Effect of delayed versus immediate embryo transfer catheter removal on pregnancy outcomes during fresh cycles

Embryo transfer success: It is in our hands

Embryo transfer (ET) is considered as a critical step in the process of in vitro fertilization. Interestingly, studies have consistently shown significant outcome differences between physicians. Although the outcome of ET is not related to the physician's experience and specifically not different between fellows and attending physicians, certain techniques have been found to affect the success rate. This review summarizes the existing evidence regarding the impact of the individual physician performing ET and the techniques used.

Does rotation during catheter withdrawal in embryo transfer increase pregnancy rates?

BACKGROUND

The aim of this study was to determine whether there is a difference in pregnancy rates between groups that we removed directly and removed by rotating the embryo transfer catheter 360°.

METHODS

The study group consisted of 552 patients who were withdrawn by 360° rotation and 797 patients who were withdrawn without catheter rotation. All patients underwent one or two fresh ETs on day 3 or 5. Groups were compared in terms of cycle characteristics and clinical pregnancy rates.

RESULTS

There were no significant differences in demographic and clinical characteristics of both groups, such as age, body mass index (BMI), duration of infertility, causes of infertility, and basal hormone levels. Clinicals pregnancy rate, in the study group, 48% (265/552) and in the control group, 50.8% (405/797) were similar in both groups. When the implantation rate and miscarriage rate were examined, both groups were found to be similar.

CONCLUSION

It was found that 360° rotation while pulling catheter during embryo transfer had no effect on pregnancy and clinical pregnancy.

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.

Embryo transfer techniques

Embryo transfer is the final and rate-limiting step of the assisted reproductive technique. Few advances have occurred in the last few decades with regard to this procedure. Studies conducted thus far have focused on factors and interventions taking place before, during and after this procedure. These factors are highly varied and range from methods to improve the psychological state of the patients to methods aimed at reducing uterine contractility and methods aimed at optimising the precise transfer of the embryo. The key question is which factors and interventions have thus far been proven to increase pregnancy rates and live birth rates. This paper aims to review the evidence relating to embryo transfer techniques in a systematic manner with a view to provide practical recommendations to practitioners involved in the procedure.

Timing of oocyte retrieval and embryo transfer with pregnancy duration

BACKGROUND

Recent studies have suggested that assisted reproductive technology (ART) may be associated with a shorter pregnancy duration, possibly due to various aspects of the ART procedure. The purpose of this study was to examine whether pregnancy duration is affected by timing of oocyte retrieval and embryo transfer with respect to the first day of the last menstrual period (LMP) among pregnancies achieved through in vitro fertilization with or without intracytoplasmic sperm injection.

METHODS

A retrospective study was conducted at an academic center in Norfolk, Virginia, with analyses based on 294 ART cycles.

RESULTS

Median and interquartile range for pregnancy duration was estimated at 38.2 ± 3.4 weeks. Similarly, median and interquartile ranges for days between LMP and day of oocyte retrieval (27.0 ± 2.0) and between LMP and embryo transfer (29.8 ± 2.2) differed significantly from the standard of 14 days. Timing of oocyte retrieval and embryo transfer with respect to LMP were accelerated among multiple compared with single gestations. For single gestations, pregnancy duration was positively associated with time duration between LMP and embryo transfer (β=0.14, p=0.036). The number of days between oocyte retrieval and embryo transfer was marginally associated with a shorter pregnancy duration in women with multiple gestations (β=3.70, p=0.083). Controlling for patient characteristics, timing of oocyte retrieval and embryo transfer were not significantly associated with pregnancy duration.

CONCLUSIONS

With few exceptions, timing of oocyte retrieval or embryo transfer did not affect pregnancy duration among ART-conceived live births.