Birth weight is associated with inner cell mass grade of blastocysts

Objective: To determine the relationship between blastocyst growth parameters and birth weight. Design: Cohort study. Setting: University-affiliated fertility center. Patient(s): In vitro patients who delivered a singleton after a single-blastocyst transfer. Intervention(s): None. Main Outcome Measure(s): Birth weight adjusted for gestational age at delivery and gender, with adjusted birth weight examined for association with blastocyst scores and grades. Result(s): After standard in vitro fertilization (IVF) and thawed embryo transfers, greater birth weight was associated with a higher inner cell mass grade. The grade of the trophectoderm and stage of the blastocyst did not relate to weight. Conclusion(s): Embryonic growth as early as day 5 can predict the progress of fetal development as measured by birth weight. (C) 2015 by American Society. for Reproductive Medicine.