Influence of different oocyte insemination techniques on early and late morphokinetic parameters: retrospective analysis of 500 time-lapse monitored blastocysts

Abstract

The observed 1.5-hour time difference between standard IVF- and ICSI-fertilized embryos is an artificial phenomenon. At the blastocyst stages, however, genuine timing differences arise between IVF- and ICSI-fertilized embryos, possibly related to their different quality. Normalization to a common time point permits the joint analysis of IVF- and ICSI-fertilized embryos, thus increasing the size of studied cohorts.

Blastocyst collapse is not an independent predictor of reduced live birth: a time-lapse study

“…Early (PNf, t2-t9) and late (start of blastulation and full blastocyst) morphokinetic time points were scored in accordance with recently published consensus criteria (25). To determine the degree of blastocyst expansion more objectively, two additional TLM variables (texpB 1 , texpB 2 ) were also introduced (the time point when the horizontal diameter of the expanded blastocyst reached 130 and 160 mm) (26). Annotations were performed retrospectively using EmbryoViewer by two experienced embryologists (J.Y.S.…”

“…and rechecked by a third person (D.B.). To control for different insemination techniques used (34% and 66% of the cohort was fertilized with conventional IVF or ICSI, respectively) static morphokinetic variables were standardized to the common postfertilization time point of pronuclear fading (26)(27)(28).…”

Time-lapse variables and embryo gender: a retrospective analysis of 81 live births obtained following minimal stimulation and single embryo transfer

“…Seven plane focal images were taken and recorded every 20 min shortly after insemination up until a period of approximately 160 h. Early (PNf, t2-t9) and late (full compaction at morula stage, start of blastulation, and full blastocyst) morphokinetic time points were scored in accordance with recently published consensus criteria [28]. To determine the degree of blastocyst expansion more objectively, two additional TLM variables (texpB 1 and texpB 1 and texpB 2 ) were also introduced; the time point when the horizontal diameter of the expanded blastocyst reached 130 and 160 μm, respectively [29]. Annotations were done using EmbryoViewer by two experienced embryologists and re-checked by a third person.…”

The effect of follicle size and homogeneity of follicular development on the morphokinetics of human embryos

“…Many studies have tried to connect, more or less conclusively, embryo development, timing of mitotic divisions, embryo viability and implantation. However, time points indicating precise embryo cleavages were shown to be affected by extrinsic factors such as ovarian stimulation protocols, culture conditions, fertilization method and also by patient-specific factors [23–28]. …”