ABSTRACT
OBJECTIVE: To compare live birth rates (LBRs) and multiple birth rates (MBRs) between elective single-embryo transfer (eSET) and double-embryo transfer (DET) in donor oocyte in vitro fertilization (IVF) treatments in both a cycle-level and clinic-level analysis. METHODS: Donor oocyte IVF treatments performed by US IVF clinics reporting to the Centers for Disease Control and Prevention in 2013-2014 were included in the analysis. Primary outcomes included LBR and MBR. Secondary outcomes included gestational age at delivery (GA) and birth weight (BW) of offspring. These outcomes were evaluated on an individual cycle level as well as on the clinic level. RESULTS: In multivariable models, LBR did not change significantly as clinics utilized eSET more frequently. MBR decreased significantly as utilization of eSET increased, from 39% MBR in clinics that utilized eSET 0-9% of the time to 7% MBR in clinics that used eSET 70% of the time (P < .0001). Mean BW and GA of IVF-conceived offspring both increased as clinics utilized eSET more frequently (2778 to 3185 g [P < .0001] and 37.5 to 38.5 weeks [P = .02] for clinics with the lowest and highest eSET utilization, respectively). CONCLUSIONS: US IVF clinics utilizing eSET with higher frequencies have clinically comparable LBRs and significantly lower MBRs than clinics with lower-frequency eSET utilization. Mean offspring BW and GA increased with higher eSET utilization, further confirming the improved safety of this practice.
