The embryo transfer is one of the moments in which the future parents normally aren't present, but they can if they wish. There are, however, moments in which it is obligatory for the intended parents to be present, as it is the case in gamete extraction, if necessary, and delivery.
Read the full article on: Is it Necessary to be Present at the Embryo Transfer of the Surrogate Mother? ( 61).

Sara Salgado
Embryologist
Degree in Biochemistry and Molecular Biology from the University of the Basque Country (UPV/EHU). Master's Degree in Human Assisted Reproduction from the Complutense University of Madrid (UCM). Certificate of University Expert in Genetic Diagnosis Techniques from the University of Valencia (UV).