Selection of high-quality and viable blastocysts based on timing of morula compaction and blastocyst formation.

Yoshihisa Harada,Tomoyo Maeda,Shinichiro Okano,Toshitaka Horiuchi,Reiko Shiba,Masayuki Kinutani,Emi Fukunaga

doi:10.1002/rmb2.12302

Abstract

PurposeThe time‐lapse system is a device that allows continuous monitoring without removing embryos from the incubator. Using a time‐lapse system, we retrospectively investigated cleavage speed time points as potential indicators for selecting high‐quality viable blastocysts.MethodsThis study included 963 zygotes of two pronuclei retrieved from 196 patients between January 2015 and December 2016. All embryos in culture were monitored by time‐lapse after intracytoplasmic sperm injection. Of 492 blastocysts developed in vitro, 128 vitrified‐warmed single blastocyst transfers were classified into pregnancy and non‐pregnancy groups, and the parameters were compared.ResultsIn the pregnancy group, timing of both morula compaction and regular blastocyst formation was significantly faster than in the non‐pregnancy group. Furthermore, the optimal cutoff values for compacted morula (94.9 hours) and regular blastocyst (113.9 hours) were determined using the receiver operator characteristic curve analysis. Embryos that formed compacted morulae within 94.9 hours and developed into regular blastocysts within 113.9 hours were associated with a significantly higher pregnancy rate than those that did not (44.4% vs 16.0%).ConclusionThe timing of morula compaction and regular blastocyst formation is important as an indicator of high‐quality blastocysts to increase odds for pregnancy after embryo transfer.

Highlights

In many in vitro fertilization (IVF) clinics, blastocyst transfers have been performed that involve selection of high‐quality embryos, leading to improved implantation rates
The timing of morula compaction and regular blastocyst formation was significantly different between the two groups (P < .01, Mann‐Whitney U test)
3.3 | Clinical pregnancies and live births based on time‐lapse selection criteria: morula compaction within 94.9 hours and regular blastocyst formation within 113.9 hours

Summary

| INTRODUCTION

In many in vitro fertilization (IVF) clinics, blastocyst transfers have been performed that involve selection of high‐quality embryos, leading to improved implantation rates. If multiple blastocysts are obtained from in vitro culture, high‐quality blastocysts must be selected for the best odds of continued embryo fetal development. Objective indicators are needed for better predictive criteria for selecting high‐quality blastocysts in ART. Using a time‐lapse system, the morphokinetics of embryos and the division speed both can be measured This ap‐ proach enables the noninvasive objective assessment of high potential embryos and provides a tool for predicting embryo devel‐ opment and implantation. Many reports have demonstrated the usefulness of time‐lapse, but several of these studies have predicted embryo development in early cleavage,[8-11] with few reports addressing blastocyst selection from in vitro culture.[12]. The purpose of this study was to establish an objective indicator of high‐quality blastocysts using time‐lapse monitoring. We retrospectively evalu‐ ated the relationship between compaction and blastocyst formation timing based on comparison of data from pregnancy and non‐preg‐ nancy groups

| MATERIALS AND METHODS

| DISCUSSION

Findings

DISCLOSURES