Elective single blastocyst transfer reduces multiple births
MedWire News: Women aged under 40 years undergoing fresh, nondonor IVF have a reduced risk for multiple births if they receive elective single blastocyst transfer (eSBT) rather than double blastocyst transfer (2BT), study findings show.
The risk for twinning was reduced by 92 percent after eSBT compared with 2BT, without compromising pregnancy rates, the researchers report.
Christine Mullin and colleagues at the New York University Fertility Center, USA, note that multiple births are now considered the most common adverse outcome associated with assisted reproductive technology (ART).
“At the beginning of ART, the focus of IVF success was pregnancy rates,” the team writes.
“It is now time to define new end points for IVF success.”
Pregnancy outcomes were compared between 52 eSBT cycles and 1,086 2BT cycles among women aged <35, 35-37, and 38-39 years.
Pregnancy rates were high in both the eSBT and 2BT groups, at 63 and 61 percent, respectively. And the researchers note that eSBT reduced the twinning rate from 25 to 2 percent.
Overall pregnancy rates, live birth rates, and rates of spontaneous abortion were not significantly different for women treated with eSBT versus 2BT. However, implantation rates were higher among women of all age groups undergoing eSBT.
Mullin and team believe the practice of SBT among appropriate patients will reduce multiple birth rates in the USA.
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By Sarah Guy