Discussion
Principal findings
For women aged 36 years and older with at least two blastocysts, there
was no significant difference in the odds of cumulative live birth
following single- versus double- blastocyst transfer accounting for
female age and blastocysts quality. Overall, time needed to achieve live
birth did not decrease with transfer of two blastocysts at one time, but
the risk of multiple livebirths and adverse perinatal outcomes did
increase.