Clinical practice of embryo transfer

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

PURPOSE

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

DESIGN

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION

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

The Mare: A Pertinent Model for Human Assisted Reproductive Technologies?

Although there are large differences between horses and humans for reproductive anatomy, follicular dynamics, mono-ovulation, and embryo development kinetics until the blastocyst stage are similar. In contrast to humans, however, horses are seasonal animals and do not have a menstrual cycle. Moreover, horse implantation takes place 30 days later than in humans. In terms of artificial reproduction techniques (ART), oocytes are generally matured in vitro in horses because ovarian stimulation remains inefficient. This allows the collection of oocytes without hormonal treatments. In humans, in vivo matured oocytes are collected after ovarian stimulation. Subsequently, only intra-cytoplasmic sperm injection (ICSI) is performed in horses to produce embryos, whereas both in vitro fertilization and ICSI are applied in humans. Embryos are transferred only as blastocysts in horses. In contrast, four cells to blastocyst stage embryos are transferred in humans. Embryo and oocyte cryopreservation has been mastered in humans, but not completely in horses. Finally, both species share infertility concerns due to ageing and obesity. Thus, reciprocal knowledge could be gained through the comparative study of ART and infertility treatments both in woman and mare, even though the horse could not be used as a single model for human ART.

National Survey Highlights the Urgent Need for Standardisation of Embryo Transfer Techniques in the UK

Embryo transfer (ET) is one of the vital steps in the in vitro fertilisation (IVF) process, yet there is wide variation in ET technique throughout the UK, without a nationally approved standardised approach. The aim of this study was to gain contemporaneous information regarding the current clinical ET practice in the UK. Method: A 38-question electronic survey was distributed to the 79 UK Human Fertilisation and Embryology Authority (HFEA) registered clinics performing ETs. Results: In total, 59% (47/79) of units responded, 83% (39/47) performing ultrasound-guided transfers, with 42% (20/47) of units using a tenaculum; 22% (10/45) would proceed with transfer regardless of fluid in the endometrial cavity. In 91% (43/47) of units, embryos were deposited in the upper/middle portion of the uterine cavity, but interpretation of this area ranged from 0.5 to >2 cm from the fundus, with 68% (32/47) allowing patients to mobilise immediately after transfer. In 60% (27/45) of clinics, success rates were based on clinical pregnancy rates (CPR). Conclusion: Within the UK there is a wide range of variability in ET techniques, with >70% of discordance in survey-responses between clinics. Whilst there are areas of good practice, some disadvantageous techniques continue to persist. This survey emphasises the importance of developing a standardised, evidence-based approach to improve ET success rates.

The impact of the modified speculum application technique on the success rates of intrauterine insemination: A randomized controlled study

OBJECTIVE

Intrauterine insemination (IUI) is frequently used to treat patients with ovulation disorders, cervical factor, mild male infertility and unexplained infertility. The aim of this study was to investigate the impact of modified speculum application on the success of IUI in patients with unexplained infertility.

MATERIALS AND METHODS

This prospective randomized study reviewed 219 women who had undergone controlled ovarian hyperstimulation (COH)-IUI treatment. In the modified speculum application group (109 patients with 124 cycles), the screw of the vaginal speculum was loosened after passing the internal os with catheter and the vaginal speculum remained in this position to ensure closure of the cervix during the procedure. In the conventional speculum application group (110 patients with 132 cycles), the screw of the vaginal speculum was not loosened to close the lips of cervix after passing the internal os with the catheter and the vaginal speculum was removed after withdrawal of the insemination catheter. The primary outcome was live birth rate.

RESULTS

The modified and conventional speculum application groups had statistically similar demographic and clinical characteristics. There were no significant differences between the study and the control groups in terms of the clinical pregnancy rate per cycle and per patient (24.1% vs 18.9% and 26.6% vs 22.7%, respectively), as well as the live birth rate per cycle and per patient (19.3% vs 15.1% and 22% vs 18.1% respectively).

CONCLUSION

Applying gentle mechanical pressure on the portio vaginalis of the cervix using a vaginal speculum during IUI does not improve pregnancy and live birth rates in patients with unexplained infertility.

Transmyometrial embryo transfer as a useful method to overcome difficult embryo transfers - a single-center retrospective study

OBJECTIVE

Pregnancy after an embryo transfer depends largely on embryo quality, endometrial receptivity, and the technique used in the embryo transfer. Embryo transfers have been reported as inevitably traumatic and difficult for 5-7% of patients in assisted reproduction treatment. In these cases, transmyometrial embryo transfer should be considered as a suitable method to overcome difficult embryo transfers. The aim of this study was to report our experience with this technique and analyze its causes, results and complications.

METHODS

Since 1993, 39 women (40 cycles of assisted reproductive technology treatment) were submitted to transmyometrial embryo transfers in our center. The procedures were carried out as described by the Towako group.

RESULTS

The enrolled female patients had a mean age of 34 years and a mean baseline FSH level of 6.89 IU/mL. The median number of retrieved oocytes was 7.50 and a mean of 2.63 embryos were transferred. Implantation rate was 9.5%. With respect to clinical results, pregnancy and miscarriage rates were 25% and 30%, respectively. Since there were two twin pregnancies, the live birth rate was 22.5% (9/40). No major complications were reported.

CONCLUSION

Transmyometrial embryo transfer can and should be an option in cases of difficult/impossible transcervical embryo transfer.

[Congenital cervical agenesis: pregnancy after transmyometrial embryo transfer]

Cervical agenesis is a rare congenital pathology linked to an anomaly of development of the Mullerian system. We described a case report about a 22-year old woman, consulting for infertility, who had a complete cervical agenesis. The first evaluation suggested a 46 XX karyotype and a normal ovarian reserve. The surgical examination confirmed the absence of cervix with impossibility of catheterization. She became pregnant thanks to an in vitro fertilization (IVF) with transmyometrial embryo transfer. Caesarean was decided at 36 weeks of gestation (WG) due to spontaneous uterine contractions. An injection of medroxyprogesterone was made after the placenta delivery in order to warning the partum hemorrhage. The ultrasound examination, realized 15 days after caesarean, underlined a good uterine involution. The surgery by cervico-vaginal anastomosis can be offered to patients because it offers chances of spontaneous pregnancies. But this surgery exposes women to a risk of failure, and of severe complications such as pain or infection, and might end in a hysterectomy. By choosing the transmyometrial transfer by vaginal way, the patient was exposed to the risk of spontaneous miscarriage. It was raising the problem of the uterine evacuation. This delivery after 34 WG is encouraging for the infertility by cervical agenesis.

Successful pregnancy following assisted reproduction and transmyometrial embryo transfer in a patient with anatomical distortion of the cervical canal

Abstract Presented is the case report of a patient noted to have gross distortion of the internal cervical canal during her attempt at embryo transfer following an in vitro fertilization with intracytoplasmic sperm injection (IVF-ICSI) procedure. Multiple attempts at cervical dilation were unsuccessful and the patient was ultimately treated by transmyometrial embryo transfer also known as the Towako method. She successfully achieved a singleton pregnancy and delivered at 41 weeks by primary cesarean section because of arrest of cervical dilation. Transmyometrial embryo transfer represents a viable option for patients with cervical stenosis refractory to conventional methods of navigation or severe anatomical distortion of the internal cervical canal.

Successful twin delivery following transmyometrial embryo transfer in a patient with a false uterine cavity

A successful pregnancy is the greatest goal for reproductive medicine. The probability that pregnancy occurs during a cycle of assisted reproduction is a function of multiple factors, of which embryo transfer is one of the most critical steps in these treatments. This article reports a case of successful pregnancy and twin delivery by transmyometrial embryo transfer after IVF in a woman with a neocavity parallel to the uterine cavity, which prevented the transfer of embryos to the correct place. The patient first went to another fertility centre where embryo transfer was impossible to perform because the cervix could not be canalized. Subsequently in this study clinic, after considering the difficulty of inserting a catheter into the endometrial cavity, a trial transfer was performed, which discovered a false route parallel to endometrial cavity. Following a first cycle in which conventional transcervical embryo transfer was performed, a transmyometrial embryo transfer was carried out and the patient became pregnant with twins. In cases where transcervical embryo transfer is very difficult or impossible to perform, the value of transmyometrial transfer is self-evident.

Successful pregnancy in vitrified/warmed blastocyst intrafallopian transfer

OBJECTIVE

To analyze whether the use of blastocyst intrafallopian transfer is a feasible option in a case of repeated difficult ET.

DESIGN

Case report.

SETTING

Public hospital.

PATIENT(S)

Forty-year old nulliparous patient.

INTERVENTION(S)

Transfer of two vitrified/warmed blastocysts into the right tube by means of laparoscopy.

MAIN OUTCOME MEASURE(S)

Successful ET, clinical pregnancy.

RESULT(S)

Successful ET procedure resulting in positive ß-hCG and clinical pregnancy.

CONCLUSION(S)

In cases of repeated difficult ETs (regardless of whether the patient shows cervical adhesions or any type of genital malformations), blastocyst intrafallopian transfer can be a successful alternative approach.

Treatment with oxytocin antagonists before embryo transfer may increase implantation rates after IVF

This report aimed to examine the effects of atosiban on pregnancy outcome after IVF-embryo transfer. A prospective, randomized, placebo-controlled clinical study was performed. A total of 180 women undergoing intracytoplasmic sperm injection who had top-quality embryos were randomly allocated into treatment and control groups. All the patients had infertility due to tubal factor, hormonal-anovulatory disorders, male factor or unexplained reasons. The treatment group received intravenous administration of atosiban before embryo transfer with a total administered dose of 37.5 mg. In the control group, the same number of cycles was performed with placebo medication. The clinical pregnancy rate (PR) per cycle and implantation rate (IR) per transfer were 46.7% and 20.4% in the atosiban-treated group, which were significantly higher than in the control group (28.9% and 12.6%, respectively, P=0.01). The miscarriage rates of groups 1 and 2 were 16.7% and 24.4%, respectively (P=0.01). These results have indicated that atosiban increases the IR and PR after IVF-embryo transfer. These results suggest that atosiban treatment before embryo transfer is effective in priming of the uterus for implantation. This is the first study to investigate the possible contributions of atosiban for improving the PR after IVF-embryo transfer.

Quality management systems in ART: are they really needed? An Australian clinic's experience

As assisted reproductive technology (ART) expanded globally, several countries introduced prescribed requirements for treatment and monitoring of outcomes, as well as a licensing or accreditation requirement. While it is common for ART laboratories to be required to have an effective quality control system, the remainder of the clinic is often under less stringent regulation. Furthermore, when treatment conditions are prescribed, the standards tend to be conservative and clinics may choose to establish their own standards. Total quality management systems are now being used by an increasing number of ART clinics. In Australia and New Zealand, it is now a requirement to have a quality management system in order to be accredited and to help meet customer demand for improved delivery of ART services in these two countries.

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.

Recurrent implantation failure in assisted reproduction: how to counsel and manage. A. General considerations and treatment options that may benefit the couple

Recurrent implantation failure is a distressing phenomenon, both for the infertile couple and for the physician responsible for their treatment. Aetiology is often not clear and treatment options are vague. Particularly when transferred embryos are of good quality, recurrent implantation failure may be attributed to less than optimal embryo transfer technique, pathological lesions of the uterine cavity, the presence of hydrosalpinges, fibroids and endometriosis. Poor embryo quality, especially when repetitive, is a major impediment to successful implantation and cannot be corrected at the present time. Molecular abnormalities at the endometrial level and abnormal embryo-endometrium dialogue may be responsible for some cases of recurrent implantation failure. Furthermore, there may be over- or under-expressed genes that may be related to successful implantation. At the present time, the physician confronted with a couple presenting with recurrent implantation failure should discuss openly the potential causes of this phenomenon, with special emphasis on correctable causes, and offer remedies that are evidence based.

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.