- OBJECTIVE: To evaluate the impact of a poor quality embryo (PQE) during double ET (DET) with a top quality embryo (TQE) on IVF outcome. DESIGN: A review of prospectively collected data. SETTING: Tertiary level fertility clinic. PATIENT(S): All patients undergoing blastocyst transfers as part of fresh IVF (n = 939) and frozen ET (n = 1,009) cycles performed between 2010 and 2016. INTERVENTION(S): Single ET (SET) with TQE (group 1) was set as control and compared with outcomes for SET with PQE (group 2), DET with 2 TQEs (group 3), PQE plus TQE (group 4), and 2 PQE (group 5). MAIN OUTCOME MEASURE(S): Live births and multiple births. RESULT(S): The live birth rates for group 4 were statistically similar to group 1 during fresh IVF (26.5% vs. 33.7%; odds ratio [OR], 0.95; 95% confidence interval [CI] 0.53-1.7) and frozen ET (24.2% vs. 32.7%; OR, 0.75; 95% CI 0.48-1.2), although there was a trend for lower success. Conversely, multiple births were higher in group 4 for fresh IVF (19% vs. 4.7%; OR, 2.9; 95% CI 1.3-6.6) and frozen ET (10.3% vs. 2.6%; OR, 2.4; 95% CI 1.2-4.9). The live birth rates for group 2 (12.2% for fresh IVF and 14.6% for frozen ET) and group 5 (21.2% for fresh IVF and 14% for frozen ET) were lower and for group 3 were higher (40.8% for fresh IVF and 40.3% for frozen ET) when compared with group 1. Multiple births were significantly higher with DET. CONCLUSION(S): This study does not support DET with one PQE along with a TQE, when there is only one TQE and one or more PQEs available for fresh IVF or frozen ET.