%0 Journal Article
%@ 1477-7827
%A Holschbach, Verena
%A Weigert, Julia
%A Dietrich, Jens Erik
%A Rösner, Sabine
%A Montag, Markus
%A Strowitzki, Thomas
%A Toth, Bettina
%C London
%D 2017
%F heidok:22936
%I BioMed Central
%J Reproductive Biology and Endocrinology
%N 37
%P 1-8
%T Pregnancy rates of day 4 and day 5 embryos after culture in an integrated time-lapse incubator
%U https://archiv.ub.uni-heidelberg.de/volltextserver/22936/
%V 15
%X 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).