Objective:

To compare blastulation rates and pregnancy success from embryos cultured in standard “large-box” Sanyo incubators and Miri^® TL Benchtop Multi-room Incubators.

Design:

An IRB approved prospective observation and validation study in a private reproductive technology program.

Materials and Methods:

A total of 65 patients consented and were enrolled into the Time-lapse Morphometry Miri^® Imaging Incubator (TiMMI) study. Mature eggs were fertilized by ICSI and cultured to the blastocyst stage undisturbed in Continuous Single Culture^® (Irvine Scientific) at 37°C in 6% CO2. A minimum of 4 normally fertilized oocytes was required to maintain eligibility. Patients were randomized into control standard large-box incubators or the Miri^® TL. Morphokinetic data was retrospectively evaluated and compared to ploidy status of embryos following PGT-A by NexGen Sequencing. The time points of interest included: time to first cell division (T2), time from 2-cell division to 3-cell (T3) and time to blastulation. Blastocyst formation was defined as an embryo having clear formation of an inner cell mass, scalloped trophectodermal cells and a blastocel cavity of at least 50% of the embryo.

Results:

Post-randomization, the control group consisted of 24 patients with 269 zygotes while 451 zygotes from 41 patients were cultured in the Miri^® TL. Control zygotes developed into 124 (46%) excellent quality blastocysts while 193 (43%) excellent quality blastocysts were identified in the study group. No significant difference (p=.3877) was observed in blastulation rates between incubator types by chi-square analysis. In addition, 43 frozen embryo transfers (13 Control and 30 Study) were performed with no significant difference (p=.8642) in pregnancy success, 53% and 56%, respectively. Pregnancy success was marked by positive fetal cardiac activity at 7 weeks gestation. Morphokinetic data was also analyzed by t-test and did not show a significant difference (p= 0.787) in division times between aneuploid and euploid embryos.

Conclusions:

Previous studies have shown no difference in blastocyst formation, viability and ongoing pregnancy rates between other commercially available time-lapse incubators and standard large-box incubators^1,2. We conclude similar observations in this randomized comparative validation study with the Miri^® TL Incubator and standard large-box incubators. The Miri^® TL provides a novel, safe and non-invasive approach to monitoring the embryos throughout culture. Although blastulation rates, pregnancy success and morphokinetic data in relation to embryo ploidy did not result in significant differences, the added value of time-lapse as a patient engagement tool has yet to be determined.

Support:

ESCO medical provided the Miri Benchtop incubator at no costs for this study. No additional financial compensation was provided to patients or clinic.

¹Cruz, M., Gadea, B., Garrido, N., Pedersen, K.S., Martínez, M., Pérez-Cano, I., Muñoz, M. and Meseguer, M., 2011. Embryo quality, blastocyst and ongoing pregnancy rates in oocyte donation patients whose embryos were monitored by time-lapse imaging. Journal of assisted reproduction and genetics, 28(7), pp.569-573.

²Kirkegaard, K., Hindkjaer, J.J., Grøndahl, M.L., Kesmodel, U.S. and Ingerslev, H.J., 2012. A randomized clinical trial comparing embryo culture in a conventional incubator with a time-lapse incubator. Journal of assisted reproduction and genetics, 29(6), pp.565-572.