Ultrasound-guided soft catheter embryo transfers will improve pregnancy rates in in-vitro fertilization

Abdominal ultrasound-guided embryo transfer improves clinical pregnancy rates after in vitro fertilization: experiences from 330 clinical investigations

PURPOSE

To investigate the effect of ultrasound-guided embryo transfer on the rate of implantation and clinical pregnancy.

METHODS

A prospective randomized trial was performed to compare ultrasound-guided embryo transfer with the traditional method. A total of 330 patients were randomly divided into two groups on the day of embryo transfer. For the cases (n = 178), ultrasound-guided was used; controls (n = 152) was performed using routine methods.

RESULTS

The rate of implantation and clinical pregnancy for the cases (19.6 and 37.1%, respectively) was significantly higher than for the controls (12.6 and 25%, respectively; p < 0.05).

CONCLUSION

Ultrasound-guided embryo transfer can significantly increase the rate of implantation and clinical pregnancy, and should be recommended as a routine procedure in the process of in vitro fertilization and embryo transfer (IVF-ET).

Ultrasound guidance is not necessary during easy embryo transfers

PURPOSE

To determine whether the use of ultrasound (US) to guide embryo transfer (ET) in a population previously defined as likely to have easy transfer would change the implantation and pregnancy rates in an ICSI program.

METHODS

A total of 100 patients identified as likely to have easy transfer after mock transfer were divided into two groups: Group I, US-guided ET (N = 50) and Group II, ET without the aid of US (N = 50).

RESULTS

Implantation and pregnancy rates were similar (p = 0.51, p = 0.29) for Group I (19.6%, 42%) and Group II (16.3%, 30%), as also was the abortion rate (p = 0.55) (Group I: 1/21; Group II: 2/15).

CONCLUSION

As long as previous mock transfers are routinely performed during a cycle preceding assisted reproduction and the clinician considers transfer to be easy, ultrasound does not benefit the process of embryo transfer.

Flexible versus rigid intrauterine insemination catheters: A prospective, randomized, controlled study

OBJECTIVE

To prospectively compare pregnancy rates for couples undergoing IUI by a single healthcare provider with random assignment to either rigid (Tomcat; Kendall Sovereign, Mansfield, MA) or flexible (Soft Pass; Cook, Spencer, IN) catheters.

DESIGN

Randomized, controlled study.

SETTING

Tertiary care infertility practice.

PATIENT(S)

One hundred infertile women enrolled from a single infertility practice who met the inclusion and exclusion criteria for IUI were enrolled. Of the 100 patients, 95 underwent ovarian stimulation before IUI: 35 with clomiphene citrate alone, 60 with clomiphene citrate combined with a single dose of gonadotropins.

INTERVENTION(S)

Timed IUI was performed with either rigid (Tomcat) or flexible (Cook) insemination catheters.

MAIN OUTCOME MEASURE(S)

Pregnancy rate per cycle.

RESULT(S)

No differences were noted between groups for the following: age, length of infertility, day-3 FSH level, number of prior IUI cycles, total motile sperm count, days of abstinence, infertility diagnoses, insemination ratings, and stimulation protocols. No difference in pregnancy rates was observed between rigid and flexible catheter groups.

CONCLUSION(S)

There is no statistically significant difference between flexible and rigid catheters for IUI.

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.

ESHRE PGD Consortium ‘Best practice guidelines for clinical preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS)’

Among the many educational materials produced by the European Society of Human Reproduction and Embryology (ESHRE) are guidelines. ESHRE guidelines may be developed for many reasons but their intent is always to promote best quality practices in reproductive medicine. In an era in which preimplantation genetic diagnosis (PGD) has become a reality, we must strive to maintain its efficacy and credibility by offering the safest and most effective treatment available. The dominant motivators for the development of current comprehensive guidelines for best PGD practice were (i) the absence of guidelines and/or regulation for PGD in many countries and (ii) the observation that no consensus exists on many of the clinical and technical aspects of PGD. As a consequence, the ESHRE PGD Consortium undertook to draw up guidelines aimed at giving information, support and guidance to potential, fledgling and established PGD centres. The success of a PGD treatment cycle is the result of great attention to detail. We have strived to provide a similar level of detail in this document and hope that it will assist staff in achieving the best clinical outcome for their patients.

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.

Cannulation of a resistant internal os with the malleable outer sheath of a coaxial soft embryo transfer catheter does not affect in vitro fertilization–embryo transfer outcome

OBJECTIVE

To assess the impact of cannulation of a resistant cervical os with the outer malleable sheath of a double-lumen, soft ET catheter on IVF-ET outcomes.

DESIGN

Retrospective cohort study.

SETTING

University-based IVF center.

PATIENT(S)

One hundred forty-two patients undergoing 142 ETs.

INTERVENTION(S)

Trial ultrasound-guided ET at all transfers, leaving the malleable outer sheath in situ when the soft inner catheter could not negotiate the internal os.

MAIN OUTCOME MEASURE(S)

Implantation rate and clinical pregnancy rate.

RESULT(S)

In 102 ETs (71.8%), the soft inner sheath easily negotiated the internal os (group 1). Forty ETs (28.2%) required cannulation of resistant internal ora with the outer sheath of the trial catheter (group 2). Implantation rates (35% vs. 32% in groups 1 and 2, respectively) and clinical pregnancy rates (50% vs. 45%) were not significantly different between groups. Blood was present on the transfer catheter after ET more frequently in group 2 than in group 1 (55% vs. 15%); however, neither the implantation rate nor the clinical pregnancy rate were affected by the presence of blood.

CONCLUSION(S)

Cannulation of a resistant internal os by the malleable outer sheath and blood on the transfer catheter after ET do not have an adverse effect on implantation rate or clinical pregnancy rate.

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.

Validity of trans-rectal ultrasound-guided embryo transfer against retroflexed uterus

Background:  Embryo transfer is one of the most critical steps affecting the success of in vitro fertilization/intracytoplasmic sperm injection-embryo transfer. It has been reported that uterine contraction caused by touching the uterine fundus at the time of embryo transfer decreased the pregnancy rate. It was demonstrated that there is a significant rise in the pregnancy rate by adequate positioning of embryos. Transabdominal ultrasound-guided embryo transfer has been reported to improve the pregnancy rate compared with the clinical touch method. The improvement of the pregnancy rate under ultrasound guidance can be attributed to the accurate positioning of the embryos aided by good visualization without touching the uterine fundus. However, sometimes difficulties are encountered when visualizing the tip of the catheter in cases where the patient has a retroflexed uterus. Methods:  In the present study, we investigated the difference in the pregnancy rates and in the implantation rates between transabdominal ultrasound-guided group and trans-rectal ultrasound-guided group in retroflexed cases. Results and Conclusion:  We found that the pregnancy rate and the implantation rate were higher among the trans-rectal group compared with the transabdominal group in retroflexed cases. The difference between the two groups was statistically significant. (Reprod Med Biol 2003; 2: 159-163).

Impact des techniques de transfert sur l’implantation

Embryo transfer is an important step in the success of IVF treatment. All efforts should be made to avoid difficult embryo transfers provoking bleeding or uterine contractions. Evaluation before IVF treatment, including a trial transfer and a uterine ultrasonography, should allow one to evaluate the transfer step, anticipate problems, and thus improve treatment. An hysteroscopy can be useful for uterine cavity exploration. It is also important to remove cervical mucus before introduce the transfer catheter. It is essential to deposit embryos as gently as possible during IVF, avoiding manoeuvres that might trigger uterine contractions which could adversely affect the results of this treatment. Soft catheters perform better, and ultrasound-guidance facilitates embryo transfer. Progesterone administration starting on the day of oocyte retrieval induces a decrease in uterine contraction frequency on the day of ET (embryo transfer). Both Wallace and CDD catheters perform similarly. Trial catheterization on the day of ET could prevent most of the unanticipated procedural difficulties during the transfer.

Influence of embryo transfer depth on in vitro fertilization and embryo transfer outcomes

OBJECTIVE

To investigate the influence of transfer distance from the fundus (TDF) on clinical pregnancy rate (PR) and ectopic pregnancy rate.

DESIGN

Retrospective cohort. Between January 2000 and December 2001, 699 ultrasound (US)-guided embryo transfers were conducted. Mock transfer was performed to measure uterine cavity depth 1 month before treatment. Cavity depth was measured by abdominal US before the transfer, from the vaginal stripe to the fundus. Transfers were performed with a Wallace embryo transfer catheter (Cooper Surgical, Shelton, CT) using US and physician's judgment of cavity depth. Transfer distance from the fundus was calculated by subtracting the depth of catheter insertion from the cavity depth, as determined by US or by mock transfer. Statistical analyses were performed by building a multivariable logistic regression model to calculate odds ratios and 95% confidence intervals (CI).

SETTING

Women aged 23 to 43 years who are in a university-affiliated, community-based IVF program in Springfield, Massachusetts.

PATIENT(S)

All patients enrolled in IVF program undergoing embryo transfer.

INTERVENTION(S)

No patient received any additional procedure or intervention. All of the measurements obtained with the embryo catheter and the transvaginal ultrasound were part of the program's protocol for the embryo transfer.

MAIN OUTCOME MEASURE(S)

Odds ratio examining relationship between embryo transfer depth and PR.Clinical, implantation, and ectopic PR were 37%, 20%, and 2.1%. Cavity depth by US differed from cavity depth by mock by at least 10 mm in >30% of cases. The TDF by US was highly predictive of PR; TDF by mock was not predictive of PR. Increasing the TDF by US resulted in significantly increased PR as well as lower ectopic rates. Using regression analysis, the odds ratio for TDF by US was 1.11 (95% CI: 1.07-1.14). This suggests that for every additional millimeter embryos are deposited away from the fundus, the odds of clinical pregnancy increased by 11%.

CONCLUSION(S)

After controlling for potential confounders, the clinical PR is significantly influenced by the transfer distance from the fundus. Cavity depth by US is clinically useful to determine the depth beyond which catheter insertion should not occur.

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.

Ultrasound-guided embryo transfer: a meta-analysis of randomized controlled trials

OBJECTIVE

To conduct a meta-analysis of randomized controlled studies to evaluate abdominal ultrasound-guided embryo transfer compared to the clinical touch method.

DESIGN

Meta-analysis.

SETTING

Four studies performed in academic research centers in Barcelona, Vizcaya, Hong Kong, and Madrid.

PATIENT(S)

A total of 2,051 patients: 1,024 received ultrasound-guided embryo transfers and 1,027 received clinical touch method transfers.

INTERVENTION(S)

Fourteen studies were retrieved from the literature, but only four of them fitted our selection criteria. The meta-analysis was conducted using the RevMan software with the Peto-modified Mantel-Haenszel method and the fixed effect model.

MAIN OUTCOME MEASURE(S)

The primary outcome measures were the clinical pregnancy and ongoing pregnancy rates. The secondary outcome measures were the incidences of ectopic pregnancies, miscarriage rate, multiple pregnancies, and difficult transfers.

RESULT(S)

Compared to the clinical touch method, abdominal ultrasound-guided transfer significantly increased the clinical pregnancy rate and the ongoing pregnancy rate. There was no effect on the incidence of ectopic pregnancy, multiple pregnancy, or miscarriage rate. CONCLSUION(S): Ultrasound-guided embryo transfer increases the clinical pregnancy and ongoing pregnancy rates significantly compared to the clinical touch method.

A meta-analysis of ultrasound-guided versus clinical touch embryo transfer

OBJECTIVE

To determine the relative efficacy of ultrasound-guided embryo transfer and embryo transfer by clinical touch alone.

DESIGN

Systematic review and meta-analysis of randomized, controlled trials comparing ultrasound-guided embryo transfer with embryo transfer by clinical touch alone.

SETTING

Infertility centers providing treatment with in vitro fertilization/embryo transfer.

PATIENT(S)

Women undergoing embryo transfer.

INTERVENTION(S)

Embryo transfer with or without transabdominal ultrasound guidance.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate and embryo implantation rate.

RESULT(S)

A total of eight prospective controlled trials were identified. Of these studies, four were nonrandomized or quasi-randomized and four were genuinely randomized. Meta-analysis demonstrated a significantly increased chance of clinical pregnancy following ultrasound-guided embryo transfer in all studies and in the genuinely randomized subgroup. The embryo implantation rate was also significantly increased following ultrasound-guided embryo transfer.

CONCLUSION(S)

Ultrasound-guided embryo transfer significantly increases the chance of clinical pregnancy and significantly increases the embryo implantation rate.

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.

Embryo transfer by midwife or gynecologist: a prospective randomized study

BACKGROUND

Embryo transfer (ET) in assisted reproduction treatments has traditionally been performed by gynecologists in the Nordic countries. As gynecologists often have a busy schedule, midwives and nurses have become increasingly important in performing the treatment, providing subject information, ultrasound monitoring and assistance at ET. As part of the continuous development of our IVF treatment we have carried out a prospective randomized pilot study where either a midwife or a gynecologist has performed ET. The aim of this study was to see if a skilled IVF midwife could perform ET with similar results to a gynecologist.

METHODS

On the day of oocyte aspiration the subjects were randomized, by means of closed envelopes, for ET to be performed either by a midwife or a gynecologist. A total of 102 subjects were included in the study, 51 for ET by a skilled midwife and 51 by a gynecologist. There were no differences in the groups in respect to ET routine and catheters used.

RESULTS

No significant differences were observed in subject characteristics as regards age, method of pituitary down-regulation or proportion of IVF/ICSI cycles. Similar clinical pregnancy rates between ETs performed by midwives vs. gynecologists, 31% vs. 29%, respectively, were seen. Subject experience as judged by a questionnaire also showed high acceptance of ET by a midwife.

CONCLUSION

The results show that it is a feasible option to allow midwives to carry out ETs.

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.

Ultrasound-guided embryo transfer improves pregnancy rates and increases the frequency of easy transfers

BACKGROUND

Recent reports have suggested that ultrasound (US) guidance during embryo transfer might improve pregnancy rates.

METHODS

A prospective randomized (computer-generated random table) trial was performed to compare embryo transfer under abdominal US guidance (n = 255 women) with clinical touch embryo transfer (n = 260).

RESULTS

The clinical pregnancy rate was 26.3% (67/255) in the US-guided transfer group compared with 18.1% (47/260) in the clinical touch transfer group (P < 0.05). The implantation rate was 11.1% (100/903) in the US group compared with 7.5% (66/884) in the clinical touch group (P < 0.05). US-guided transfer was associated with a decrease in the difficulty of the transfers: 97% of transfers were easy in the US-guided group compared with 81% in the clinical touch group (P < 0.05).

CONCLUSIONS

US-guided embryo transfer increased pregnancy and implantation rates in IVF cycles, as well as the frequency of easy transfers. It is suggested that the decrease in cervical and uterine trauma can play a role in the increase in pregnancy rates associated with US-guided transfer. It is recommended that embryo transfer should be performed under US guidance.

Ultrasound measurement of the uterocervical angle before embryo transfer: a prospective controlled study

BACKGROUND

The study aim was to determine whether moulding the embryo transfer catheter according to the uterocervical angle measured by ultrasound could improve pregnancy and implantation rates.

METHODS

Patients were alternately allocated to one of two groups. In the ultrasound-guided group (n = 320), the catheter was moulded according to the uterocervical angle measured by abdominal ultrasound. In controls (n = 320), embryo transfer was performed using the "clinical feel" method.

RESULTS

Moulding the embryo transfer catheter according to the uterocervical angle significantly increased clinical pregnancy [(OR = 1.57, 95% CI (1.08-2.27)] and implantation rates [(OR = 1.47, 95% CI (1.10-1.96)] compared with the "clinical feel" method. It also significantly reduced difficult transfers [(OR = 0.25, 95% CI (0.16-0.40)] and blood during transfers [OR = 0.71, 95% CI (0.50-0.99)]. Patients with large angles (>60 degrees ) had significantly lower pregnancy rates compared with those with no angle [OR = 0.36, 95% CI (0.16-0.52)].

CONCLUSIONS

Moulding the embryo transfer catheter according to the uterocervical angle measured by ultrasound increases clinical pregnancy and implantation rates and diminishes the incidence of difficult and bloody transfers.

A randomized controlled trial of a soft double lumen embryo transfer catheter versus a firm single lumen catheter: significant improvements in pregnancy rates

BACKGROUND

Embryo transfer has changed little since originally described in 1978. Clinicians rate the type of catheter used as the third most important variable in embryo transfer, but there are no adequately powered randomized trials. We compared the clinical pregnancy rates with the single lumen catheter (TCC) and the double lumen catheter (CC) in a randomized single blind trial.

METHODS

A total of 650 cycles of women from the Adelaide University reproductive medicine units in Australia were included in this trial. Patients were <40 years of age undertaking IVF and embryo transfer. Exclusion criteria were: known uterine abnormality, day 3 FSH >10 IU/l, previous difficult embryo transfer and pre-implantation genetic diagnosis. Cycles were randomized from numbered sealed envelopes immediately prior to embryo transfer with stratification for fresh or frozen cycles.

RESULTS

There was a significantly higher pregnancy rate in the group treated with the CC compared with the TCC catheter [29.6 versus 20.5% per embryo transfer, odds ratio (OR) = 1.63 (95% confidence interval: 1.14-2.30), P = 0.0076]. The point estimate for the OR was similar for fresh and frozen cycles.

CONCLUSIONS

The pregnancy rate was increased by 50% and this justifies the increased cost of the soft double lumen catheter and the training of clinical staff required.

Transvaginal ultrasound-guided embryo transfer improves outcome in patients with previous failed in vitro fertilization cycles

OBJECTIVE

To determine the effect of transvaginal ultrasound-guided ET in IVF cycles performed on patients who had previously failed to conceive from IVF and compare the results to previous cycles where ultrasound guidance was not used.

DESIGN

Retrospective clinical study.

SETTING

Private practice IVF program.

PATIENT(S)

One hundred twenty-nine women undergoing consecutive cycles of IVF where fresh embryos were transferred.

INTERVENTION(S)

Transvaginal ultrasound guidance was used during transfer of embryos.

MAIN OUTCOME MEASURE(S)

Patient age, number of ampules of gonadotropin used, maximum E(2) level, number of oocytes retrieved, number of two pronuclei embryos obtained, number of embryos transferred, mean embryo score, implantation and pregnancy rate.

RESULT(S)

There was no difference in any of the clinical parameters measured in IVF cycles resulting in pregnancy when transvaginal ultrasound-guided ET was used compared to the failed cycles when there was no ultrasound guidance. Of the patients who previously had failed IVF cycles and subsequently had IVF cycles with ultrasound guidance, those who became pregnant had higher mean embryo scores than those who did not become pregnant. Overall implantation and pregnancy rates were higher during the study period when transvaginal ultrasound guidance was used than in the previous 3 years when it was not used.

CONCLUSION(S)

Transvaginal ultrasound-guided ET may be responsible for successful IVF cycles in patients who had previously failed to conceive when embryos were transferred by the clinical touch method. Transvaginal ultrasound guidance may also be responsible for an overall increase in embryo implantation and pregnancy compared to the use of the clinical touch method.

A Wallace malleable stylet for difficult embryo transfer in an in vitro fertilization program: a case-control study

BACKGROUND

The aim of the study was to evaluate the impact of using a Wallace malleable stylet in combination with an Edwards-Wallace embryo replacement catheter in case of difficult embryo transfer (ET).

METHODS

A retrospective case-control study was used. The standard ET procedure at the clinic was to use a single tooth tenaculum, and a speculum to straighten the cervical canal prior to inserting the Edwards-Wallace embryo replacement catheter. In 205 of 2041 (10%) fresh ET difficulties were experienced during ET and a Wallace malleable stylet was used to place the outer catheter sheath correctly. This stylet transfer group was compared with a control transfer group of 410 ET performed just before and after each stylet transfer.

RESULTS

No differences in number of transferred embryos, cleavage stage, or embryo morphology score were found between the two groups. We found no differences in implantation rates (20.7 and 19.2% [95% confidence interval (CI) 0.8-1.5]) or delivery rates (29.3 and 25.4% [CI 0.8-1.8]) between the study and control group.

CONCLUSION

Using a Wallace malleable stylet in combination with an Edwards-Wallace embryo replacement catheter in case of difficult ET has no negative impact on implantation and delivery rates.

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.

The effect of ease of transfer and type of catheter used on pregnancy and implantation rates in an IVF program

PURPOSE

To test the effects of type of embryo transfer catheter, transfer difficulty, and observations after the transfer procedure on pregnancy and implantation rates in an IVF programme.

METHODS

Patients were prepared for IVF using standard protocols. Embryo transfer was performed using either Edwards-Wallace or TDT catheter. The difficulty of transfer was graded by a clinician and biologist. Blood observed inside the catheter after the transfer procedure was scored as endometrial damage. Pregnancy and implantation rates were scored.

RESULTS

Type of embryo transfer catheter and the observation of blood did not significantly affect pregnancy and implantation rates when transfer was performed by a single operator.

CONCLUSIONS

In the hands of experienced, skilled operators, neither choice of transfer catheter and difficulty of transfer nor observations of blood on the transfer catheter caused any significant reduction in outcome to the patient.

Transvaginal ultrasound-guided embryo transfer improves pregnancy and implantation rates after IVF

BACKGROUND

Attempts are constantly being made to improve clinical pregnancy rates after IVF and embryo transfer. Since November 1998, we have gradually been adopting transvaginal ultrasound guidance during embryo transfer. We retrospectively examined the efficacy of this method on pregnancy and implantation rates.

METHODS

The results of 846 cycles from our IVF-embryo transfer programme were analysed and comparisons were made between those carried out using ultrasound guidance and those by the clinical touch method.

RESULTS

Higher pregnancy and implantation rates (28.9 and 15.2% respectively) were found in the group using the transvaginal ultrasound guidance during embryo transfer compared with those in the group using the clinical touch method (13.1 and 7.0% respectively). The differences were statistically significant (P < 0.01). There was no significant difference in ectopic pregnancy rates between the two groups.

CONCLUSION

The use of transvaginal ultrasound-guided embryo transfer significantly improved both pregnancy and implantation rates. Although technically difficult, we suggest its use may maximize the chances of achieving a successful pregnancy outcome.

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.

A postal survey of embryo transfer practice in the UK

In this postal survey a questionnaire was sent to all unit directors in the UK to determine their attitudes to the factors influencing embryo transfer practice. They were requested to rate each step on a scale of 1-10, where 1 was irrelevant and 10 very important. A total of 80 practitioners from 40 units replied. Over 50% of the corresponding practitioners were consultants, 33% were middle-grade clinicians, and 12% were infertility nurse specialists. The factor that got the highest rating was the need for a standardized protocol for all unit staff regarding embryo transfer technique. The second critical factor voted by the respondents was the presence of blood on the embryo transfer catheter. Not touching the uterine fundus was deemed to be the third most important factor while the type of embryo transfer catheter used was a very close fourth. Prolonged bed rest following embryo transfer was voted the least important factor to influence the outcome. The wide variations in practice and choice of catheters encountered in this survey are indications of the divided opinion and lack of concrete evidence on which to base any firm decisions. The need for large clinical studies to assess clearly whether higher pregnancy rates will result from modifications in embryo transfer practice is highlighted.

Influence of position and length of uterus on implantation and clinical pregnancy rates in IVF and embryo transfer treatment cycles

In a prospective study of 807 consecutive women shown to have an apparently normal uterus after hysterosalpingography, hysteroscopy or pelvic ultrasonography prior to IVF or intracytoplasmic sperm injection (ICSI) and embryo transfer, the position and length of the uterine cavity was measured routinely at a pre-treatment mock transfer procedure. The apparent length of the uterine cavity was <7 cm in 128 women (group 1), 7-9 cm in 594 women (group 2) and >9 cm in 85 women (group 3). The uterus was noted to be retroverted in 38. 2% (308) women. The embryo transfer catheter was advanced to 5 mm from the uterine fundus based on the previously determined cavity length in all the embryo transfer procedures at 48 h after oocyte collection. Implantation and clinical pregnancy rates were not significantly different with respect to position of the uterus, difficulties encountered in passage of the catheter, mean age of the women, aetiology or duration of infertility or embryology events. An apparently greater cavity length was seen in older and/or parous women, but the difference was not statistically significant. Although the highest implantation and clinical pregnancy rates were seen in women with a cavity length of 7-9 cm (group 2) the differences were not statistically significant: group 1, 18.9 and 36. 7%; group 2, 21.0 and 46.5%; and group 3, 17.3 and 32.9% respectively. The incidence of ectopic pregnancy per reported clinical pregnancy was highest in group 1 women, being 14.9% (7/47) in comparison with group 2 (1.8%, 5/276) and group 3 (0%, 0/27) (P: < 0.0005), suggesting that the size of the uterus is a critical factor in the aetiology of ectopic pregnancy in IVF/ICSI-embryo transfer.