Incidence, Clinical Risk Factors, and Pregnancy Outcomes of Trophectoderm- and Inner Cell Mass-Poor-Quality Blastocysts in Single Blastocyst Transfer Cycles: A Retrospective Cohort Study.

Purpose: To study incidence, clinical risk factors, and pregnancy outcomes of trophectoderm- and inner cell mass-poor-quality blastocysts in single blastocyst transfer cycles. Design: A retrospective cohort study included patients who underwent their first single blastocyst transfer cycle. A multivariate log-binomial regression model with COPY methods was performed. Results: The incidence of having no transferable high-quality blastocysts was 33.8% (15 685/46 433). Maternal age, BMI, infertility duration, cycle number, embryo developmental stage, and transfer strategies are independent risk factors that affect the quality of blastocysts (p < 0.05). After adjusting for 11 confounding factors, the CPR and LBR significantly decreased across the groups in the order of high-grade blastocysts, low TE grade, and low ICM grade. Late-term miscarriage, preterm birth, singleton live birth, low birth weight of singleton, and birth weight of singleton were not statistically different between three groups. Low TE grade blastocysts exhibited significantly higher rates of small gestational sacs compared to high-grade blastocysts, while low ICM grade blastocysts were associated with a significantly higher incidence of small yolk sacs compared to both high-grade blastocysts and those with low TE grade. Conclusions: Differential impacts of blastocyst component quality on early embryonic development.