Alexis Adler

Blastocyst culture selects for euploid embryos: comparison of blastomere and trophectoderm biopsies

Preimplantation genetic diagnosis and screening improves the chances of achieving a viable pregnancy, not only free of undesired single-gene defects but also aneuploidy. In addition, improvements in vitrification provide an efficient means of preserving embryos (blastocysts). By combining trophectoderm biopsy with recent improvements in vitrification methods, only those embryos that have proved themselves viable and potentially more competent are tested. Using array comparative genomic hybridization (aCGH) to assess all 24 chromosomes, aneuploidy rates were compared between day-3 blastomere biopsy and day-5 trophectoderm biopsy. Of those 1603 embryos, 31% were euploid, 62% were aneuploid and 7% not analysable. A significantly larger proportion of embryos were euploid on day-5 biopsy (42%) compared with day-3 biopsy (24%, P<0.0001). The number of euploid embryos per patient was not significantly different. Combining extended culture, trophectoderm biopsy and aneuploidy assessment by aCGH and subsequent vitrification can provide a more efficient means of achieving euploid pregnancies in IVF.

Is Intracytoplasmic Sperm Injection Overused

PURPOSE We determined whether the use of intracytoplasmic sperm injection in couples who previously underwent intracytoplasmic sperm injection cycles elsewhere could be decreased without compromising the pregnancy rate. MATERIALS AND METHODS At our university in vitro fertilization-embryo transfer center we retrospectively analyzed the records of 149 fresh, in vitro fertilization-embryo transfer cycles in patients who underwent intracytoplasmic sperm injection elsewhere and subsequent fertilization by insemination only (all insemination group) or half insemination and half intracytoplasmic sperm injection at our center. We compared fertilization, implantation, clinical pregnancy and live birth rates. RESULTS The fertilization rate was 74% and 73% for the all insemination and the half intracytoplasmic sperm injection groups, respectively. In the latter group 69% of inseminated and 78% of intracytoplasmic sperm injected oocytes were fertilized. No cycle showed complete fertilization failure. No statistically significant difference in the live birth rate was found between the 2 groups. CONCLUSIONS More stringent criteria for intracytoplasmic sperm injection do not compromise the clinical outcome and reasonable fertilization can be achieved whether or not intracytoplasmic sperm injection is performed. Thus, although intracytoplasmic sperm injection is one of the greatest advances in our field, it is overused and should only be done for clinically proven indications.

Deliveries from trophectoderm biopsied, fresh and vitrified blastocysts derived from polar body biopsied, vitrified oocytes

This longitudinal study reports preliminary findings of six patients who underwent first polar body biopsy followed by oocyte vitrification. All oocytes were warmed, inseminated by intracytoplasmic sperm injection and cultured to blastocyst. All suitable blastocysts underwent trophectoderm biopsy for aneuploidy screening, and supernumerary blastocysts were vitrified. Euploid blastocysts were transferred either fresh or in a subsequent programmed cycle. Of the 91 metaphase II oocytes, 30 had euploid first polar bodies. Development to blastocyst was more likely in oocytes with a euploid first polar body (66.7% versus 24.6%; P < 0.001). Nineteen euploid blastocysts were produced: 10 from oocytes with a euploid first polar body and nine from oocytes with an aneuploid first polar body. Five out of six patients (83%) had a live birth or ongoing pregnancy at the time of analysis. Eleven euploid blastocysts have been transferred and seven implanted (64%). Although the chromosomal status of the first polar body was poorly predictive of embryonic ploidy, an association was found between chromosomal status of the first polar body and development to blastocyst. Further study is required to characterize these relationships, but proof of concept is provided that twice biopsied, twice cryopreserved oocytes and embryos can lead to viable pregnancies.