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.