24.4) (p = 0.45); day 5 difficult ET (62.7, 25.6) (p = 0.001); overall OPR (38.3, 44.7) (p = 0.43); day 3 ET OPR (41.8, 33.3) (p = 0.51); day 5 ET OPR (34.8, 57.5) (p = 0.048); overall IR (20.0, 22.5) (p = 0.62); day 3 ET IR (17.8, 13.4) (p = 0.44); day 5 ET IR (22, 34.1) (p = 0.09). In conclusion, starting P4 luteal support on egg retrieval day is associated with significantly higher ratio of difficult embryo transfer and lower ongoing pregnancy rate and tendency to lower IR in day 5 ET, so starting P4-LS on day of ET is recommended.

The Influence Of Intrauterine Pressure On Embryo Retention In A Catheter After Embryo Transfer

The retention of the embryo in the transfer catheter after embryo transfer (ET) during in vitro fertilization is a very common phenomenon, encountered by even the most experienced operators, and embryos retained in the transfer catheter or its sleeve require a repeat transfer. The exact mechanism of embryo retention has not been explained. Therefore, the present study aimed to investigate the mechanism of embryo retention in the catheter during embryo transfer by using a transparent uterus model equipped with pressure sensors and a video recorder. The results indicate that pressure changes in the uterine cavity during ET can influence the distribution of the transferred fluid containing the embryo. Under certain conditions, the transferred fluid can flow backward in the catheter, which may lead to retention of the embryo in the catheter.

Vitrified blastocyst transfer cycles with the use of only vaginal progesterone replacement with Endometrin have inferior ongoing pregnancy rates: results from the planned interim analysis of a three-arm randomized controlled noninferiority trial

OBJECTIVE

To assess the noninferiority of vaginal P (Endometrin) compared with daily intramuscular P for replacement in programmed vitrified-warmed blastocyst transfer cycles and to assess the noninferiority of vaginal P in combination with intramuscular progesterone every third day compared with daily intramuscular P.

DESIGN

Three-arm randomized controlled noninferiority study. To enable early recognition of inferiority if present, an a priori interim analysis was planned and completed once ongoing pregnancy data were available for 50% of the total enrollment goal. The results of this interim analysis are presented here.

SETTING

Assisted reproduction technology practice.

PATIENT(S)

Women undergoing transfer of nonbiopsied high quality vitrified-warmed blastocyst(s) in a programmed cycle.

INTERVENTION(S)

Vitrified-warmed blastocyst transfer with mode of P replacement determined by randomization to either: (1) 50 mg daily intramuscular P only; (2) 200 mg twice daily vaginal Endometrin; or (3) 200 mg twice daily Endometrin plus 50 mg intramuscular P every 3rd day.

MAIN OUTCOME MEASURE(S)

Live birth. The primary outcome of this interim analysis was ongoing pregnancy.

RESULT(S)

A total of 645 cycles were randomly assigned to one of the three treatment arms, received at least one dose of P replacement therapy according to this assignment and underwent vitrified-warmed blastocyst transfer. These cycles were included in the intention-to-treat analysis. The study team, including the statistician, were blinded to the identity of the treatment arms, which were randomly labeled "A," "B," and "C" in the dataset. Ongoing pregnancy occurred in 50%, 47%, and 31% of cycles in arms A, B, and C respectively. Although arm C had an rate of positive hCG equivalent to the other two arms, the rate of pregnancy loss for arm C was significantly higher than for either of the two arms, resulting in a more than one-third lower rate of ongoing pregnancy. There were no statistically significant differences for any outcome tested between arms A and B. Results of a per-protocol analysis were nearly identical to those of the intention-to-treat analysis. On completion of these analyses, arm C was revealed to be the vaginal P only arm.

CONCLUSION(S)

Relative to regimens inclusive of intramuscular P, vaginal-only P replacement for vitrified-warmed blastocyst transfer results in decreased ongoing pregnancy, due to increased miscarriage, and should be avoided. Randomization to the vaginal-only arm was terminated with these findings. This trial is ongoing to assess the noninferiority of the vaginal plus every 3rd day intramuscular P arm compared with daily intramuscular P in terms of live birth.

CLINICAL TRIAL REGISTRATION NUMBER

NLM identifier NCT02254577.

Embryo transfer simulation improves pregnancy rates and decreases time to proficiency in Reproductive Endocrinology and Infertility fellow embryo transfers

OBJECTIVE

To design and evaluate an ET simulator to train Reproductive Endocrinology and Infertility (REI) fellows' techniques of ET.

DESIGN

Simulation model development and retrospective cohort analysis.

SETTING

Not applicable.

PATIENT(S)

Patients undergoing IVF.

INTERVENTION(S)

Simulation model evaluation and implementation of ET simulation training.

MAIN OUTCOME MEASURE(S)

Pregnancy rates.

RESULT(S)

The REI fellow and faculty evaluation responses (n = 19/21 [90%]) of the model demonstrated realistic characteristics, with evaluators concluding the model was suitable for training in almost all evaluated areas. A total of 12 REI fellows who performed ET were analyzed: 6 before ET trainer and 6 after ET trainer. Pregnancy rates were 31% in the initial 10 ETs per fellow before simulator vs. 46% after simulator. One of six pre-ET trainer fellows (17%) had pregnancy rates ≥40% in their first 10 ETs; whereas four of six post-ET trainer fellows had pregnancy rates ≥40% in their first 10 ETs. The average number of ETs to obtain >40% pregnancy efficiency was 27 ETs before trainer vs. 15 ETs after trainer. Pregnancy rates were similar in the two groups after 20 ETs, and collective terminal pregnancy rates were >50% after 40 ETs.

CONCLUSION(S)

Embryo transfer simulation improved REI fellow pregnancy rates in their first 10 transfers and led to a more rapid ET proficiency. These data suggest potential value in adopting ET simulation, even in programs with a robust history of live ET in fellowship training.

Does the Presence of Blood in the Catheter or the Degree of Difficulty of Embryo Transfer Affect Live Birth?

The technique used for embryo transfer (ET) can affect implantation. Prior research that evaluated the effect of postprocedural blood of the transfer catheter tip have yielded mixed results, and it is unclear whether this is actually a marker of difficulty of the transfer. Our objective was to estimate the effect of blood at the time of ET and the difficulty of ET on live birth rates (LBR). This retrospective cohort study utilized generalized estimating equations (GEEs) with nesting for repeated cycles for all analyses. Univariate modeling was performed and a final multivariate (adjusted) GEE model accounted for all significant confounders. Embryo transfers were subjectively graded (easy, medium, or hard) by a physician at the time of transfer. The presence of blood at ET was associated with more difficult ETs, retained embryos, and presence of mucous in the catheter. In the univariate analysis, ET with blood was not associated with live birth, while the degree of difficulty for ET had a negative impact on LBR. In the final multivariate GEE model, which accounts for repeated cycles from a patient, the only factors associated with an increased LBR were the degree of difficulty of the ET, female age, and blastocyst transfer. After controlling for confounding variables, the presence of blood in the transfer catheter was not associated with the likelihood of pregnancy and thus was not an independent predictor of cycle outcome. This indicates that the difficulty of the transfer itself was a strong negative predictor of pregnancy.

Reproductive outcomes of retransferring retained embryos in blastocyst transfer cycles

Objective

To determine the incidence of embryo retention (ER) in the transfer catheter following embryo transfer (ET) in blastocyst transfer and investigate whether retransferring retained embryos has an impact on reproductive outcomes in patients undergoing in vitro fertilization-ET.

Methods

We retrospectively analyzed the records of 1,131 blastocyst transfers, which comprised 223 single blastocyst transfer (SBT) and 908 double blastocyst transfer (DBT) cycles. Each SBT and DBT group was classified depending on whether ET was performed without retained embryos in the catheter during the first attempt (without-ER group) or whether any retained embryos were found following ET (ER group) for the purpose of comparing reproductive outcomes in a homogenous population.

Results

The overall incidence of finding retained embryos was 2.8% (32/1,131). There were no retained embryos in SBT cycles. In DBT cycles, implantation rates (30.0% vs. 26.6%), positive β-hCG rates (57.2% vs. 56.2%), clinical pregnancy rates (45.3% vs. 46.9%), and live birth rates (38.9% vs. 43.8%) were not significantly different between the without-ER and ER groups. There were no significant differences in the mean birth weight (g) 2,928.4±631.8 vs. 2,948.7±497.8 and the mean gestational age at birth (269.3±17.2 days vs. 264.2±25.7 days). A total of nine cases of congenital birth defects were found in this study population. Eight were observed in the without-ER group and one in the ER group.

Conclusion

Our results suggest that retransfer of retained embryos does not have any adverse impact on reproductive outcomes in blastocyst transfer cycles. Furthermore, our results support finding that SBT might be advantageous for decreasing the incidence of retained embryos in catheters.

Are intracytoplasmic sperm injection and high serum estradiol compounding risk factors for adverse obstetric outcomes in assisted reproductive technology?

OBJECTIVE

To evaluate whether intracytoplasmic sperm injection (ICSI) use and E2 on the final day of assisted reproductive technology (ART) stimulation are associated with adverse obstetric complications related to placentation.

DESIGN

Retrospective cohort study.

SETTING

Large private ART practice.

PATIENT(S)

A total of 383 women who underwent ART resulting in a singleton live birth.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Adverse placental outcomes composed of placenta accreta, placental abruption, placenta previa, intrauterine growth restriction, preeclampsia, gestational hypertension, and small for gestational age infants.

RESULT(S)

Patients with adverse placental outcomes had higher peak serum E2 levels and were three times more likely to have used ICSI. Adverse placental outcomes were associated with increasing E2 (odds ratio 1.36, 95% confidence interval 1.13-1.65) and ICSI (odds ratio 3.86, 95% confidence interval 1.61-9.27). Adverse outcomes increased when E2 was >3,000 pg/mL and continued to increase in a linear fashion until E2 was >5,000 pg/mL. The association of ICSI with adverse outcomes was independent of male factor infertility. Interaction testing suggested the adverse effect of E2 was primarily seen in ICSI cycles, but not in conventional IVF cycles. Estradiol >5,000 pg/mL was associated with adverse placental events in 36% of all ART cycles and 52% of ICSI cycles.

CONCLUSION(S)

ICSI and elevated E2 on the day of hCG trigger were associated with adverse obstetric outcomes related to placentation. The finding of a potential interaction of E2 and ICSI with adverse placental events is novel and warrants further investigation.

Impact of a prior cesarean delivery on embryo transfer: a prospective study

OBJECTIVE

To determine whether a history of prior cesarean delivery (CD) makes ET more difficult and impacts pregnancy outcomes.

DESIGN

Prospective cohort study.

SETTING

Tertiary care military facility.

PATIENT(S)

One hundred ninety-four patients with previous delivery undergoing IVF/intracytoplasmic sperm injection (ICSI)-ET.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Live birth (primary), positive hCG, clinical pregnancy, and time to perform ET.

RESULT(S)

There was no statistically significant difference between patients with a history of only vaginal deliveries versus those with a history of CD for live birth (39% vs. 32%), positive hCG (56% vs. 53%), or clinical pregnancy (49% vs. 41%). Embryo transfers took longer in the history of CD group (157 vs. 187 seconds) and were more likely to have mucus (27% vs. 45%) or blood (8% vs. 21%) on the catheter.

CONCLUSION(S)

Embryo transfers performed on patients with a prior CD took 30 seconds longer. They were also more likely to have blood or mucus on the catheter. Despite the apparently more difficult transfers, pregnancy outcomes were not different between the two groups.

Live births achieved via IVF are increased by improvements in air quality and laboratory environment

Infertility is a common disease, which causes many couples to seek treatment with assisted reproduction techniques. Many factors contribute to successful assisted reproduction technique outcomes. One important factor is laboratory environment and air quality. Our facility had the unique opportunity to compare consecutively used, but separate assisted reproduction technique laboratories, as a result of a required move. Environmental conditions were improved by strategic engineering designs. All other aspects of the IVF laboratory, including equipment, physicians, embryologists, nursing staff and protocols, were kept constant between facilities. Air quality testing showed improved air quality at the new IVF site. Embryo implantation (32.4% versus 24.3%; P < 0.01) and live birth (39.3% versus 31.8%, P < 0.05) were significantly increased in the new facility compared with the old facility. More patients met clinical criteria and underwent mandatory single embryo transfer on day 5 leading to both a reduction in multiple gestation pregnancies and increased numbers of vitrified embryos per patient with supernumerary embryos available. Improvements in IVF laboratory conditions and air quality had profound positive effects on laboratory measures and patient outcomes. This study further strengthens the importance of the laboratory environment and air quality in the success of an IVF programme.

Embryo transfer by reproductive endocrinology fellows vs attending physicians: are live birth rates comparable?

OBJECTIVE

To compare live birth rates following ultrasound-guided embryo transfer (ET) by reproductive endocrinology and infertility fellows versus attending physicians.

STUDY DESIGN

Women who underwent their first day-3, fresh, nondonor ET between Oct. 1, 2005, and April 1, 2011, at our academic center were included in this retrospective cohort study. Embryos were designated high quality if they had 8 cells, less than 10% fragmentation, and no asymmetry. ET was performed with the afterload technique under ultrasound guidance. Categorical variables were evaluated with the χ(2) test and continuous variables with the Student t test. Logistic regression was performed to assess the relationship between ET physician and live birth rate while adjusting for potential confounders.

RESULTS

Seven hundred sixty women underwent ET by an attending physician, and 104 by a fellow. Baseline characteristics were similar between the groups. The live birth rate was 31% following ET by an attending physician, compared with 34% following ET by a fellow (P = .65). Logistic regression adjusting for potential confounders demonstrated no significant association between ET physician and live birth rate.

CONCLUSION

This retrospective study demonstrated no significant difference in live birth rates following ultrasound-guided ET by fellows vs attending physicians at our institution. These data suggest that academic practices using the afterload method and ultrasound guidance can train fellows to perform ET without compromising success rates.

The simplified SART embryo scoring system is highly correlated to implantation and live birth in single blastocyst transfers

OBJECTIVE

Prior studies have validated the ability of the SART embryo scoring system to correlate with outcomes in cleavage stage embryo transfers. However, this scoring system has not been evaluated in blastocyst transfers. The objective of this study was to estimate the correlation between the simplified SART embryo scoring system and ART cycle outcomes in single blastocyst transfers.

MATERIALS AND METHODS

All fresh, autologous single blastocyst transfers cycles from a large ART center from 2010 were analyzed. Blastocysts were given a single grade of good, fair, or poor based upon SART criteria which combines the grading of the inner cell mass and trophectoderm. Multiple logistic regression assessed the predictive value of the SART grade on embryo implantation and live birth.

RESULTS

Seven hundred seventeen fresh, autologous single blastocyst transfers cycles were included in the analysis. The live birth rate was 52 % and included both elective and non-elective SBT. Chi square analysis showed higher live birth in good grade embryos as compared to fair (p=0.03) and poor (p=0.02). Univariate binary logistic regression analysis demonstrated SART embryo grading to be significantly correlated with both implantation and live birth (p<0.01). This significance persisted when patient age, BMI, and the stage of the blastocyst were controlled for with multiple logistic regression. In five patients with a poor blastocyst score, there were no live births.

CONCLUSION

These data demonstrate that the SART embryo scoring system is highly correlated to implantation and live birth in single blastocyst transfers. Patients with a good grade embryo are excellent candidates for a single blastocyst transfer.

Effect of the afterloaded external guidance embryo transfer technique on pregnancy rates in single embryo transfer cycles

OBJECTIVE

To investigate effect of the afterloaded external guidance embryo transfer technique on pregnancy rates in single embryo transfer intracytoplasmic sperm injection (ICSI) cycles.

MATERIAL AND METHODS

This retrospective study was performed at the Dr. Zekai Tahir Burak Women's Health Research and Education Hospital. Three hundred and thirteen women who underwent ICSI were included in the study. Subjects were categorized according to the embryo transfer technique; Group 1 (n: 232): easy transfer with a soft catheter, Group 2 (n: 45): after external guidance transfer, and Group 3 (n: 36): difficult transfer with a stylet. Basal parameters, clinical and laboratory IVF outcomes and pregnancy rates were studied.

RESULTS

Infertility etiology, basal follicle stimulating hormone (FSH) levels, antral follicle count, duration of stimulation, total dose of gonadotropin, peak estradiol levels, endometrial thickness, oocyte number, 2 PN, and fertilization rate were similar between the three groups (p>0.05). Despite the decreased pregnancy rate in Group 3, there were no differences in clinical pregnancy rates among the groups (p=0.204).

CONCLUSION

Embryo transfer is one of the critical steps in assisted reproduction procedures. Using the afterloaded external guidance embryo transfer technique did not improve pregnancy rates.

Improvement of pregnancy rate by modification of embryo transfer technique: a randomized clinical trial

In this randomized trial study, two groups of infertile women (n=55) aged≤40 years underwent in vitro fertilization or intracytoplasmic sperm injection treatment cycles with or without 0.2 mL of air pushed into the catheter after embryo transfer. The implantation and clinical pregnancy rates were statistically significantly higher in the study group than in the controls. This improvement on standard ET technique may advance clinical pregnancy rates.

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.

Blastocyst development rate impacts outcome in cryopreserved blastocyst transfer cycles

OBJECTIVE

To assess cycle outcome among day 5 and day 6 cryopreserved frozen-thawed blastocyst embryo transfers (FBET).

DESIGN

Retrospective cohort study.

SETTING

Military-based assisted reproduction technology (ART) center.

PATIENT(S)

One hundred seventy-two nondonor, programmed cryopreserved embryo cycles.

INTERVENTION(S)

Fully expanded blastocysts on day 5 were cryopreserved on day 5, and those achieving this state on day 6 were cryopreserved on day 6. Leuprolide acetate was given for ovulation inhibition, and endometrial supplementation was by oral and vaginal estradiol. Progesterone in oil was administered, and blastocyst transfer occurred in the morning of the sixth day of progesterone.

MAIN OUTCOME MEASURE(S)

Implantation, pregnancy, and live-birth rates.

RESULT(S)

Fresh and frozen cycle characteristics were similar between groups. Day-5 FBET had statistically significantly higher implantation rates (32.2% vs. 19.2%), which remained significant even when adjusting for covariates (odds ratio: 1.91; 95% confidence interval, 1.00, 3.67). Live-birth rates trended toward improvement after adjusting for covariates (odds ratio: 1.18; 95% confidence interval, 0.61, 2.30).

CONCLUSION(S)

Cryopreserved day-5 blastocysts have higher implantation rates and trend toward improved pregnancy outcomes compared with cryopreserved day-6 blastocysts. This suggests that embryo development rate may, in part, predict implantation and subsequent FBET outcomes, although embryos not achieving the blastocyst stage until day 6 still demonstrate acceptable outcomes.

Initial experience with a donor egg bank

OBJECTIVE

To report on the establishment of a commercial donor egg bank (CryoEggs International, LP) and to present our initial experience from the first four patients to receive eggs.

DESIGN

Case report.

SETTING

Private fertility clinic.

PATIENT(S)

The four recipient women were aged 43, 43, 40, and 33 years. All had cycle day FSH levels greater than 25 mIU/mL. All were given the option of fresh donor egg IVF but opted to use frozen donor oocytes.

INTERVENTION(S)

Purchased and quarantined frozen donor eggs were thawed and inseminated using intracytoplasmic sperm injection (ICSI). Subsequent embryos were transferred on day 3.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy as defined by presence of cardiac activity.

RESULT(S)

There was a thawed egg survival rate of 76%, a fertilization rate of 74%, a pregnancy rate (PR) of 50%, with an average of 2.75 embryos per transfer and an implantation rate of 27%.

CONCLUSION(S)

Although very preliminary, these results indicate that more widespread use of frozen donor eggs obtained from a commercial egg bank may be feasible in the future, changing the landscape of donor egg IVF.

Role of embryo transfer in fellowship training

Our objective was to survey training in ET techniques among fellows, its perceived importance, and potential barriers to ET training during fellowship. Although ET training remains an important issue for most fellows and recent graduates, 44% of respondents did not receive this training during their fellowship.

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

Cervical mucus may cover the embryo transfer catheter during passage of the cervical canal, interfering with the correct placement of the embryo(s) into the uterine cavity. The effect of removal of cervical mucus prior to embryo transfer in IVF/ intracytoplasmic sperm injection (ICSI) on live birth rate was studied. The study was set up as a single blind randomized controlled trial. Couples undergoing IVF/ICSI were randomly allocated to either removal of cervical mucus prior to embryo transfer, or a mock procedure. Randomization was done with stratification for age, cycle number and method of treatment. Primary outcome was live birth rate. A total of 317 couples were included and underwent 428 cycles, of which the outcome of 3 cycles was unknown. Baseline characteristics of both groups were comparable. Live birth occurred in 52 of 220 (24%) cycles in the treatment group and 42 of 205 (21%) cycles in the control group (risk difference 3%, 95% confidence interval-5- 11%). It is unlikely that removal of cervical mucus prior to embryo transfer has a significant effect on live birth rate. A small effect, however, cannot be excluded.

Effect of using an echogenic catheter for ultrasound-guided embryo transfer in an IVF programme: a prospective, randomized, controlled study

BACKGROUND

Recent evidence showed that ultrasound-guided embryo transfer significantly increases successful implantation compared to the clinical touch method. It has been postulated that new echodense catheters which are more readily detectable by ultrasound may refine transfer techniques even more, thus improving IVF outcome.

METHODS

A prospective, randomized, controlled trial comparing IVF outcome for women undergoing embryo transfer under ultrasound guidance by a single healthcare provider with random assignment according to a computer-generated randomization table to either standard soft Wallace catheter (standard catheter group, n=95) or the new echogenic soft Wallace catheter (echogenic catheter group, n=98).

RESULTS

The use of the echodense catheter facilitated catheter identification under ultrasound, and thus the duration of the embryo transfer procedure since the loaded catheter was handed to the physician and up to embryo discharge was significantly shorter in the echogenic catheter group as compared with the standard catheter group. There were 39 and 53 clinical pregnancies in the standard catheter (41%) and echogenic catheter (54.1%) groups, respectively. This was not statistically significant (P=0.08) according to the OR (0.6) and CIs (0.33-1.04). However, twin pregnancy rate was significantly increased (P<0.01) with the use of the new catheter which was the underlying source for obtaining significant increase in implantation rate in this group (37.1%) as compared with the standard catheter group (23.2%).

CONCLUSION

This pilot study suggests that the use of the echogenic Wallace catheter simplifies ultrasound-guided embryo transfer but not definite benefit in terms of pregnancy rates was obtained. In contrast, the use of the new catheter was associated with a significant increase in the number of twin pregnancies.