Pregnancy rates after embryo transfer depend on the provider at embryo transfer

What is the best site for embryo deposition? A systematic review and meta-analysis using direct and adjusted indirect comparisons

The site of embryo replacement has been postulated as being important to the success of IVF/ICSI. In order to determine the best site for embryo deposition during embryo transfer, a meta-analysis of randomized trials comparing different uterine deposition sites was undertaken. Electronic (e.g. PubMed, EMBASE, Cochrane Library, LILACS) and hand searches were performed to locate trials. Outcomes measures were the live-birth (LBR), ongoing pregnancy (OPR), and clinical pregnancy rates (CPR). Assessments of the endometrial cavity length (ECL) and the distance from the fundus to the tip of the catheter (DTC) were utilized. Six studies were identified, of which three were excluded. Meta-analysis was conducted with the Mantel-Haenszel method, utilizing the fixed-effects model. The LBR and OPR showed an increasing trend when transfers were performed to the lower half of the uterine cavity. For the DTC, all rates were significantly higher for the approximately 20 mm versus approximately 10 mm distance from the uterine fundus, supporting the results of the ECL analysis. The results of this systematic review show that there is limited evidence of the superiority of lower cavity transfers (e.g. approximately 20 mm) compared with the traditional high cavity (e.g. approximately 10 mm) transfers. More well-designed and powered randomized trials are needed to confirm this conclusion.

Examination of bacterial contamination at the time of embryo transfer, and its impact on the IVF/pregnancy outcome

PURPOSE

This study was designed to examine the effect of bacterial contamination on in vitro fertilization treatment outcomes.

METHOD

In a prospective clinical trial, 152 patients aged 23-38 years, mean 33.3 +/- 4.6, undergoing IVF treatment were selected for this study. During embryo transfer, separate samples were collected for microbial examination from the following sites: the fundus of the vagina, the cervix, the embryo culture medium prior and post-embryo transfer, the tip of the catheter, and the external sheet. All the samples were separately cultured to identify any bacteria or yeast present.

RESULTS

Pregnancy rates in patients testing positive for Entrobacteriaceae (22.2% versus 51%) and Staphylococcus species (17.6% versus 44%) were significantly lower than those in the negative culture group (p < 0.001). The pregnancy rates do not seem to be affected by the other isolated microorganisms.

CONCLUSION

This study shows that the presence of vaginal-cervical microbial contamination at the time of embryo transfer is associated with significantly decreased pregnancy rates.

Uterine Position Change Between Mock and Real Embryo Transfers

OBJECTIVE

This study was designed to assess the change in uterine position between mock and real embryo transfers.

MATERIALS AND METHODS

A total of 386 embryo transfer cycles were reviewed, and the uterine position was recorded at the time of mock embryo transfer and then again at the time of real embryo transfer.

RESULTS

Of 254 patients with an anteverted uterus at mock transfer, only 3 (1.2%) were found to have a retroverted uterus at actual embryo transfer. Of 132 patients with a retroverted uterus at mock transfer, 24 (18%) had an anteverted uterus at actual embryo transfer (p < 0.0001).

CONCLUSION

Routine ultrasound-guided embryo transfer is suggested when a retroverted uterus is found at mock embryo transfer, as there is a significant chance that the uterine position will change.

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.

The impact of the depth of embryo replacement on IVF outcome

PURPOSE

To evaluate the effect of the depth of embryo transfer replacement on clinical pregnancy rate.

METHODS

Data from a total of 104 consecutive embryo transfers performed on 104 women aged 26-37 years were prospectively collected for this study. All patients underwent a standard down regulation protocol for ovarian stimulation. Oocytes retrieval were performed at 36 h after hCG administration. Embryo transfer took place at 48 h after insemination. The patients were matched in two groups according to the distance between the tip of the catheter and the uterine fundus at transfer (group A > 10 < 15 mm and group B < or = 10 mm). The same method of loading embryos into the embryo transfer catheter was used.

RESULTS

Clinical pregnancy rates varied significantly (p < or = 0.05) between the two groups: 27.7% in group A and 14% in group B. The number and quality of embryos transferred did not differ between the groups.

CONCLUSIONS

The results suggest that the depth of embryo replacement may be an important variable in embryo transfer technique.

Ultrasound-guided embryo transfer does not offer any benefit in clinical outcome: a randomized controlled trial

BACKGROUND

Ultrasound-guided embryo transfer (ET) is widely suggested as a standard clinical practice that improves overall embryo implantation and pregnancy rates. Various studies of this issue suffer from methodological pitfalls, so that a randomized controlled trial, which overcomes these problems, might be valuable.

METHODS

Three hundred women aged <40, who underwent fresh ET, were included in this randomized, double-blind controlled trial. The K-J-SPPE echo tip soft catheter was used for the ultrasound-guided ET and the traditional K-Soft catheter for ETs not using ultrasound. One experienced operator performed all ETs. The primary study outcome was overall pregnancy rate (defined as the number of positive hCG results per transfer).

RESULTS

No significant differences between groups were found regarding baseline patient and embryological characteristics, except for male factor and unexplained infertility (higher in the blind and ultrasound-guided ET group, respectively, P < 0.05). Overall pregnancy rates were 53.3 and 51.3% in the ultrasound-guided and blind ET group, respectively. Two ectopic pregnancies were reported in each group. Difficulty in cervical negotiation did not differ between the two groups.

CONCLUSIONS

In patients undergoing ET by an experienced operator, ultrasound guidance did not provide any benefit in terms of overall clinical pregnancy and embryo implantation rates.

Comparison of pregnancy rates for two embryo-transfer catheters

OBJECTIVE

To compare two flexible catheters and determine whether pregnancy rates (PRs) differed.

DESIGN

Prospective, randomized pilot study.

SETTING

Tertiary-care infertility practice.

PATIENT(S)

The subjects for this study were 100 women undergoing assisted reproductive technology (ART) cycles between September 2003 and October 2005.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE

Clinical PR for Edwards-Wallace (Cooper Surgical, Shelton, CT) and Cook World (Cook Urological, Spencer, IN) embryo-transfer (ET) catheters.

RESULT(S)

The outcomes of pregnancy between the Edwards-Wallace and Cook World ET catheters were not significantly different. Use of the flare stimulation protocol resulted in a significantly lower PR compared to long luteal and antagonist protocols. No other variable affected PR.

CONCLUSION(S)

A 5% difference in PR was demonstrated between ET catheters; however, this study does not have the power to detect a significant difference in clinical PR between the two catheter groups. The pilot study demonstrates good design due to the lack of significant differences between the variables when stratifed by cather as well as pregnancy status. In a larger study, the flare protocol should be excluded.

Prolonged duration of transfer does not affect outcome in cycles with good embryo quality

The objective of investigating the impact of the time that embryos remain in the catheter on the outcome of cycles was assessed by measuring the period between loading the catheter and discharging the embryos in 300 transfer cycles. The pregnancy and implantation rates were similar in cycles with good embryo quality regardless of transfer duration.

Removal of cervical mucus prior to embryo transfer improves pregnancy rates in women undergoing assisted reproduction

The removal of cervical mucus during embryo transfer has been postulated to increase the pregnancy and implantation rates by not interfering with embryo implantation. Even so, this is a time-consuming procedure that may increase the incidence of difficult transfers by removing the naturally lubricant mucus. In addition, any cervical manipulations at the time of embryo transfer may cause unwarranted uterine contractions. In this prospective, controlled study, 286 women undergoing embryo transfer between January and May 2006 were divided into two groups according to whether the cervical mucus was scheduled to be aspirated (group A) or not (group B). The two groups were similar with regards to the demographics, cause of infertility, characteristics of ovarian stimulation and embryos transferred. Even so, the clinical pregnancy rate was significantly higher in group (A) than group (B) (OR = 2.18, 95% CI = 1.32-3.58), although there were easier transfers in group (B) than group (A) (OR = 3.00, 95% CI = 1.05-8.55). This demonstrates that even though embryo transfers were easier to perform when the cervical mucus was left in place, aspiration resulted in an increased chance of clinical pregnancy.

Is what we clearly see really so obvious? Ultrasonography and transcervical embryo transfer—a review

OBJECTIVE

To critically review the role of ultrasound-guided embryo transfer (ET) and its influence on the outcome of in vitro fertilization (IVF).

DESIGN

Medline review of published manuscripts.

RESULT(S)

Studies evaluating the role of ultrasound-assisted ET have had mixed results, and although meta-analysis of prospective trials suggests an improvement in outcome, limitations in study design may overstate the effect of ultrasonography. Other ET techniques may eliminate the advantages provided by ultrasonography, limiting its benefit to specific clinical scenarios. However, because no trial has demonstrated an adverse effect and because cases that may benefit from its use often cannot be predicted reliably, the routine application of ultrasonography can be justified.

Impact of Physician Performing Embryo Transfer on Pregnancy Rates in an Assisted Reproductive Program

PURPOSE

To evaluate the effect of the individual physician performing embryo transfer, on clinical pregnancy rates.

METHOD

Data from a total of 485 consecutive embryo transfers performed on 485 women aged 23-37 years were prospectively collected for this study. All patients underwent a standard downregulation long protocol for ovarian stimulation. Oocyte recovery was performed at 36 h after hCG administration. Embryo transfer took place at 48 h after insemination. The patients were matched in two groups that have been linked to two different ET providers (A and B). The same method of loading embryos into the embryo transfer catheter was used.

RESULTS

Clinical pregnancy rates varied significantly (p< or =0.01) between the two providers: 36.1% in group A and 20.6% in group B. The number and quality of embryos transferred did not differ between the groups.

CONCLUSION

The results suggest that the physician factor may be an important variable in embryo transfer technique.

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.

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.

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.

Factors affecting assisted reproductive technology (ART) pregnancy rates: a multivariate analysis

PURPOSE

To determine factors instrumental in achieving a clinical pregnancy in assisted reproductive technology (ART) patients.

METHODS

This study included 205 women undergoing their first ART cycle. Univariate and multivariate analyses were performed for patient demographics, in vitro production data, and factors associated with embryo transfer. Odds ratios (OR) were performed where appropriate.

RESULTS

Our analyses indicated that age (OR: 0.879), specific year in which the cycle was performed (OR: 2.959), and use of intracytoplasmic sperm injection (OR: 2.867) altered potential pregnancy rate. In addition, percent fertilization (OR: 1.028), number of embryos transferred (OR: 1.842), type of catheter used to transfer the embryos (OR: 0.377), presence of blood on the catheter (OR .414), and embryologist (OR: 2.338) also altered pregnancy rate.

CONCLUSIONS

Our data indicate patients' age, use of the Cook catheter, and presence of blood on the catheter reduce pregnancy rates. Performing ART in 1999, using ICSI, increasing fertilization rate, increasing number of embryos transferred (albeit less desirable when the chance of multiple gestation may occur), and transferring embryos via a particular embryologist, improve pregnancy rates.

Predictive factors for embryo implantation potential

In spite of recent improvements in IVF, pregnancy rates have not increased significantly and one of the major problems remains the high multiple pregnancy rate. Better criteria are therefore necessary to establish the viability of a transferable embryo. Early prognosis of the developmental fate of the oocyte would help in selecting the best embryos to transfer, but non-invasive selection at the oocyte stage (extracytoplasmic and intracytoplasmic morphology) has proved to be of little prognostic value. Recently, it has been shown that follicular vascularization appears to be predictive of oocyte developmental fate, making it a good first-step approach for selection. Observation of pronuclei patterns at the zygote stage appears to offer an additional prognostic tool, correlating well with IVF outcome. Morphological evaluation of the embryo at days 2-3 remains the most used and valid method of selection, even though it is not sufficient to select embryos with the higher implantation potential. Blastocyst culture is another possible strategy for selecting the best embryos with reduced risk of aneuploidies, though not all major chromosomal aberrations are excluded by prolonged in-vitro culture. In summary, selecting the best embryo for transfer is a decision that should be based on choices made during the different stages of assisted reproductive technologies.

Ultrasound-guided trial transfer may be beneficial in preparation for an IVF cycle

BACKGROUND

The objective of this study is to determine if ultrasound-guided trial transfer (UTT) in the office in preparation for an IVF cycle can be utilized as an alternative and/or adjunct to ultrasound-guided embryo transfer (UGET).

METHODS

Patients planning to undergo an IVF cycle at an academic centre were included. Each patient underwent an UTT in the office by the same practitioner. The difference in length (DL), if any, was measured from the perceived top of the uterine cavity (catheter tip) to the actual cavity apex as visualized by ultrasound.

RESULTS

Of the 64 patients enrolled, 19 patients (29.7%) had a measurable DL, of which 14 (21.9%) had a DL exists 0.5 cm, and nine (14.1%) had a DL exists 1.0 cm. Significant differences were noted between patients when comparing DL to previous pregnancy status and the total cavity depth (sounding depth + DL) (P < 0.05).

CONCLUSION

UTT in the office setting appears to be beneficial in preparation for an IVF cycle with embryo transfer.

Womb with a view

Zygote transfer is a significant limiting factor in pregnancy rates after Assisted Reproductive Technology (ART) treatment. Adequate technique appraisal should be a high priority task for any medical facility that offers this treatment. Although many clinicians have extensive personal experience, it is difficult for trainees to understand the anatomical and mechanical process of safe and adequate placing of zygotes in the uterine cavity. Ultimately, even with ultrasound help, it is a "blind procedure". The experimental module described here allows for direct visualisation of the mechanical passage of a catheter through the cervix and final placement of the tip in relation to the intravaginal visible part of the catheter. It has worldwide practical applicability for trainees and experienced clinicians accompanying the theory and allowing adequate training and retraining of all staff performing zygote transfers.

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.

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

OBJECTIVE

Given the importance of ET technique during assisted reproductive technology cycles, we evaluated the effect of embryo afterloading subsequent to placement of the ET catheter on pregnancy rates vs. a standard direct ET.

DESIGN

Retrospective cohort analysis.

SETTING

University-based assisted reproductive technology program.

PATIENT(S)

Patients undergoing a fresh nondonor day 3 ET by a single provider over a 1-year period.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy.

RESULT(S)

One hundred twenty-seven patients met inclusion criteria, and the overall pregnancy rate was 46.5%. There was no difference between the two groups with respect to age, basal FSH, or number of embryos transferred. The ET method used was at the discretion of the provider. There was no difference between the two groups in the presence of blood on the transfer catheter. However, there were significantly more transfer catheters with mucus contamination in the direct transfer group (25.58% vs. 5.95%). The clinical pregnancy rate in the group with ET using the afterloading technique was higher than in the direct ET group (52.4% vs. 34.9%).

CONCLUSION(S)

There was a trend toward an increase in pregnancy rate when an embryo afterloading technique was used. A prospective randomized trial is needed to examine this issue.

Ultrasound-guided embryo transfer and the accuracy of trial embryo transfer

BACKGROUND

Studies have suggested that ultrasound-guided embryo transfer (UG-ET) may improve the outcome in IVF; however, several factors may account for the improvement in pregnancy rate. This study examines the use of ultrasound to determine the accuracy of trial transfer (TT) in preparation for ET.

METHODS

Sixty-seven consecutive patients prospectively underwent UG-ET over a 2 month period. Total cavity length by US was compared with the length noted by TT. A difference of > or = 1 cm was considered significant. All embryos were placed within 1-2 cm of the fundus by US.

RESULTS

Twenty patients (29.9%) had a difference of > or = 1 cm and 13 patients (19.4%) had a difference of < or = 1.5 cm. Patients with a difference of > or = 1 or > or = 1.5 cm had a significantly greater depth at transfer (P < 0.001) and uterine cavity length (P < 0.001) when compared with patients without a difference. Clinical pregnancy, implantation, delivery and overall miscarriage rates did not differ between patients with a difference of > or = 1 or > or = 1.5 cm versus no difference. There were no ectopic pregnancies.

CONCLUSIONS

Nineteen percent of patients had a discrepancy of > or = 1.5 cm and approximately 30% had a difference of > or = 1 cm from TT at UG-ET, suggesting a benefit to UG-ET. A large prospective randomized trial comparing UG-ET with blind transfer is required to assess further if UG-ET should be used in all cases of ET.

Implantation Failure in Assisted Reproduction Technology and a Critical Approach to Treatment

In this article, we review the literature and our personal experience regarding the many factors that appear to influence implantation rate. Oocyte quality, as determined by patient age and aneuploidies, probably plays a major role in RIF. However, a panoply of other factors have been brought under investigation, quite often with contradictory results and additional intriguing questions to be studied. Infections of the vagina, cervix, and endometrium, the role of mucus aspiration and washing of the cervix on transfer, the role of catheter guidance for a correct transfer and potion of embryos, the effect of mock transfer, and the role of hysteroscopy and its timing before transfer procedures are analyzed both as a review of the literature and as opinions and data from our experience. Many of these factors are interlaced and from the apparently simple issue of trauma, to infections and immune modulation of hatching and implantation, a biological continuum can easily be identified. The impact of abnormalities of the immune system and of homeostasis abnormalities is also covered in a brief overview of reported works and our experience. These latter areas probably constitute the common biological background of all other external factors that, however, the skilled must equip themselves for improving implantation success.

Middle to lower uterine segment embryo transfer improves implantation and pregnancy rates compared with fundal embryo transfer

OBJECTIVE

To assess differences in pregnancy and implantation rates as a function of the embryo placement.

DESIGN

Prospective cohort study.

SETTING

A tertiary care center.

SUBJECT(S)

All fresh, nondonor IVF cycles performed in 2001.

INTERVENTION(S)

Alteration in embryo transfer (ET) target location from the fundal region to the middle to lower uterine segment.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate (sonographic sac evidence/number of transfer cycles), implantation rate (number of sacs/number of embryos transferred), patient age, peak E(2), and fertilization rate.

RESULT(S)

A total of 393 fundal and 273 lower to middle uterine segment ETs were performed. The pregnancy (PR), implantation, and birth rates were significantly higher after a middle to lower uterine segment ET compared with fundal ET (39.6% vs. 31.2%; 21% vs. 14%; and 34.1% vs. 26.2%, respectively). Groups did not differ regarding patient age, basal FSH, peak E(2), number of intracytoplasmic sperm injection (ICSI) cycles, fertilization rate, embryo quality, or number of embryos transferred.

CONCLUSION(S)

Both PR and implantation rates are favorably affected by directing embryo placement to the lower to middle uterine segment. By some unknown mechanism, it appears that this endometrial location provides a more favorable region for embryo deposition.

The Impact of Embryo Transfer on Implantation—A Review

Embryo transfer has received little clinical attention and has been, until recently, the most inefficient step in in-vitro fertilization (IVF). In this article, the authors review the literature and their personal experience regarding the process of intrauterine transfer of embryos, which remains the object of much discussion. Factors which appear to influence implantation rates are: contamination of the catheter tip with cervical bacteria, stimulation of uterine contractions during the procedure, the type of catheter, ultrasound guidance during the transfer, and the position of the embryos in the uterine cavity. Easy and atraumatic transfer is essential for successful implantation and the embryos need to be placed in the middle of the cavity, away from the fundus. Knowing, beforehand, the position and length of the uterus can provide better results and may reduce the rate of ectopic pregnancies. Evidence from randomized studies has supported this claim. Despite the number of available studies controlling certain variables, most authors, even using the same catheter, ultrasound guidance and/or a trial transfer use different protocols or similar instruments in different ways. Standardization of the transcervical intrauterine transfer of embryos in a large randomized study is needed before definitive conclusions can be drawn. The goal of improved implantation and pregnancy rates deserve these efforts.

Impact of transabdominal ultrasound guidance on performance and outcome of transcervical uterine embryo transfer

PURPOSE

To determine the impact of transabdominal ultrasound guidance on embryo transfer during IVF therapy.

METHODS

Retrospective analysis of 823 consecutive embryo transfers. Three hundred and sixty-seven procedures performed with transabdominal ultrasound guidance were compared to 456 cases performed with the "clinical touch" method.

RESULTS

Ultrasound-guided embryo transfer yielded higher, but not statistically significant, clinical pregnancy (48% vs. 44%) and implantation rates (22% vs. 20%). The incidence of multiple pregnancies, ectopic and multiple pregnancy rates were similar. The frequency of negative factors typically associated with difficult transfers, such as requirement of use of tenaculum, and presence of blood or mucus in the catheter tip, were significantly lower in the ultrasound-guided group in comparison with the clinical touch group. Ultrasound-guided embryo transfer was associated with a significantly increased easiness of transfer performance; 95% of the transfers were rated as very easy in the ultrasound-guidance group compared to 87% in the clinical touch group. The use of a soft pass catheter was the only variable independently and significantly associated with pregnancy success (odds ratio = 2.74).

CONCLUSION(S)

Ultrasound-guidance facilitates embryo transfer and in combination with the use of a soft catheter should be implemented to optimize embryo transfer results.

The transfer point is a novel measure of embryo placement

OBJECTIVE

To study the relationship between IVF-ET pregnancy outcomes and measures of embryo placement.

DESIGN

Case-control study.

SETTING

Tertiary care center.

PATIENT(S)

Twenty-three patients who underwent two ultrasonography-guided ETs, of which one resulted in a clinical pregnancy and the other did not.

MAIN OUTCOME MEASURES

Point of embryo placement normalized to the endometrial cavity length (the transfer point), distance from the point of embryo placement to the uterine fundus, time required for ET, contact with the uterine fundus, and evidence of trauma. Videotaped ETs were quantitatively analyzed.

RESULT(S)

From February 1, 2000, to March 31, 2001, videotaped ETs from 23 pairs of pregnant and nonpregnant cycles were identified. Embryo placement was more shallow in pregnancy cycles than in nonpregnancy cycles. The groups did not differ in the absolute distance of embryo placement to the fundus, ovarian stimulation, or other features of the ET.

CONCLUSION(S)

The transfer point may serve as a better marker of embryo position than does the absolute distance to the uterine fundus.

Impact of technical difficulties, choice of catheter, and the presence of blood on the success of embryo transfer--experience from a single provider

PURPOSE

To investigate the impact of technical difficulties, choice of catheter, and the presence of blood during embryo transfer on the results of in vitro fertilization and ICSI.

METHODS

A cohort of 784 consecutive cycles in 655 in vitro fertilization and ICSI patients were studied.

RESULTS

Negotiating the cervix, using the volsellum, presence of blood on the catheter wall or on the cervix did not affect the results. Changing the catheter and blood on the catheter tip reduced the pregnancy (P < 0.05 and P < 0.05) and implantation rates (P < 0.001 and P < 0.01). The Ultrasoft catheter produced higher pregnancy (P < 0.0005) and implantation rates (P < 0.01) compared to the more rigid Frydman catheter.

CONCLUSIONS

Negotiation of the cervix, the use of a volsellum, and the presence of blood on the catheter wall or on the cervix do not affect the results. Changing the catheter and blood on the catheter tip significantly diminish the pregnancy and implantation rates. Soft catheters perform better.

The usefulness of ultrasound guidance in frozen-thawed embryo transfer: a prospective randomized clinical trial

BACKGROUND

Recent randomized controlled trials have shown that implantation and pregnancy rates were improved with ultrasound-guided embryo transfer compared with clinical touch in fresh IVF cycles associated with supraphysiological ovarian steroid levels. However, the usefulness of ultrasound guidance in frozen-thawed embryo transfer where potential hormonal influences are lacking has not been appropriately investigated.

METHODS

A total of 184 consecutive patients undergoing thawed embryo transfer cycles with hormone replacement under pituitary suppression were randomized by computer-generated randomization table to two study groups: 93 had ultrasound-guided (group 1) and 91 had clinical touch (group 2) embryo transfer.

RESULTS

There was equal distribution between the two study groups with respect to the main demographic and baseline characteristics of the patients as well as the characteristics of both prior IVF cycles from which embryos were generated and cryopreserved-thawed embryo transfer cycles. However, both pregnancy and implantation rates in group 1 (34.4 and 19.8% respectively) were significantly higher than the corresponding values (19.7 and 11.9%) in group 2.

CONCLUSIONS

Ultrasound guidance in frozen-thawed embryo transfer significantly increases pregnancy and implantation rates.

Transabdominal ultrasound-guided embryo transfer does not increase pregnancy rates in oocyte recipients

OBJECTIVE

To determine whether transabdominal ultrasound guidance during embryo transfer (ET) is a useful tool for increasing pregnancy rates in patients undergoing oocyte donation.

DESIGN

Prospective, randomized, controlled trial.

SETTING

In vitro fertilization academic center.

PATIENT(S)

Three hundred seventy-four infertile patients undergoing oocyte donation.

INTERVENTION(S)

Transabdominal ultrasound-guided ET.

MAIN OUTCOME MEASURE(S)

We measured the pregnancy rate and implantation rate after transabdominal ultrasound-guided ET versus the rates in a control group who did not receive transabdominal ultrasound-guided ET.

RESULT(S)

Clear visualization at ultrasound during ET was achieved in 90.8% of the patients who had ultrasound-guided ET. A similar number of easy transfers were performed in both the ultrasound-guided and the control groups (84.5% vs. 86.6%). The pregnancy rate was comparable between the groups (59.9% ultrasound vs. 55.1% control), as was the implantation rate (30.6% ultrasound vs. 26.3% control). No differences were found in the miscarriage rate (10.7% ultrasound vs. 9.1% control) or in the multiple pregnancy rate (21.4% ultrasound vs. 22.5% control). Although all ectopic pregnancies occurred in the group that did not receive ultrasound guidance, the differences were not statistically significant (0 vs. 2.7%).

CONCLUSION(S)

We could not show any benefit in terms of pregnancy rate in oocyte recipients for whom ET was performed under direct transabdominal ultrasound visualization of the endometrial cavity. There was a lower ectopic pregnancy rate when ultrasound guidance was used, but this rate was not statistically significant in comparison with the pregnancy rate without ultrasound guidance.

Assisted reproductive technologies: toward improving implantation rates and reducing high-order multiple gestations

Despite striking progress in reproductive medicine over the past quarter century, the number of high-order multiple gestations are unacceptably high, largely as a result of the drive to maintain pregnancy rates in a competitive range. Morphologic criteria are currently used to define the reproductive competence of individual embryos but are imperfect predictors of implantation potential. Current and potential strategies to improve the selection of embryos are described. By the use of several of these approaches, it is hoped that the overall number of embryos that are transferred will be reduced, thereby also reducing the multiple gestation rate.

Pregnancy following a difficult transfer: a case report

Traumatic embryo transfers impact negatively on pregnancy rates. This study reports a clinical pregnancy obtained by transferring a blastocyst developed from a 72-h embryo, which had been retained on the catheter in a difficult transfer. A total of five oocytes was obtained from the 32-year-old patient in her first IVF treatment. Only one zygote and cleavage embryo resulted. A traumatic and bloody transfer was performed on day 3. The unique embryo was retained on the catheter. The embryo was left in culture medium until the blastocyst stage was achieved. A second transfer was performed and a successful pregnancy was achieved after transferring this blastocyst. A healthy baby was born. The results of the present report suggest that in cases of difficult transfers, waiting for the blastocyst stage might allow a second, non-traumatic transfer to be performed without embryos and cervix under the effects of stress.

The impact of the embryo transfer catheter on the pregnancy rate in IVF

BACKGROUND

The aim was to assess whether the type of embryo transfer set used for embryo transfer affects the ongoing pregnancy rate in IVF.

METHODS

The TDT set was compared with the K-soft 5000 in a large, prospective, randomized study. Patients were randomized moments before transfer by drawing a consecutively numbered, sealed, opaque envelope indicating the catheter to be used.

RESULTS

2059 embryo transfers in 1296 patients were analysed. The ongoing pregnancy rate was significantly higher in the K-soft group. If the first transfer of a patient (n = 1296) within this study period was analysed, the ongoing pregnancy rates were 27.1 versus 20.5% (P = 0.006). If the analysis is limited to patients that underwent their very first transfer ever (n = 607), the ongoing pregnancy rates were 30.3 versus 20.0% (P = 0.003) in favour of the K-soft.

CONCLUSION

We conclude from these data that the type of embryo transfer set used for embryo transfer does affect the ongoing pregnancy rate and that the impact of the variable transfer catheter on the ongoing pregnancy rate increases when the a priori chance of pregnancy increases.

Does catheter type effect pregnancy rate in intrauterine insemination cycles?

PURPOSE

To determine if a soft insemination catheter increases pregnancy rates.

METHODS

Seven hundred forty-seven consecutive intrauterine insemination (IUI) cycles in 364 women in a reproductive endocrinology office between October 1998 and March 2000. Patients with even birth years were inseminated with the Tomcat catheter, and those with odd birth year with the Wallace IUI catheter. Clinical pregnancy rates were compared.

RESULTS

The Wallace catheter group included 180 women for 372 cycles and an overall pregnancy rate of 16.4%. The Tomcat catheter group included 184 women for 375 cycles and an overall pregnancy rate of 18.1%. This difference is not statistically significant (P = 0.61). Potential confounders were accounted for.

CONCLUSIONS

When comparing the softer Wallace catheter to the less pliable Tomcat catheter during IUI cycles, there was no significant difference in pregnancy rate when using a standard gentle technique that includes not touching the top of the fundus with the catheter.

Clinical practice of embryo transfer

In this review, several embryo transfer methods are considered, together with factors involved in achieving an effective transfer. The approach most used is transcervical intrauterine transfer. This is described in detail, together with the many variables influencing success, e.g. technical ability and training of personnel, catheter choice, value of a previous 'dummy transfer' and the need to minimize trauma during transfer and so prevent damage to the uterine lining, bleeding and uterine contractions. These factors can each negatively impact on pregnancy rates. Emphasis is put on quality, developmental stage and number of embryos to be transferred to limit multiple pregnancies and their unwanted side-effects. Culture to blastocyst stages and single embryo transfer when optimal quality embryos are available are discussed as means of avoiding multiple pregnancies. Reference is made to embryo cryopreservation and fertility following frozen embryo transfer. Other techniques, such as ultrasound-controlled transcervical intrauterine transfer, and ultrasound-controlled transmyometrial transfer, are reviewed. More invasive procedures, generically grouped as surgical embryo transfer, including gamete intra-Fallopian transfer (GIFT), zygote intra-Fallopian transfer (ZIFT), pronuclear stage transfer and embryo intra-Fallopian transfer (EIFT), are also described. These techniques had a place in IVF when the need to apply assisted reproductive techniques exceeded the capacity of most laboratories, but not today thanks to refined laboratory technology and improved understanding of implantation. Alternative assisted reproductive technologies, such as direct intra-follicular insemination (DIFI), Fallopian spermatic perfusion (FSP), peritoneal oocyte stage and sperm transfer and intra-vaginal culture (IVC), are mentioned briefly.

Endometrial cavity fluid is associated with poor ovarian response and increased cancellation rates in ART cycles

BACKGROUND

Endometrial cavity fluid (ECF) is occasionally observed during assisted reproductive technology (ART) cycles. However, few reports have described its prevalence or significance.

METHODS AND RESULTS

We examined the relationships between ECF, clinical pregnancy rate (CPR), tubal factor infertility and ultrasound-visible (USV) hydrosalpinges. In 843 ART cycles involving 721 patients, ECF was observed during stimulation in 57 cycles and after human chorionic gonadotrophin (HCG) administration in 12 cycles, with an overall incidence of 8.2% (69/843). When ECF was observed during stimulation, the cancellation rate due to poor ovarian response was significantly higher (29.8 versus 16.9%, P <0.05) and the CPR per started cycle was significantly lower (26.3 versus 42.4%, P <0.05) than cycles without ECF. When ECF developed after HCG administration, the CPR was similar compared with that of the group for which ECF was not observed. In the 327 cycles involving tubal factor infertility patients, USV hydrosalpinges were noted in 71 cycles (71/327; 21.7%), and ECF developed in five of those cycles (5/71; 7.0%). A total of 27 cycles during which ECF developed (27/57, 47.4%) involved non-tubal factor patients.

CONCLUSIONS

ECF during stimulation was associated with increased cancellation rates and lower CPRs per started cycle, and was not associated with USV hydrosalpinges. Furthermore, ECF observed after HCG administration did not impact CPR and may represent a different clinical entity.

Embryo transfer: techniques and variables affecting success

OBJECTIVE

To review the literature on the variables affecting embryo transfer success or failure and to define technical factors associated with optimal outcome.

DESIGN

Literature review.

RESULTS

Avoidance of blood, mucus, bacterial contamination, excessive uterine contractions, and trauma to the endometrium is associated with optimal pregnancy and implantation rates after transcervical embryo transfer. A trial transfer, ultrasonographic guidance, and use of "soft" catheters appear to facilitate successful embryo transfer.

CONCLUSION

An understanding of the variables associated with embryo transfer success together with adherence to techniques shown to facilitate atraumatic embryo transfer will enhance the efficiency of IVF by maximizing embryo implantation.

Ultrasound-guided embryo transfer maximizes the IVF results on day 3 and day 4 embryo transfer but has no impact on day 5

BACKGROUND

The use of ultrasound-guided embryo transfer has been reported to affect success rates in some centres but not others. In a prospective study, we examined the influence of ultrasound guidance in embryo transfer performed on different days after oocyte retrieval.

METHODS

Two different methods of embryo transfer were evaluated in 1069 consecutive transfers. The ultrasound-guided embryo transfer was used in 433 cases, whereas 636 embryo transfers were performed with the tactile assessment ('clinical feel') method.

RESULTS

Ultrasound-guided embryo transfer yielded a higher overall pregnancy rate than the 'clinical feel' approach, 47 versus 36% (P < 0.001). This difference was statistically significant where embryos were transferred after 3 or 4 days of culture, 45.9 versus 37.1% (P = 0.001) and 42.3 versus 27% (P = 0.035) respectively but not significant (P = 0.112) on day 5 embryo transfer (56.3 versus 45.7%). Likewise, the implantation rate was significantly different between the two groups on day 3 and 4 embryo transfer, 23.3 versus 15.8% (P < 0.01) and 21.6 versus 15.7% (P < 0.05%) respectively but no statistical difference was noted on day 5 embryo transfer, 26.7 versus 23.6%.

CONCLUSION

Ultrasound assistance in embryo transfer on day 3 and 4 significantly improved pregnancy rates in IVF but had no impact on day 5.