Automatic user-independent zona pellucida imaging at the oocyte stage allows for the prediction of preimplantation development

Abstract

Objective: To analyze whether a change in three-dimensional structure of the zona pellucida could indicate suboptimal gamete quality.

Design: Prospective study.

Setting: Women's general hospital.

Patient(s): A total of 72 patients who gave informed consent.

Intervention(s): The birefringence of all oocytes was prospectively analyzed with an automatic user-independent polarization microscopy imaging system.

Main outcome measure(s): Birefringence of the inner zona layer, preimplantation development, implantation, and pregnancy.

Result(s): In approximately one third of all gametes (244/712), the system's automatic detection of the inner zona layer did not succeed. This phenomenon was a negative predictor of compaction (P<0.01), blastulation (P<0.001), and pregnancy (P<0.001). In cases of successful zona imaging, the score based on the birefringence of the inner zona layer was a strong predictor of blastocyst formation but not of embryo quality or pregnancy (P>0.05). Interestingly, antagonist protocol resulted in lower zona scores as compared with the long protocol (P<0.05).

Conclusion(s): Combining the information from both undetected and detected oocytes, zona imaging was a helpful tool in oocyte selection. This knowledge might further help to reduce both the time in culture and the number of concepti considered for transfer.