J. Dasig

Metabolomic assessment of oocyte viability

The aim of the current study was to evaluate whether near-infrared (NIR) spectroscopy-generated metabolomic data obtained from oocyte culture samples would correlate with nuclear maturity status and derived embryo development. A total of 412 oocyte culture samples were collected from 43 patient cycles. Metabolomic profiles of metaphase I and II oocytes were obtained by NIR spectroscopy and were significantly different from each other and from profiles of prophase I (germinal vesicle) oocytes (P +/- 0.001 at the 95% confidence interval). Additionally, NIR spectroscopic analysis of culture medium of oocytes that developed to grade A embryos on day 3 demonstrated significantly higher viability indices (0.62 +/- 0.23) than those that developed to grades C/D (0.42 +/- 0.26; P < 0.006); and on day 5 grade A (0.37 +/- 0.20) was also higher than grades C/D (0.14 +/- 0.21; P < 0.02). Metabolomic profiles of oocytes that resulted in pregnancy had higher viability indices (0.87 +/- 0.27) than those that did not (0.44 +/- 0.17; P < 0.0001). The results of the current study demonstrate that metabolomic profiling from spent culture medium of the oocyte is related to nuclear maturity, is able to predict embryo development at day 3 and day 5 stages, and relates to embryo viability.

The value of fast blastocoele re-expansion in the selection of a viable thawed blastocyst for transfer

OBJECTIVE To investigate the role of fast blastocoele re-expansion in the selection of viable thawed blastocysts for transfer. DESIGN Retrospective study. SETTING Academic assisted reproductive program. PATIENT(S) Transfer cycles were divided into two groups according to the presence or absence of fast re-expanded blastocysts. In group I (124 cycles), all transferred blastocysts had fast re-expanding blastocoele. In group II (113 cycles), no fast re-expanded blastocysts were included in the transfer. INTERVENTION(S) Blastocyst survival was defined as >50% of cells remaining intact after thaw and re-expansion after culture in vitro for 2-4 hours before transfer. Blastocysts with >or=50% re-expansion were designated as fast re-expanded blastocysts. MAIN OUTCOME MEASURE(S) Percentage of blastomere loss immediately after thaw, degree of blastocoele re-expansion, and clinical outcomes (pregnancy and implantation rates). RESULT(S) The rates of survival and fast blastocoele re-expansion of partially intact blastocysts were significantly reduced as compared with fully intact blastocysts. Significantly higher rates of clinical pregnancy (37.1% vs. 16.8%) and implantation (26.7% vs. 11.3%) were obtained when all transferred blastocysts had fast re-expanding blastocoele as compared with those transfers without fast re-expanded blastocysts included. CONCLUSION(S) Our results showed that blastomere loss of thawed blastocyst was associated with a reduced ability to re-expand. As a discriminative morphologic marker of superior embryo viability, a fast re-expanded blastocyst would be given priority for transfer to better utilize the cryopreserved blastocysts.