Comprehensive chromosome screening alters traditional morphology-based embryo selection: a prospective study of 100 consecutive cycles of planned fresh euploid blastocyst transfer.

Objective: To determine how often trophectoderm biopsy and rapid, real-time quantitative polymerase chain reaction (PCR)-based comprehensive chromosome screening (CCS) alters clinical management by resulting in the transfer of a different embryo than would have been chosen by traditional day 5 morphology-based criteria.

Design: Prospective.

Setting: Academic center for reproductive medicine.

Patient(s): Infertile couples (n = 100; mean age 35 ± 4 years) with at least two blastocysts suitable for biopsy on day 5.

Intervention(s): Prior to trophectoderm biopsy for CCS the embryologist identified which embryo would have been selected for traditional day 5 elective single ET.

Main Outcome Measure(s): The risk of aneuploidy in the embryos that would have been selected on day 5 was calculated and compared with the aneuploidy rate of the cohort of all embryos that underwent CCS testing. The aneuploidy risk was compared between age groups.

Result(s): After quantitative PCR-based CCS, 22% (95% confidence interval 15%-31%) of the embryos selected by day 5 morphology were aneuploid, which was lower than the 32% aneuploidy rate of the cohort. Patients ≥35 years had a higher risk of an aneuploid blastocyst being selected by morphology than those <35 years old (31% vs. 14%). Among patients who had selection altered by CCS, 74% (14/19) delivered, including 77% (10/13) after elective single ET. Most patients (77%) had an additional euploid blastocyst vitrified for future use.

Conclusion(s): The CCS results alter embryo selection due to the presence of aneuploidy in embryos with optimal day 5 morphology. Excellent outcomes were obtained when CCS-based selection was different than morphology-based selection.