When to Transfer Embryos if There Is Only 1 or 2?

The latest reports suggest that it is better to transfer embryos to the uterus on day five of preimplantation development compared to other days of development, but it is not clear if this stands when there are only one-two embryos obtained in the cycle. Therefore, to address this issue, we performed a retrospective study of such cycles. Our study included all of the stimulated IVF/ICSI cycles performed at our institution in the period between 1 January 2004 and 31 December 2018 in which one-two embryos were obtained in the IVF/ICSI cycle and met our inclusion criteria, and we compared the data between day three and day five embryo transfer (ET). The analysis revealed that the day three ET group of patients was significantly older (p < 0.001), were administered a significantly higher dose of gonadotrophins (p = 0.015), and retrieved a lower mean number of aspirated oocytes per cycle (p < 0.001) and lower mean number of embryos (p < 0.001). The birth rate per ET was significantly higher in the day five ET group (p = 0.045) and further analysis indicated that this could be due the trend observed in a group of patients under 36 years old, while in older patients there was no such difference. To conclude, our retrospective study indicates that it might be better to perform ET on day five instead of day three when there are only one-two embryos obtained in the cycle, but probably only when patients are under 36 years old.

An Endometrial Thickness < 8 mm Was Associated With a Significantly Increased Risk of EP After Freeze-Thaw Transfer: An Analysis of 5,960 Pregnancy Cycles

INTRODUCTION

Endometrium characteristics that are most likely to induce ectopic pregnancy were investigated on the basis of the data of 5,960 pregnant freeze-thaw cycles.

METHODS

A total of 5,960 pregnancy cycles after freeze-thaw embryos transfer were included, with the number of intrauterine and ectopic pregnancies being 5,777 and 183, respectively. Ectopic pregnancy was the primary outcome. Endometrial thickness was the main measured variable. The risk factors of ectopic pregnancy were eventually determined based on univariate analysis and subsequent multiple-stepwise logistic regression analysis.

RESULTS

1. After adjusting for confounders, endometrial thickness could independently predict ectopic pregnancy. The adjusted odd ratios for women with endometrial thickness in the ranges of < 8 mm, 8-9.9 mm, and 10-11.9 mm were 3.270 [95% confidence interval (CI), 1.113-9.605, P = 0.031], 2.758 (95% CI, 0.987-7.707, P = 0.053), and 1.456 (95% CI, 0.502-4.225, P = 0.489), respectively, when compared with those having an endometrial thickness of 12-13.9 mm. 2. Endometrial type and preparation protocol were however not identified as risk factors for ectopic pregnancy.

DISCUSSION

1. After freeze-thaw embryo transfer, risks of ectopic pregnancy were significantly higher when the endometrial thickness was < 8 mm. 2. A thin endometrial thickness could be linked with abnormal endometrial peristaltic waves or abnormal endometrial receptivity. 3. Adequate attention should therefore be paid to patients with a thin endometrial thickness to prevent EP or to achieve early diagnosis during the peri-transplantation period.

Array comparative genomic hybridization analyses of all blastomeres of a cohort of embryos from young IVF patients revealed significant contribution of mitotic errors to embryo mosaicism at the cleavage stage

BACKGROUND

Embryos produced by in vitro fertilization (IVF) have a high level of aneuploidy, which is believed to be a major factor affecting the success of human assisted reproduction treatment. The aneuploidy rate of cleavage stage embryos based on 1-2 biopsied blastomeres has been well-reported, however, the true aneuploidy rate of whole embryos remain unclear because of embryo mosaicism. To study the prevalence of mosaicism in top quality IVF embryos, surplus embryos donated from young patients (aged 28-32) in the assisted reproduction program at Queen Mary Hospital, Hong Kong were used.

METHODS

Thirty-six good quality day 2 embryos were thawed. Out of the 135 blastomeres in these embryos, 121 (89.6%) survived thawing. Twelve of these embryos without lysed blastomeres and which cleaved to at least seven cells after a 24-h culture were dissembled into individual blastomeres, which were analysed by array comparative genomic hybridization and microsatellite marker analysis by fluorescent PCR.

RESULTS

Out of 12 day-3 embryos, 2 (16.7%) were normal, 3 (25%) were diploid/aneuploidy with <38% abnormality, 4 (33.3%) were diploid/aneuploidy mosaic with > =38% abnormality, and three (25%) were mosaic aneuploids. Conclusive chromosomal data were obtained from a high percentage of blastomeres (92.8%, 90/97). Microsatellite marker analysis performed on blastomeres in aneuploid embryos enabled us to reconstruct the chromosomal status of the blastomeres in each cleavage division. The results showed the occurrence of meiotic errors in 3 (25%) of the studied embryos. There were 16 mitotic errors (18.8%, 16/85) in the 85 mitotic divisions undertaken by the studied embryos. The observed mitotic errors were mainly contributed by endoreduplication (31.3%, 5/16), non-disjunction (25%, 4/16) and anaphase lagging (25%, 4/16). Chromosome breakages occurred in 6 divisions (7.1%, 6/85).

CONCLUSIONS

Mosaicism occurs in a high percentage of good-quality cleavage stage embryos and mitotic errors contribute significantly to the abnormality.

Comparison between Cleavage Stage versus Blastocyst Stage Embryo Transfer in an Egyptian Cohort Undergoing in vitro Fertilization: A Possible Role for Laser Assisted Hatching

BACKGROUND

Extended in vitro embryo culture and blastocyst transfer have emerged as essential components of the advanced reproductive technology armamentarium, permitting selection of more advanced embryos considered best suited for transfer.

AIM OF STUDY

The aim of this study was to compare between cleavage stage and blastocyst stage embryo transfer in patients undergoing intracytoplasmic sperm injection, and to assess the role of assisted hatching technique in patients undergoing blastocyst transfer.

PATIENTS AND METHODS

This study was carried out on two groups. Group I: 110 patients who underwent 120 cycles of intracytoplasmic sperm injection with day 2-3 embryo transfer-for unexplained infertility or male factor within the previous 3 years. Their data obtained retrospectively from medical records. Group II: 46 age matched infertile female patients undergoing 51 intracytoplasmic sperm injection cycles for similar causes. Patients in Group II were further subdivided into 2 equal subgroups; Group IIa (23 patients), which had laser assisted hatching and Group IIb (23 patients), which did not have assisted hatching. All patients had an infertility workup including basal hormonal profile, pelvic ultrasound, hysterosalpingogram and/or laparoscope and semen analysis of the patient's partner. All patients underwent controlled ovarian hyperstimulation: Using long protocol of ovulation induction. Laser assisted hatching was done for blastocysts of 23 patients.

RESULTS

Comparison between both groups as regards the reproductive outcome showed a significant difference in pregnancy and implantation rates, both being higher in group II (P < 0.05) Comparison between both subgroups as regards the reproductive outcome showed a highly significant difference in pregnancy and implantation rates, both being higher in Group IIa (P < 0.01). There was also a significantly higher rate of multiple pregnancies among Group IIa (P < 0.05).

CONCLUSION

Blastocyst transfer is a successful and improved alternative for patients with multiple failed in vitro fertilization attempts, associated with a significant increase in pregnancy and implantation rates. Furthermore, laser assisted hatching increases implantation and clinical pregnancy rates.

Blastocyst stage transfer vs cleavage stage embryo transfer

OBJECTIVE

To evaluate the efficacy of blastocyst transfer in comparison with cleavage stage embryo in a similar cohort of women.

DESIGN

Retrospective analysis.

SETTING

University teaching hospital.

MATERIALS AND METHODS

Women aged 35 or less undergoing in vitro fertilization/intracytoplasmic sperm injection between January 2005 and December 2006 were included in the study. When four or more grade 1 embryos were observed on day 3, extended culture till day 5 was undertaken. This policy was compared with a cohort of women who had at least three grade 1 embryos on day 3 and who had undergone a cleavage stage embryo transfer during the time period of January 2002-December 2004. Primary outcome evaluated was implantation rate and clinical pregnancy rate.

RESULTS

Group 1 consisted of 50 women who underwent extended culture and blastocyst transfer. Group 2 comprised of 85 women who had cleavage transfer. The implantation rate for embryos transferred in group 1 was significantly higher than that for embryos transferred on day 3 (40.16% vs 11.43%). The clinical pregnancy rate was also significantly better with blastocyst transfer as compared with cleavage stage transfer (62% vs 29.76%). Significantly fewer embryos were required for transfer at the blastocyst stage compared with day 3 transfer (2.54 vs 3.45).

CONCLUSION

In selected cases, blastocyst transfer with fewer embryos can be performed with high implantation and clinical pregnancy rates. This policy could lead to a reduction in the incidence of higher-order pregnancies.