Maternal physiology and blastocyst morphology are correlated with an inherent difference in peri-implantation human embryo development.

Objective: To determine what patient and embryo characteristics are correlated with the developmental potential of the peri-implantation embryo.

Design: Retrospective study.

Setting: Research laboratory.

Patients: Six hundred fifty-one cryopreserved human blastocysts donated for research with informed patient consent.

Interventions: Not applicable.

Main Outcome Measures: Blastocyst attachment to fibronectin-coated plates, trophectoderm outgrowth area, epiblast cell number, total cell number, human chorionic gonadotropin secretion.

Results: Patients' body mass index, age, follicle-stimulating hormone: luteinizing hormone ratio on menstrual cycle day 3, antral follicle count on menstrual cycle day 3, antimüllerian hormone level on menstrual cycle day 3, and blastocyst morphological grade were correlated with peri-implantation development outcomes. After controlling for good-quality morphological grades, blastocysts from patients of advanced maternal age developed fewer epiblast cells than blastocysts from younger patients.

Conclusions: Extended embryo culture during the peri-implantation period mirrors several disparities in fertility treatment outcome that we see clinically, including those from patients with advanced maternal age, high body mass index, and low ovarian reserve and from embryos with lower-quality morphological grades. This model system may be useful by providing an alternative or more sensitive endpoint assessment in studying patient, clinical, or laboratory factors that may influence preimplantation embryo developmental potential.