ABSTRACT
OBJECTIVE: To investigate whether the morphodynamic characterization of a euploid blastocyst's development allows a higher prediction of a live birth after single-embryo-transfer (SET). DESIGN: Observational cohort study conducted in two phases: training and validation. SETTING: Private in vitro fertilization centers. PATIENT(S): Euploid blastocysts: 511 and 319 first vitrified-warmed SETs from 868 and 546 patients undergoing preimplantation genetic testing for aneuploidies (PGT-A) in the training and validation phase, respectively. INTERVENTION(S): Data collected from time of polar body extrusion to time of starting blastulation, and trophectoderm and inner-cell-mass static morphology in all embryos cultured in a specific time-lapse incubator with a continuous medium. Logistic regressions conducted to outline the variables showing a statistically significant association with live birth. In the validation phase, these variables were tested in an independent data set. MAIN OUTCOME MEASURE(S): Live births per SET. RESULT(S): The average live birth rate (LBR) in the training set was 40% (N = 207/511). Only time of morulation (tM) and trophectoderm quality were outlined as putative predictors of live birth at two IVF centers. In the validation set, the euploid blastocysts characterized by tM <80 hours and high-quality trophectoderm resulted in a LBR of 55.2% (n = 37/67), while those with tM ≥ 80 hours and a low-quality trophectoderm resulted in a LBR of 25.5% (N = 13/51). CONCLUSION(S): Time of morulation and trophectoderm quality are better predictors of a euploid blastocyst's reproductive competence. Our evidence was reproducible across different centers under specific culture conditions. These data support the crucial role of morulation for embryo development, a stage that involves massive morphologic, cellular, and molecular changes and deserves more investigation.
Subject(s)
Blastocyst/pathology , Fertilization in Vitro , Infertility/therapy , Morula/pathology , Single Embryo Transfer , Time-Lapse Imaging , Adult , Embryo Culture Techniques , Embryo Implantation , Embryonic Development , Female , Fertility , Fertilization in Vitro/adverse effects , Humans , Infertility/diagnosis , Infertility/physiopathology , Kinetics , Live Birth , Middle Aged , Predictive Value of Tests , Pregnancy , Pregnancy Rate , Reproducibility of Results , Risk Factors , Rome , Single Embryo Transfer/adverse effects , Spain , Treatment OutcomeABSTRACT
The objective of this study was to identify specific subgroups of recurrent pregnancy loss (RPL) patients of unknown aetiology in whom the selection of chromosomally normal embryos for transfer improves reproductive outcome in preimplantation genetic screening (PGS). A total of 428 PGS cycles were included and chromosomes 13, 15, 16, 18, 21, 22, X and Y were evaluated. In RPL patients < or =37 years, a lower incidence of chromosomal abnormalities (P = 0.0004) and miscarriages (P = 0.0283) was observed, and there were significantly higher pregnancy (P < 0.0384) and implantation (P < 0.0434) rates than in patients >37 years. In the former subset, results showed: (i) significantly higher implantation rates (P = 0.0411) in couples that had experienced a previous aneuploid miscarriage; (ii) similar aneuploidy, pregnancy and implantation rates in couples suffering previous miscarriages during fertility treatments and in those with previous spontaneous pregnancies; (iii) no miscarriages after PGS in couples in whom a fluorescence in-situ hybridization assay showed the male partner's sperm to be abnormal; and (iv) lower implantation rates in couples with > or =5 previous miscarriages, associated with a lower percentage of chromosomally abnormal embryos. It is concluded that PGS is to be strongly recommended when RPL is associated with miscarriages during infertility treatments, chromosomopathy in a previous miscarriage, up to five previous miscarriages and a high incidence of chromosomal abnormalities in spermatozoa.