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Comparative Study
. 2017 May 8;15(1):37.
doi: 10.1186/s12958-017-0253-6.

Pregnancy rates of day 4 and day 5 embryos after culture in an integrated time-lapse incubator

Affiliations
Comparative Study

Pregnancy rates of day 4 and day 5 embryos after culture in an integrated time-lapse incubator

Verena Holschbach et al. Reprod Biol Endocrinol. .

Abstract

Background: The aim of this study was to compare pregnancy rates in patients undergoing IVF/ICSI with embryo transfer after 4 and 5 days of culture in a closed incubation system with integrated time-lapse imaging.

Methods: Out of n = 2207 in vitro fertilization (IVF)/ intracytoplasmic sperm injection (ICSI) cycles performed between January 2011 and April 2016 at a tertiary referral university hospital, a total of n = 599 IVF/ICSI cycles with prolonged embryo culture in an integrated time-lapse system (EmbryoScope© (Vitrolife)) until day 4 or 5 were retrospectively analyzed with regard to embryo morphology and pregnancy rates.

Results: A transfer on day 5 compared to a transfer on day 4 did not result in higher implantation and clinical pregnancy rates (IR 29.4% on day 4 versus 33.0% on day 5, p = 0.310; CPR 45.2% on day 4 versus 45.7% on day 5, p = 1.0). The percentage of ideal embryos transferred on day 4 was comparable to the rate of ideal embryos transferred on day 5 (41.6% versus 44.1%, p = 0.508). However, on day 4 a significantly higher number of embryos was transferred (1.92 on day 4 versus 1.84 on day 5, p = 0.023), which did not result in higher rates of multiple pregnancies.

Conclusions: Pregnancy rates in IVF/ICSI cycles with integrated time-lapse incubation and transfer on day 4 and 5 are comparable. This finding provides the clinician, IVF laboratory and patient with more flexibility.

Trial registration: This study was retrospectively registered by the local ethics committee of the University of Heidelberg on December 19, 2016 (registration number S-649/2016).

Keywords: Blastocyst culture; ICSI; IVF; Morphokinetic parameter; Pregnancy rate; Time-lapse system; embryo selection.

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Figures

Fig. 1
Fig. 1
a Comparison of clinical and ongoing pregnancy rates of day 4 and day 5 embryo transfers. Error bars indicate 95% confidence intervals. b Pregnancy rates in correlation to the number of transferred embryos. SET = single embryo transfer; DET = double embryo transfer; TET = triple embryo transfer. Error bars indicate 95% confidence interval
Fig. 2
Fig. 2
a Percentage of ideal (good quality) embryos transferred on day 4 and 5. Error bars indicate 95% confidence intervals. b Percentage of embryos transferred on day 4 and day 5 with timely development (according to [27]). Error bars indicate 95% confidence intervals. c Developmental distribution of embryos transferred on day 4 and 5. Day 4 = cycles with embryo transfer on day 4; Day 5 = cycles with embryo transfer on day 5

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References

    1. Braude P, Bolton V, Moore S. Human gene expression first occurs between the four- and eight-cell stages of preimplantation development. Nature. 1988;332(6163):459–61. doi: 10.1038/332459a0. - DOI - PubMed
    1. Gardner DK, Lane M, Schoolcraft WB. Physiology and culture of the human blastocyst. J Reprod Immunol. 2002;55(1-2):85–100. doi: 10.1016/S0165-0378(01)00136-X. - DOI - PubMed
    1. Feil D, Henshaw RC, Lane M. Day 4 embryo selection is equal to day 5 using a new embryo scoring system validated in single embryo transfers. Hum Reprod. 2008;23(7):1505–10. doi: 10.1093/humrep/dem419. - DOI - PubMed
    1. Chatot CL, et al. An improved culture medium supports development of random-bred 1-cell mouse embryos in vitro. J Reprod Fertil. 1989;86(2):679–88. doi: 10.1530/jrf.0.0860679. - DOI - PubMed
    1. Gardner DK, Lane M. Culture and selection of viable blastocysts: a feasible proposition for human IVF? Hum Reprod Update. 1997;3(4):367–82. doi: 10.1093/humupd/3.4.367. - DOI - PubMed

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