The impact of previous conventional stimulation in a DOR
setting
In clinical practices, it is difficult to tell DOR patients they may
never achieve pregnancy despite aggressive treatment. Many DOR patients
would go through conventional IVF first in hopes to obtained oocytes as
more as possible, receiving a ‘heavy’ or a ‘conventional’ stimulation
first. We further discuss if previous conventional IVF has influences on
the outcomes of consequent minimal stimulation IVF.
Minimal stimulation cycles were divided into two groups according to
whether the patient had gone through previous conventional IVF cycles.
We discovered that in patients who had gone through conventional
stimulation IVF, less oocytes were retrieved and poor oocyte quality was
observed in next cycles. So, it is possible that conventional
stimulation would in contrast cause adverse IVF results and is not very
suitable for DOR population. The underlying mechanism is well discussed,
most studies report increased oocyte aneuploidy, embryo mortality, fetal
growth retardation, and congenital abnormalities have been studied at
higher-dose stimulations, and these adverse effects seem to be
cumulative, increasing by each stimulation cycle[19].
Patients in our study were further stratified by previous C-IVF cycles.
We calculated the cumulative pregnancy rate according to previous
cycles. After three cycles of previous IVF cycles, there is a
significant drop in terms of pregnancy rate, indicating that more than
two previous cycles may bring significantly adverse results in DOR
woman. Even though COH has been the most crucial part of IVF treatment,
more studies have proven the advantages of MS-IVF, including higher
safety profile (lowering OHSS rate [20]), higher
singleton birth weight [21] , higher patient
satisfaction and lower financial cost. The aim of MS-IVF is to achieve
“quality” and not “quantity” in terms of oocytes and embryos in the
stimulated cycle.
Indeed, minimal stimulation IVF has been proven to be a safer, better
tolerated, more woman-friendly and affordable way of conducting ovarian
stimulation in IVF cycles.