Does Advancing Maternal Age Ameliorate the Advantage of Blastocyst Transfer?: The Implantation Rate of Blastocyst Compared to Cleavage Stage Embryo Transfer as a Function of Patient Age

Abstract STUDY QUESTION Are perinatal outcomes different between singleton live births conceived from fresh blastocyst transfer and those following the transfer of fresh cleavage-stage embryos? SUMMARY ANSWER Fresh blastocyst transfer does not increase risks of preterm birth (PTB), low/high birth weight or congenital anomaly and does not alter the sex ratio at birth or prejudice the chance of having a healthy baby. WHAT IS KNOWN ALREADY Extended embryo culture is currently considered the best option for embryo selection, but concerns have been raised about increased risks of preterm delivery and large-for-gestational-age (LGA) babies. STUDY DESIGN, SIZE, DURATION We conducted a retrospective cohort study based on data from the Human Fertilisation and Embryology Authority (HFEA) anonymised and cycle-based dataset in the UK between 1999 and 2011. PARTICIPANTS/MATERIALS, SETTING, METHODS Baseline characteristics were compared between in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) blastocyst-stage and cleavage-stage embryo transfer cycles using the χ2 test for categorical/dichotomised covariates and the Mann–Whitney test for continuous covariates. Statistical significance was set at <0.005. Poisson regression and multinomial logistic regression were used to establish relationships between perinatal outcomes and blastocyst-stage embryo transfer or cleavage-stage embryo transfer. Risk ratios (RRs), adjusted risk ratios (aRRs) and their 99.5% confidence intervals (CIs) were calculated as a measure of strength of associations. Results were adjusted for clinically relevant covariates. A sub-group analysis included women undergoing their first IVF/ICSI treatment. The level of significance was set at <0.05, and 95% CIs were calculated in the sub-group analysis. MAIN RESULTS AND THE ROLE OF CHANCE Of a total of 67 147 IVF/ICSI cycles, 11 152 involved blastocyst-stage embryo(s) and 55 995 involved cleavage-stage embryo(s). The two groups were comparable with regards to the risk of PTB (aRR, 1.00; 99.5% CI, 0.79–1.25), very-preterm birth (VPTB) (aRR, 1.00; 99.5% CI, 0.63–1.54), very-low birth weight (VLBW) (aRR, 0.84; 99.5% CI, 0.53–1.34), low birth weight (LBW) (aRR, 0.92; 99.5% CI, 0.73–1.16), high birth weight (HBW) (aRR, 0.94; 99.5% CI, 0.75–1.18) and very-high birth weight (VHBW) (aRR, 1.05; 99.5% CI, 0.66–1.65). The risk of congenital anomaly was 16% higher in the blastocyst-stage group than in the cleavage-stage group, but this was not statistically significant (aRR, 1.16; 99.5% CI, 0.90–1.49). The chance of having a healthy baby (born at term, with a normal birth weight and no congenital anomalies) was not altered by extended culture (aRR, 1.00; 99.5% CI, 0.93–1.07). Extended culture was associated with a marginal increase in the chance having a male baby in the main cycle-based analysis (aRR, 1.04; 99.5% CI, 1.01–1.09) but not in the sub-group analysis of women undergoing their first cycle of treatment (aRR, 1.04; 95% CI, 1.00–1.08). In the sub-group analysis, the risk of congenital anomalies was significantly higher after blastocyst-stage embryo transfer (aRR, 1.42; 95% CI, 1.12–1.81). LIMITATIONS, REASONS FOR CAUTION This study is limited by the use of observational data and inability to adjust for key confounders, such as maternal smoking status and body mass index (BMI), which were not recorded in the HFEA dataset. As the main analysis was cycle-based and we were unable to link cycles within women undergoing more than one IVF/ICSI cycle, we undertook a sub-group analysis on women undergoing their first treatment cycle. WIDER IMPLICATIONS OF THE FINDINGS Our findings should reassure women undergoing blastocyst-stage embryo transfer. For the first time, we have shown that babies born after blastocyst transfer have a similar chance of being healthy as those born after cleavage-stage embryos transfer. STUDY FUNDING/COMPETING INTEREST(S) The research activity of Dr Nicola Marconi was funded by the scholarship ‘A. Griffini-J. Miglierina’, Fondazione Comunitaria del Varesotto, Provincia di Varese, Italy. The authors do not have any competing interests to disclose. TRIAL REGISTRATION NUMBER N/A

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Pregnancy outcome after blastocyst transfer as compared to early cleavage stage embryo transfer

Human Reproduction ◽

10.1093/humrep/deh694 ◽

2005 ◽

Vol 20 (6) ◽

pp. 1746-1747 ◽

Cited By ~ 1

Author(s):

M. Montag ◽

H. van der Ven

Keyword(s):

Pregnancy Outcome ◽

Embryo Transfer ◽

Blastocyst Transfer ◽

Cleavage Stage ◽

Early Cleavage ◽

Cleavage Stage Embryo ◽

Stage Embryo

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Cumulative live birth rates following blastocyst- versus cleavage-stage embryo transfer in the first complete cycle of IVF: a population-based retrospective cohort study

Human Reproduction ◽

10.1093/humrep/deaa186 ◽

2020 ◽

Vol 35 (10) ◽

pp. 2365-2374

Author(s):

N J Cameron ◽

S Bhattacharya ◽

D J McLernon

Keyword(s):

Embryo Transfer ◽

Live Birth ◽

Oocyte Retrieval ◽

Population Based ◽

Blastocyst Transfer ◽

Cleavage Stage ◽

Complete Cycle ◽

Cumulative Live Birth ◽

Cleavage Stage Embryo ◽

Stage Embryo

Abstract STUDY QUESTION Is there a difference in the odds of a live birth following blastocyst- versus cleavage-stage embryo transfer in the first complete cycle of IVF? SUMMARY ANSWER After adjusting for indication bias, there was not enough evidence to suggest a difference in the odds of live birth following blastocyst- versus cleavage-stage embryo transfer in the first complete cycle of IVF. WHAT IS KNOWN ALREADY Replacement of blastocyst-stage embryos has become the dominant practice in IVF but there is uncertainty about whether this technique offers an improved chance of cumulative live birth over all fresh and frozen-thawed embryo transfer attempts associated with a single oocyte retrieval. STUDY DESIGN, SIZE, DURATION National population-based retrospective cohort study of 100 610 couples who began their first IVF/ICSI treatment at a licenced UK clinic between 1 January 1999 and 30 July 2010. PARTICIPANTS/MATERIALS, SETTING, METHODS Data from the Human Fertilisation and Embryology Authority (HFEA) register on IVF/ICSI treatments using autologous gametes between 1999 and 2010 were analysed. The primary outcome was the live birth rate over the first complete cycle of IVF. Cumulative live birth rates (CLBR) were compared for couples who underwent blastocyst and cleavage transfer, and the adjusted odds of live birth over the first complete cycle were estimated for each group using binary logistic regression. This analysis was repeated within groups of female age, oocytes collected and primary versus secondary infertility. Inverse probability of treatment weighting was used to account for the imbalance in couple characteristics between treatment groups. MAIN RESULTS AND THE ROLE OF CHANCE In total, 94 294 (93.7%) couples had a cleavage-stage embryo transfer while 6316 (6.3%) received blastocysts. Over the first complete cycle of IVF/ICSI (incorporating all fresh and frozen-thawed embryo transfers associated with the first oocyte retrieval), the CLBR was increased in those who underwent blastocyst transfer (56.5%) compared to cleavage-stage embryo transfer (34.8%). However, after accounting for the imbalance between exposures, blastocyst transfer did not significantly influence the odds of live birth over the first complete cycle (adjusted odds ratio: 1.03 (0.96, 1.10)). LIMITATIONS, REASONS FOR CAUTION Limitations of our study include the retrospective nature of the HFEA dataset and availability of linked data up until 2010. We were unable to adjust for some confounders, such as smoking status, BMI and embryo quality, as these data are not collected at national level by the HFEA. Similarly, there may be unknown couple, treatment or clinic variables that may influence our results. We were unable to assess the intended stage of embryo transfer for women who did not have an embryo replaced, and therefore excluded them from our study. Perinatal outcomes were not included in our analyses and would be a useful basis for future study. WIDER IMPLICATIONS OF THE FINDINGS Our findings show that blastocyst-stage embryo transfer may offer an improved chance of live birth in both the first fresh and the first complete cycle of IVF/ICSI compared to cleavage-stage transfer, even in couples with typically poorer prognoses. Where possible, offering blastocyst transfer to a wider range of couples may increase cumulative success rates. STUDY FUNDING/COMPETING INTEREST(S) N.J.C. received a Wolfson Foundation Intercalated Degree Research Fellowship funded by the Wolfson Foundation, through the Royal College of Physicians. This work was supported by a Chief Scientist Office Postdoctoral Training Fellowship in Health Services Research and Health of the Public Research (Ref PDF/12/06) held by D.J.M. The views expressed here are those of the authors and not necessarily those of the Chief Scientist Office or the Wolfson Foundation. The funders did not have any role in the study design; in the collection, analysis and interpretation of data; in the writing of the report; nor in the decision to submit the paper for publication. None of the authors has any conflicts of interest to declare. TRIAL REGISTRATION NUMBER N/A

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Associations of post-warming embryo or blastocyst development with clinical pregnancy in vitrified embryo or blastocyst transfer cycles

Clinical and Experimental Reproductive Medicine ◽

10.5653/cerm.2019.03321 ◽

2020 ◽

Vol 47 (2) ◽

pp. 140-146

Author(s):

Yeon Hee Hong ◽

Jang Mi Lee ◽

Seul Ki Kim ◽

Hye Won Youm ◽

Byung Chul Jee

Keyword(s):

Embryo Transfer ◽

Area Under The Curve ◽

Clinical Pregnancy ◽

Blastocyst Transfer ◽

Cleavage Stage ◽

Blastocyst Development ◽

Embryo Score ◽

Cleavage Stage Embryo ◽

Stage Embryo ◽

The Difference

Objective: To investigate whether the degree of post-warming embryo or blastocyst development is associated with clinical pregnancy in vitrified embryo or blastocyst transfer cycles.Methods: Ninety-six vitrified cleavage-stage embryos and 58 vitrified blastocyst transfer cycles were selected. All transfer cycles were performed from February 2011 to March 2019, and all vitrified embryos or blastocysts were warmed from 4 PM to 6 PM and then transferred the next morning from 9 AM to 10 AM. The scores of the cleavage-stage embryos and blastocysts were assessed at warming and at transfer using the modified Steer method and the Gardner method, respectively. The mean embryo or blastocyst score, score of the single top-quality embryo or blastocyst, and the difference in the score between warming and transfer were compared between nonpregnant and pregnant women.Results: In the cleavage-stage embryo transfer cycles, both the top-quality embryo score at transfer and the difference in the score between warming and transfer were significantly associated with clinical pregnancy. A top-quality embryo score at transfer of ≥60.0 (area under the curve [AUC], 0.673; 95% confidence interval [CI], 0.531–0.815) and a difference in the score between warming and transfer of ≥23.0 (AUC, 0.675; 95% CI, 0.514–0.835) were significant predictors of clinical pregnancy. In blastocyst transfer cycles, the top-quality blastocyst score at transfer was the only significant factor associated with clinical pregnancy. A top-quality blastocyst score at transfer of ≥38.3 was a significant predictor of clinical pregnancy (AUC, 0.666; 95% CI, 0.525–0.807).Conclusion: The top-quality embryo score at transfer and the degree of post-warming embryo development were associated with clinical pregnancy in vitrified cleavage-stage embryo transfer cycles. In vitrified blastocyst transfer cycles, the top-quality blastocyst score at transfer was the only significant factor affecting clinical pregnancy.

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