Conjoined twins post single embryo transfer of a euploid embryo in a frozen embryo transfer cycle.

A patient of advanced maternal age with infertility underwent assisted reproductive technology treatment, followed by a single euploid embryo transfer in a hormonal replacement therapy frozen cycle. The implanted embryo resulted in a thoracophagus conjoined twin pregnancy, joined at the thorax, and was diagnosed at 11 weeks. The pregnancy was terminated. This is the first case of conjoined twins resulting from a euploid embryo transfer in a frozen cycle.