Monozygotic dichorionic-diamniotic twin pregnancy after single embryo transfer at blastocyst stage: A case report

Abstract

Single embryo transfer is highly encouraged on in vi-tro fertilization due to its lower rates of multiple pregnan-cy. Nevertheless, the likelihood of multiple pregnancy is higher when using assisted reproductive technology, prob-ably because of embryo handling. Timing is crucial in the post-fertilization division of a single embryo to establish the amniocity and chorionicity of the gestation. In the case reported a 38 year-old woman, nulligravid, had a single blastocyst implanted, which resulted in monozygotic di-chorionic-diamniotic twins. Despite being rare, there are reports of similar cases questioning the current knowledge on time of embryo division and the impact of assisted re-production.