Comparative analysis of outcome of morula versus blastocyst transfer

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Introduction: The human embryonic genome is not activated before 4–8 cell stage, so morphological grading on D2/3 does not predict the pregnancy potential of embryo. Sequential media and better culture conditions have made D4/5 embryo transfers (ETs) feasible. Embryos enter the uterus as morulae, which is the rationale behind D4 ET.Aims and Objectives: The aims and objectives of this study were to compare the in vitro fertilization (IVF) outcomes of morula versus blastocyst transfers in fresh IVF intracytoplasmic sperm injection (ICSI) cycles in terms of implantation rates, clinical pregnancy rates (CPRs), and live birth rates (LBRs).Materials and Methods: This is a retrospective study conducted in Bavishi Fertility Institute, Mumbai and Ahmedabad, from January 2017 to September 2018; a total of 349 in vitro fertilization (IVF)-intracytoplasmic sperm injection (ICSI) cycles in females <37 years old, were analyzed, among which 53 were in morula group and 296 in blastocyst group. Cases with severe endometriosis, huge fibroids, severe male factor infertility, and TESA/PESA ICSI were excluded. Outcomes were analyzed statistically in terms of implantation rate, clinical pregnancy rate, and live birth rates.Statistics: Chi-square test (with Yates correction, if required) and unpaired t-test were used for statistical analysis.Results: The implantation rate, CPR, and LBR in morula versus blastocyst group were 34.54% versus 37.79%, 45.28% versus 51.35% and 37.73% versus 45.6%, respectively.Conclusion: The outcome in terms of implantation rate, CPR, and LBR of blastocyst transfer was marginally better than that of morula transfer, but statistically did not reach any significance. Morula transfers done in selective situations offer effective alternative to blastocyst ET without compromising results.