Strengths and Limitation
Firstly, it was the first study to make direct comparisons of
ultra-long, long, antagonist and short protocols on IVF/ICSI outcomes.
Secondly, we ascertained ultra-long protocol was a better choice in
fresh ET cycles for severer adenomyosis, and ultra-long or long
protocols were both considerable for milder adenomyosis. Thirdly, we
observed that antagonist and short protocols could decrease time and
economic cost, and the poor pregnancy outcomes in fresh ET cycles could
be reversed by whole embryo frozen and FET strategy.
The limitation of the study was the possible bias of a retrospective
study, however, we developed strict inclusion and exclusion criteria to
minimize the bias. The embryologists assessing embryo quality were
independent of the study and avoided relevant bias. The differences of
baseline parameters existed, therefore, we carried out logistic
regression to adjust relevant parameters and increased the reliability
of results. Of course, prospective studies were needed to verify the
conclusions.