A simple, less invasive stripper micropipetter-based technique for day 3 embryo biopsy

Embryos derived from donor or patient oocytes are not different for in vitro fertilization outcomes when PGT allows euploid embryo selection: a retrospective study

BACKGROUND

At our facilities, patients that received embryos using donor oocyte during in vitro fertilization (IVF), usually have had at least one failed attempt to produce at least one euploid embryo with their own oocytes; however, the current debate between using donor over patient oocytes remains inconclusive. We examined the aneuploidy rate and IVF clinical outcomes from embryos derived from either donor or patient oocytes.

METHODS

Retrospectively, 973 cycles were examined of patients who underwent a standard IVF protocol. Chromosomal content was determined using Pre-implantation Genetic Testing (PGT) by either microarray-comparative genomic hybridization or Next-generation sequencing from either Day 3 (blastocysts) or Day 5 (trophectoderm) embryo biopsies, respectively. Embryo implantation was confirmed by serum β-hCG (> 10 m IU/mL/Day 14), whereas clinical pregnancy by a fetal heartbeat (Week 6.5-8).

RESULTS

Embryos derived from donor oocytes presented with more monosomies than embryos derived from patient oocytes (41.2% vs. 25.4%, p < 0.05, respectively); however, only Trisomy 7 (0.4% vs. 2.3%, p < 0.05) and Trisomy in X (0.7% vs. 2.3%, p < 0.05) were significantly less present when compared to patient oocyte derived embryos. Interestingly, rates for embryo implantation (46.7% vs. 50.8%, p = 0.35), clinical pregnancy (38.5% vs. 43.1%, p = 0.30), and live birth (30.5% vs. 30.5%, p = 0.99) were similar for embryos derived from donor and patient oocytes. These results did not change when adjusted for the number of embryos implanted.

CONCLUSION

Here, we show no significant differences in achieving pregnancy when using donor oocytes. Taking into consideration that aneuploidy rates are > 30% in embryos, independent of the oocyte origin, PGT should be recommended with donor oocytes as well.

Cell extraction automation in single cell surgery using the displacement method

Micromanipulation is the precise in vitro handling and study of individual biological cells, where the smallest error can be disastrous. One such example is the extraction of cellular material from multicellular organisms, such as cells from early stage embryos. In this paper, we propose automation methods for the extraction and retrieval of individual cells from a multicellular organism in vitro using the displacement method. Computer-controlled syringe pumps and micromanipulators combined with custom computer vision algorithms are used for automated cell extraction and retrieval. Automation feasibility is demonstrated through automated controlled extraction of one or two blastomeres from cleavage-stage embryos. Preliminary proof of concept blastomere extraction experiments involving mouse embryos obtained success rates ranging from 72% to 88% for the different extraction tasks: displacement, detection, and retrieval. These automated blastomere extraction experiments demonstrate that automated cell extraction is indeed feasible, but the process may still be improved. To the best of these authors' knowledge, this paper is the first to report the automation of single cell extraction from multicellular organisms using the displacement method, and especially for automated blastomere extraction from cleavage-stage embryos. These methods provide a set of tools for moving towards fully automated single cell surgery procedures.

Assessment of Prostaglandin-Endoperoxide Synthase 2 and Versican gene expression profile from the cumulus cells: association with better in vitro fertilization outcomes

BACKGROUND

Current methods for determining superior embryo quality (morphological assessment) are unable to compensate for poor pregnancy outcomes. Due to the importance of the cumulus-oocyte complex and the value of cumulus cells (CCs) as markers of embryo health, we determined the association between the CCs gene expression of the Prostaglandin-Endoperoxide Synthase 2 (PTGS2) and Versican (VCAN) with pregnancy.

METHODS

One hundred forty-nine women, suffering from infertility and undergoing IVF, were included in this study (age: 29-46 years; BMI = 25.5 ± 5.0 kg/m²). Patients underwent a standard IVF protocol. CCs were isolated during oocyte retrieval, and their RNA was isolated using Trizol. The mRNA expression of PTGS2, VCAN, and L19 was measured by qPCR. The PVL index, (PTGS2 + VCAN)*L19_normalized, was determined for each oocyte. Clinical pregnancy was confirmed by β-hCG and the presence of a fetal heartbeat. Associations were determined by ROC curves or logistic regression.

RESULTS

There was no correlation between the PVL index and morphological scores. Using only single embryo transfers (SETs), we determined that the PVL index was associated with pregnancy (β-hCG: AUC = 0.87, 95%CI: 0.74-1.00) with an optimal cutoff value of 58.2. Using the complete cohort (consisting of SETs, and patients with 2, 3, or 4 embryos transferred), the presence of at least one embryo with a PVL index score ≥ 58.2 was associated with a greater probability of achieving pregnancy (β-hCG: odds ratio = 17.15, 95%CI: 6.82-43.18, p < 0.001).

CONCLUSION

Transferring at least one embryo with a PVL index score ≥ 58.2, generates a higher chance of achieving pregnancy.

Whole Genome Amplification of Day 3 or Day 5 Human Embryos Biopsies Provides a Suitable DNA Template for PCR-Based Techniques for Genotyping, a Complement of Preimplantation Genetic Testing

Our objective was to determine if whole genome amplification (WGA) provides suitable DNA for qPCR-based genotyping for human embryos. Single blastomeres (Day 3) or trophoblastic cells (Day 5) were isolated from 342 embryos for WGA. Comparative Genomic Hybridization determined embryo sex as well as Trisomy 18 or Trisomy 21. To determine the embryo's sex, qPCR melting curve analysis for SRY and DYS14 was used. Logistic regression indicated a 4.4%, 57.1%, or 98.8% probability of a male embryo when neither gene, SRY only, or both genes were detected, respectively (accuracy = 94.1%, kappa = 0.882, and p < 0.001). Fluorescent Capillary Electrophoresis for the amelogenin genes (AMEL) was also used to determine sex. AMELY peak's height was higher and this peak's presence was highly predictive of male embryos (AUC = 0.93, accuracy = 81.7%, kappa = 0.974, and p < 0.001). Trisomy 18 and Trisomy 21 were determined using the threshold cycle difference for RPL17 and TTC3, respectively, which were significantly lower in the corresponding embryos. The Ct difference for TTC3 specifically determined Trisomy 21 (AUC = 0.89) and RPL17 for Trisomy 18 (AUC = 0.94). Here, WGA provides adequate DNA for PCR-based techniques for preimplantation genotyping.