As with the option of stand-alone PhaseI trials, however,
there are limitations with the option of embedded
Phase I trials. For a start, the logistics, procedures and
record keeping with embedded trials would be more
complicated than with stand-alone trials, as there would
be different requirements for different participants
depending upon whether they were pregnant and, for
those who were pregnant, depending upon the stage of
pregnancy. For example, assuring safety during the later
stages of pregnancy, before enrolling pregnant women
during the more vulnerable early stages of pregnancy,
would be logistically more challenging.