E. Martínez

Type of chromosome abnormality affects embryo morphology dynamics

OBJECTIVE To study the differences in the cleavage time between types of embryo chromosomal abnormalities and elaborate algorithm to exclude aneuploid embryos according to the likelihood to be euploid. DESIGN Retrospective cohort study. SETTING University affiliated private center. PATIENT(S) Preimplantational genetic screening patients (n = 112) including cases of advanced maternal age, repeated implantation failure, and recurrent miscarriage. A total of 485 embryos were analyzed. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) All biopsied embryos were cultured in an incubator with time-lapse technology, cleavage timing from insemination to day 3 and all kinetic parameters that have been described in previous studies by our group. RESULT(S) Logistic regression analysis were used to identify morphokinetic parameters and some were strongly associated with complex aneuploid embryos; t3 (odds ratio = 0.590, 95% confidence interval 0.359-0.971) and t5-t2 (odds ratio = 0.151, 95% confidence interval 0.082-0.278). CONCLUSION(S) Embryo morphokinetics are affected by chromosome aneuploidy and further analysis of the chromosome content reveals higher differences when the complexity in the chromosome disorders is increased. The use of time-lapse monitoring, although not able to detect an abnormal embryo, may be potentially useful to discard those embryos with high risk of complex chromosomal abnormalities.

Is there a relationship between time-lapse parameters and embryo sex?

OBJECTIVE To study if it is possible to identify embryo sex from embryo cleavage timings. DESIGN Retrospective and observational study. SETTING University-affiliated private fertility center. PATIENT(S) Women undergoing preimplantion genetic diagnosis. INTERVENTION[S): All biopsied embryos were cultured in an Embryoscope incubator with time-lapse technology. MAIN OUTCOME MEASURE(S) Cleavage timing from insemination to day 3 and all kinetic parameters that have been described in previous studies by our group. RESULT(S) The study included 421 embryos from our Compressive Chromosome Screening program, conducted from January 2012 to December 2012. Embryos were grouped according to their sex: male (176 embryos) and female (161 embryos). Chromosomal abnormal rate was similar for the two groups (male 62.5%, female 58.4%). When morphokinetic parameters were separated in different quartiles and grouped, we found statistical differences between male or female embryos. By logistic regression analysis we found that two specific kinetic variables were relevant: second synchrony (>2 hours) and timing of morula formation (80.8-90.9 hours). With the use of these parameters, we propose an algorithm with four different categories reflecting the range from 71% to 42% in the likelihood of an embryo being female. CONCLUSION(S) Embryo development was affected by embryo sex, and the sex ratio could be affected by the embryo selection method for transfer based on kinetic parameters.

Is Assisted Hatching a useful technique in warmed embryo transfers

concentrations (Table 1).We also found that the percentage of embryos falling within the optimal ranges defined for cc2, t5 and s2 were different between the two groups as showed in Table 2. Based on these results we decided to perform a more detailed analysis in order to find the implications of O2 concentration for D3 embryo selection based on kinetic parameters.

Multinucleation on day 2 affects embryos kinetics but it is not correlated with their chromosomal content

Conclusions: Ongoing implantation rates after day-3 and day5/6 vitrification are comparable between SET and DET, therefore SET should be recommended. Vitrification of blastocysts derived from non 8-cell embryos (assessed within fixed time frames) significantly increases ongoing implantation rates, resulting much quicker in a live birth.