Impact des techniques de transfert sur l’implantation

Evaluation of a strategy for difficult embryo transfers from a prospective series of 2,046 transfers

Objective

To evaluate an embryo transfer strategy for difficult transfers (DiTs).

Design

Prospective, nonrandomized, observational, cohort study

Setting

A hospital fertility center in France.

Patient(s)

Data were collected on all embryo transfers conducted using the strategy between February 2014 and February 2020.

Intervention(s)

Anatomical characteristics that could cause DiT were identified by transvaginal ultrasound and the catheter was adapted accordingly. Transfer was guided by transvaginal ultrasound. After passage through the cervix, a rest period was introduced to allow any contractions to stop before embryo deposition in the uterus.

Main Outcome Measure(s)

The primary criterion was the percentage of pregnancies per transfer (P/T) after an easy transfer (EaT) or a DiT. The secondary criteria included the anatomical causes of DiT and the patients’ levels of discomfort.

Result(s)

Of 2,046 transfers, 257 (12%) were DiTs: minor difficulties (n = 152; 7.4%), major difficulties (n = 96; 4.7%), very significant difficulties (n = 7; 0.3%), or impossible (n = 2; 0.1%). The most common causes of DiTs were endocervical crypts (54%), tortuous cervical canal (36%), and marked uterine anteversions (30%). Several causes were often responsible for DiTs. There was no statistically significant difference in the P/T between the EaTs (n = 1,789, 41%) and all degrees of DiT (n = 257, 37%). In addition, there was no statistically significant difference between the level of patient-reported discomfort in the EaT and DiT groups.

Conclusion(s)

This study demonstrated that an adapted embryo transfer strategy, monitored by transvaginal ultrasound, led to similar pregnancy rates regardless of whether the transfer was easy or difficult.

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.

Transvaginal ultrasound-guided embryo transfer in IVF

OBJECTIVES

To determine whether transvaginal ultrasound-guided embryo transfer is a technique that can be used routinely, whether it improves IVF outcomes and whether it makes difficult transfers easier and more successful.

MATERIAL AND METHOD

Non-randomized retrospective study conducted between 2012 and 2016 in the fertility center of the Diaconesses-Croix St-Simon hospital group. The outcomes of 3910 transfers, performed by 5 senior operators, under transabdominal ultrasound guidance are compared with those of 800 transfers, performed by 1 senior operator under transvaginal ultrasound guidance. The criteria studied are the feasibility of the technique and the percentage of pregnancies per transfer in the two populations described, as well as in the difficult and very difficult transfer populations.

RESULTS

All the transfers were feasible under transvaginal ultrasound guidance without the use of forceps or additional instruments. The percentage of pregnancies per transfer is significantly increased, when the transfer is performed under transvaginal ultrasound guidance compared with that performed under transabdominal ultrasound guidance, in the general population (38%, n=800 vs 30%, n=3910; P 0.0004) and in the reference population characterized by age <38 years and >6 oocytes collected per puncture (45%, n=490 vs 36%, n=1968; P 0.002). The percentage of pregnancies per transfer (P/T) is not significantly different in the populations of easy transfers (n 695, 38% P/T), difficult transfers (n 58, 46% P/T; P=ns) and very difficult transfers (n 47, 34% P/T; P=ns).

CONCLUSIONS

Embryo transfer is a key stage in IVF, in which the quality of performance determines the outcome. In this study, transvaginal ultrasound guidance of the transfer, which is the reference procedure in gynaecological imaging, significantly increases the percentage of pregnancies per transfer, both in the general population and in the reference population, compared with transfers performed under transabdominal ultrasound guidance. Transvaginal ultrasound facilitates the performance of difficult transfers and in particular achieves outcomes in these situations that are not significantly different from those of easy transfers. Visual monitoring of transcervical passage, which is rendered more precise and less traumatic and precision of embryo deposition are the factors that probably account for the improvement in outcomes.

Efficacy of oxytocin antagonist infusion in improving in vitro fertilization outcomes on the day of embryo transfer: A meta-analysis

Objective

Uterine contraction induced by the embryo transfer (ET) process has an adverse effect on embryo implantation. The aim of this study was to determine the effect of oxytocin antagonist supplementation on the day of ET on in vitro fertilization outcomes via a meta-analysis.

Methods

We performed a meta-analysis of randomized controlled trials (RCTs). Four online databases (Embase, Medline, PubMed, and Cochrane Library) were searched through May 2015 for RCTs that investigated oxytocin antagonist supplementation on the day of ET. Studies were selected according to predefined inclusion criteria and meta-analyzed using RevMan 5.3. Only RCTs were included in this study. The main outcome measures were the clinical pregnancy rate, the implantation rate, and the miscarriage rate.

Results

A total of 123 studies were reviewed and assessed for eligibility. Three RCTs, which included 1,020 patients, met the selection criteria. The implantation rate was significantly better in patients who underwent oxytocin antagonist infusion (19.8%) than in the control group (11.3%) (n=681; odds ratio [OR], 1.92; 95% confidence interval [CI], 1.25–2.96). No significant difference was found between the two groups in the clinical pregnancy rate (n=1,020; OR, 1.57; 95% CI, 0.92–2.67) or the miscarriage rate (n=456; OR, 0.76; 95% CI, 0.44–1.33).

Conclusion

The results of this meta-analysis of the currently available literature suggest that the administration of an oxytocin antagonist on the day of ET improves the implantation rate but not the clinical pregnancy rate or miscarriage rate. Additional, large-scale, prospective, randomized studies are necessary to confirm these findings.

Atosiban improves implantation and pregnancy rates in patients with repeated implantation failure

This prospective cohort study examined the effects of atosiban on uterine contraction, implantation rate (IR) and clinical pregnancy rate (CPR) in women undergoing IVF/embryo transfer. The study enrolled 71 women with repeated implantation failure (RIF; no pregnancies from an average of 4.8 previous embryo transfers with a mean of 12 top-quality embryos) undergoing IVF/embryo transfer using cryopreserved embryos. The total atosiban dose was 36.75 mg. The IR per transfer and CPR per cycle were 13.9% and 43.7%, respectively. Before atosiban, 14% of subjects had a high frequency of uterine contractions (≥ 16 in 4 min). The frequency of uterine contractions was reduced after atosiban. This reduction of uterine contractions in all cycles was significant overall (from 6.0 to 2.6/4 min; P<0.01), in cycles with ≥ 16 uterine contractions/4 min at baseline (from 18.8 to 5.1; P<0.01) and in cycles with <16 uterine contractions/4 min (from 3.9 to 2.2; P<0.01). IR and CPR improved in all subjects, irrespective of baseline uterine contraction frequency. This is the first prospective study showing that atosiban may benefit subjects with RIF undergoing IVF/embryo transfer with cryopreserved embryos. One potential mechanism is the reduction in uterine contractility, but others may also contribute. Many women undergoing IVF/embryo transfer do not achieve the outcome that they wish for. In fact, IVF/embryo transfer repeatedly fails for a subgroup of patients. There are limited options available to help these patients with repeat implantation failure (RIF) to become pregnant. This study looks at one potential new treatment option for women who experience RIF. A drug called atosiban is already being used to delay premature labour by inhibiting contractions of the uterus. In this study, atosiban was given at the time of embryo transfer to women undergoing IVF/embryo transfer. Atosiban reduced the number of uterine contractions in these patients and also increased the implantation and pregnancy rates. The pregnancy rate went from zero to 43.7%. The beneficial effects of atosiban were observed not only in patients who had a high frequency of uterine contractions at baseline but also in those who had a low frequency. These findings suggest that atosiban may have other benefits in addition to its effect on contractions of the uterus. More studies are required to find out exactly how atosiban works and to increase the knowledge of its use in patients with RIF undergoing IVF/embryo transfer.

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.

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.