Experience with a patient-friendly, mandatory, single-blastocyst transfer policy: The power of one

Objective: To determine whether a mandatory single-blastocyst transfer (mSBT) algorithm reduced multiple gestation rates without sacrificing clinical pregnancy rates. Design: Retrospective review. Setting: U.S. university-based assisted reproductive technology (ART) program. Patient(s): All women younger than 38 years undergoing their first ART cycle from 2009 to 2010 with ≥4 high-grade embryos on day 3 after oocyte retrieval (patients from 2009 were the "before" group, and patients completing ART under the mSBT policy in 2010 were the "after" group). Intervention(s): mSBT algorithm. Main Outcome Measure(s): Multiple gestation and clinical pregnancy rates. Result(s): Of the qualified patients, 136 women met inclusion criteria (62 from 2009, 74 from 2010). The baseline demographics were similar between the groups. Statistically significantly fewer blastocysts were transferred per patient in 2010 compared with 2009 (1.5 vs. 1.9). The clinical pregnancy rates before (67.7%) or after (63.5%) the mSBT policy were not statistically significantly different. Multiple gestation rates were statistically significantly reduced, from 43.8% (2009) to 14.6% (2010) after the mSBT policy was instituted. More patients from 2010 had ≥1 blastocyst cryopreserved compared with 2009 (52.9% vs. 30.6%). Conclusion(s): A novel single-blastocyst transfer algorithm reduced multiple gestation rates and improved cryopreservation rates without compromising clinical pregnancy rates in good-prognosis patients.