Preimplantation genetic testing for aneuploidy: predictive embryonic factors.

PURPOSE: In a preimplantation genetic testing for aneuploidy (PGT-A) cycle, does the blastocyst quality before biopsy, or the day of biopsy, or the embryo hatching status have an impact on either euploidy or the rate of embryo survival after freezing? METHODS: This was a retrospective study including 6130 biopsied blastocysts coming from 1849 PGT-A cycles performed in our center (2016-2022). Embryos were categorized according to the inner cell mass and trophectoderm quality, using Gardner's scoring (excellent: AA; good: AB, BA, BB; poor: AC, CA, BC, CB, CC); the day of biopsy (5 or 6); and their hatching status (fully hatched blastocysts [FHB] or non-fully hatched blastocysts [nFHB]). The independent relationship between each group and both euploidy and survival rate was assessed. RESULTS: Excellent-quality embryos were more euploid than both good- and poor-quality embryos (52.69%, 39.69%, and 26.21%; p < 0.001), and day 5-biopsied embryos were more euploid than day 6-biopsied embryos (39.98% and 34.80%; p < 0.001). Survival rates of excellent-quality (92.26%) and good-quality (92.47%) embryos were higher than survival rates in the poor-quality group (84.61%) (p = 0.011 and p = 0.002). Day 5-biopsied embryos survived better than day 6-biopsied embryos (93.71% vs. 83.69%; p < 0.001) and FHB had poorer survival than nFHB (78.61% vs. 93.52%; p < 0.001). CONCLUSIONS: Excellent-quality and day 5-biopsied embryos are more prone to be euploid than good and poor or day 6-biopsied embryos, respectively. Poor-quality, day 6-biopsied embryos, and FHB have significantly lower survival after biopsy and vitrification.

Cumulus cells have longer telomeres than leukocytes in reproductive-age women.

OBJECTIVE: To investigate whether telomere length (TL) in granulosa cells (GC) or cumulus cells (CC) correlates with TL in leukocytes (L). DESIGN: Prospective noninterventional study. SETTING: Private assisted reproductive technology center. PATIENT(S): Thirty-five egg donors were included in the study. INTERVENTIONS(S): None. MAIN OUTCOME MEASURE(S): Average relative leukocyte telomere length (LTL), cumulus cell telomere length (CCTL), and granulosa cell telomere length (GCTL) measurements from each study subject. RESULT(S): Participants had a mean age of 25.43 ± 4.57 years, antimüllerian hormone level of 1.90 ± 0.92 ng/mL, antral follicle count of 23.29 ± 5.11, and the mean number of mature oocytes retrieved was 23.29 ± 9.13. No significant association between these variables and GCTL, CCTL, or LTL was found. In addition, no correlation was observed between TL measurements of L vs. CC, L vs. GC, or CC vs. GC. Interestingly, CCTL was significantly higher than LTL (1.54-fold), although no significant differences were found between GCTL vs. CCTL or GCTL vs. LTL. CONCLUSION(S): CC from mature follicles have significantly longer telomeres than L, suggesting that the follicular environment could possess different mechanisms to cope against telomere shortening compared with other somatic tissues. Furthermore, these data do not support the utility of telomere DNA measurement in L as an estimate of TL in follicular cells.

Increasing the probability of selecting chromosomally normal embryos by time-lapse morphokinetics analysis.

OBJECTIVE: To study the differences in the cleavage time between chromosomally normal and abnormal embryos and to elaborate an algorithm to increase the probability of noninvasively selecting chromosomally normal embryos. DESIGN: Retrospective cohort study. SETTING: University-affiliated infertility center. PATIENT(S): Preimplantation genetic screening patients (n = 125; n = 77 with ET), including cases of repeated implantation failure or recurrent miscarriage. A total of 504 embryos were analyzed. INTERVENTION(S): Embryo culture within a time-lapse system. MAIN OUTCOME MEASURE(S): Kinetic variables included the time to 2 (t2), 3 (t3), 4 (t4), and 5 (t5) cells as well as the length of the second (cc2 = t3 - t2) and third (cc3 = t5 - t3) cell cycle, the synchrony in the division from 2 to 4 cells (s2 = t4 - t3), and the interval t5 - t2. Implantation and clinical pregnancy rates were also analyzed. RESULT(S): A logistic regression analysis identified t5 - t2 (odds ratio [OR] = 2.853; 95% confidence interval [CI], 1.763-4.616), followed by cc3 (OR = 2.095; 95% CI, 1.356-3.238) as the most relevant variables related to normal chromosomal content. On the basis of these results, an algorithm for embryo selection is proposed to classify embryos from A to D. Each category exhibited significant differences in the percentage of normal embryos (A, 35.9%; B, 26.4%; C, 12.1%; D, 9.8%). CONCLUSION(S): Chromosomally normal and abnormal embryos have different kinetic behavior. On the basis of these differences, the proposed algorithm serves as a tool to classify embryos and to increase the probability of noninvasively selecting normal embryos.

Impact of sperm DNA fragmentation on the outcome of IVF with own or donated oocytes.

A prospective study was performed to assess the impact of sperm DNA fragmentation on the outcome of IVF with own or donated oocytes. The study population included 178 couples (62 cycles of IVF, 116 of intracytoplasmic sperm injection (ICSI)) with own (n=77) and donor (n=101) oocytes. DNA fragmentation was evaluated by TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end labelling assay. Correlation between DNA damage to oocyte fertilization, embryo quality and clinical pregnancy, implantation and miscarriage rates was evaluated. DNA fragmentation was not related to fertilization rates in either IVF (r=0.08) or ICSI (r=-0.04) cycles. DNA fragmentation was similar in patients with <50% embryo utilization rate compared with ≥50%, in cancelled and in embryo transfer cycles and in miscarriages and in successful deliveries. Moreover, DNA fragmentation was similar in pregnant and non-pregnant women as well as in IVF with own or donor oocytes. In the multivariable analysis, the odds ratio of DNA after controlling by age was 1.0. Using a 36% sperm fragmentation threshold, results did not vary. It is concluded that DNA damage was not related to outcomes of IVF or ICSI with own or donor oocytes.