INTRODUCTION
Gonadotropin releasing hormone (GnRH) analogues are essential in IVF to
prevent a premature LH surge1-4. Inadequate
suppression can cause early ovulation and affect oocyte quality and
embryo development resulting in a low pregnancy rate5
6.
Despite their overall effectiveness,
GnRH analogues are associated with insufficient ovarian response and
cycle cancellation in 5–20% of all IVF cycles7
8. Furthermore,
GnRH analogues have been criticized
as increasing IVF protocol complexity, resulting in increased costs and
the need for an HCG trigger in GnRH
agonist cycles, which increases the risk of ovarian hyperstimulation
syndrome 9.
Concerning the adverse attributes of
GnRH analogues, Kuang et al proposed
the need for pituitary suppression methods that are more convenient,
less costly and safer for patients. When given as cotreatment with
exogenous gonadotropins for IVF, medroxyprogesterone acetate (MPA) was
used in place of GnRH analogues to block the LH surge10. Prior studies
indicate that compared with GnRH analogues, the use of MPA results in
effective pituitary suppression with similar outcomes such as cycle
cancellation rates, oocyte number and quality, fertilization rate,
cleavage rate, blastocyst quality and pregnancy11. Because of the
adverse effects of premature progesterone exposure on the endometrium,
however, progestin cycles require a freeze-all IVF cycle with subsequent
frozen embryo transfer (FET). Additionally, progestin cycles have been
shown to require more gonadotropins compared with short GnRH agonist
cycles . Several investigators have claimed that progestin cycles are
more patient friendly and cost-effective11-17.
Progestins seem to provide higher
pregnancy rates than the short GnRH agonist protocol following
cryopreserved embryo transfers10
11 15.
However, in most trials, the efficacy and reproductive outcomes of PPOS
regimen were compared to short GnRH agonist protocol,
which is now rarely used in many
assisted reproduction programs and also the live birth rate were
reported by per embryo transfer rather than cumulative live birth rates
(CLBRs) which can reflect the real efficacy of ovarian stimulation in
ART 18-21.
Since
many women with normal ovarian reserve are suitable for fresh embryo
transfer in long agonist protocols, whether this would be the case
compared with the more common long GnRH agonist protocol in which fresh
transfer can be accomplished in the majority cases.
Therefore, the aim of the present study was to compare cumulative live
birth rates and time to live birth in women with normal ovarian reserve
following progestin primed ovarian stimulation protocol with long GnRH
agonist protocol.