What are you missing without Time-Lapse?
Diana Stein, embryologist for over 30 years and Lab Director of Laniado Hospital-Sanz Medical Center (Israel) and a Miri® Time-Lapse user, had an initial impression after a quick look of the embryo status morning of Day 2 to transfer the embryo on the right, based on its more advanced and slightly better morphology.
However, after review of its time-lapse video she decided to replace it with the one on the left due to Direct Cleavage of the embryo from 2 to 5 cells. Embryo on right continued to develop and was vitrified on Day 4.
Patient delivered a healthy baby girl from D2 replacement of embryo on left. Diana considered this as one of her many “ah-hah” moments.
"That was one of my ah-hah moments"
Limitations of Conventional Embryo Scoring
Conventional embryo classification only scores embryo morphology at a few predefined time points during its pre-implantation development, with the consequent lack of information about what happened between the analyzed time points. There might be unusual cleavage patterns missed out with the conventional scoring that could help in assessing the embryo’s ability to implant. Thus, continual monitoring through time-lapse provides one strategy to collect a complete picture of embryo developmental kinetics.
What are you missing with standard observation at fixed times?
With a time-lapse incubator, you are able to review and annotate accordingly all important events as the embryo develops. Although “abnormal” cleavage events may occur not only at any time but multiple times in the embryos development most occur between standard observation checks. Examples typically seen between D1 and D2 in the embryos development are:
- Direct Cleavage (DCL) ~ 35.1 hpi (26.88—47.29 hpi) with 91% occurring
between 26.88—41.8 hpi.
- Reverse Cleavage (RCL) ~ 37.1 hpi (22.42—59.97 hpi) with 82% occurring
between 22.4—41.5 hpi)
- Multinucleation ~ 32hpi (27—37 hpi)
- Pn Alteration ~ occurs after initial Pn check – time and duration varies 2PN
→ 3PN or 1PN, 3PN → 2PN or 1PN
These “abnormal” events may cause chromosomal abnormalities in the affected embryo which are correlated with decreased implantation, decreased pregnancy rates and spontaneous abortion.