Comparison of pregnancy outcomes in elective single blastocyst transfer versus double blastocyst transfer stratified by age.

OBJECTIVE: To determine whether there is a difference in pregnancy outcomes, stratified by age, between women undergoing elective single blastocyst transfer (eSBT) versus those undergoing double blastocyst transfer (2BT).

DESIGN: Retrospective analysis.

SETTING: University IVF center.

PATIENT(S): A total of 1,141 nondonor IVF cycles in women aged <40 years from January 2004-March 2007.

INTERVENTION(S): None.

MAIN OUTCOME MEASURE(S): Eggs retrieved, embryos cryopreserved, implantation rates, clinical pregnancy rates (PR), live birth rates (LBR), spontaneous abortion rates (SAB).

RESULT(S): Pregnancy outcomes in 52 cycles of women <40 years of age who underwent eSBT were compared with 1,086 cycles of women who underwent 2BT in fresh IVF cycles from January 2004-March 2007. Overall, the eSBT was associated with a statistically significant 92% reduction in the twinning rate (from 25%-2%) while maintaining a high clinical PR (63% in the eSBT group vs. 61% in the 2BT group).

CONCLUSION(S): Women who are <40 years of age undergoing nondonor fresh IVF cycles can electively choose to transfer a single blastocyst for the purpose of significantly reducing their risk of multiples without compromising their PR.