Despite considerable advancements over the past
decade in assisted reproduction, poor responders remain
an important challenge. These patients have more
problems in fertilization, embryo quality, and pregnancy.
Poor response to ovarian stimulation occurs in
9-18% of assisted reproductive technique (ART) cycles.
However there is no specific definition for poor
responders, thus a comparison of outcomes from various
protocols is challenging (
Several strategies are available to improve ovarian
stimulation outcome in poor responders, including
increase the dose of the gonatropin that
is being used and administration of gonadotropinreleasing
hormone (GnRH) analogs (agonists or
antagonists). The use of clomiphene citrate, aromatase
inhibitors, growth hormones, transdermal
testosterone, corticosteroids, estradiol or aspirin are recommended as adjuvant therapies (
One of the most successful protocols for ovarian
stimulation of poor responders is the microdose flareup
Our hypothesis is to compare the microdose Gn- RH-a flare-up protocol with the combined stimulatory effect of GnRH agonists and immediate suppression of the GnRH antagonist in a unique protocol that may be a valuable new strategy for ovarian stimulation of poor responders, causing an improved ART outcome. In this study we compare the microdose flare-up protocol to the ultrashort GnRH agonist flare combined with the fixed multidose GnRH antagonist protocol in poor responders undergoing ART cycles.
A total of 120 poor responder women who referred
to the Yazd Fertility and Infertility Center of
Shahid Sadoughi University of Medical Sciences
from June 2007 to July 2009 were enrolled in this
randomized clinical trial. This randomized, controlled
study was approved by the Ethics Committee
of Yazd Fertility and Infertility Center and was
undertaken in accordance with CONSORT guidelines
All included patients had a history of one or more failed IVF cycles with three or less retrieved oocytes. There was no age limitation for participants. We excluded patients with: 1. body mass index (BMI) >30, 2. endocrine or metabolic disorders, 3. history of endometriosis or 4.severe male factor (azspermia).
Patients were randomly allocated into two groups by the use of sealed envelopes. In group I (60 patients) the microdose flare-up regimen was used. Group II (60 patients) were treated with the ultrashort GnRH agonist combined with fixed GnRH antagonist regimens.
All patients received oral contraceptive pills during their previous menstrual cycle. In group I patients received 0.05 mg subcutaneous buserelin (Suprefact, Serono) injections twice daily from the first day of the cycle that continued until the day of the HCG injection. Ovarian stimulation was started from the third day of the patient,s menstrual cycle by intramuscular (IM) injections of HMG (Menogon, Ferring, Germany) at a dose of 300 IU per day. Follicular monitoring began from the ninth day of the cycle by serial vaginal ultrasonography and measurement of serum E2 levels. I.M. injections of 10000 IU HCG (Pregnyl; NV Organon, Oss, The Netherlands) were injected when at least 2 follicles ≥18 mm were observed on ultrasonography.
Group II patients received buserelin (Suprefact, Serono), 0.5 mg/ subcutaneous (SC) per day from the first day of the menstrual cycle, which was continued for three consecutive days. HMG (Menogon, Ferring) at 300 IU per day was started on day three of the cycle. The GnRH antagonist (Cetrorelix, Serono Laboratories, Aubonne, Switzerland) at a dose of 0.25 mg SC per day was started when the dominant follicle size reached a diameter of 14 mm. Follicular monitoring by vaginal ultrasonography and estradiol level measurement began on the ninth day of the cycle. Patients received 10000 IU HCG (Pregnyle, NV Organon, Oss, The Netherlands) when at least 2 follicles that were ≥17-18 mm in diameter were observed by ultrasonography. In both groups oocyte retrieval was performed 34-36 hours after the HCG injection, using a 17 gauge needle under vaginal ultrasonography guidance. Conventional IVF or intracytoplasmic sperm injection (ICSI) was appropriately performed. Fertilization rate was defined as the ratio of number of oocytes with pronuclei observed at least 18 hours after IVF or ICSI to the number of retrieved oocytes. A Labotect catheter (Labotect, Gottingen Germany) was used to transfer the embryos at 48-72 hours following oocyte retrieval. Luteal phase support began with I.M. injections of progesterone in oil (progesterone, Aburaihan Co., Tehran, Iran) at a dose of 100 mg daily on the day of oocyte retrieval and continued until documentation of fetal heart activity by ultrasound. Primary outcome was the clinical pregnancy rate per cycle.
Clinical pregnancy was identified as observation of fetal heart activity by transvaginal ultrasonography performed three weeks after a positive β-hCGv (β-hCG >50 IU/L) two weeks after embryo transfer. This means that the ultrasonography was actually 5 weeks after embryo transfer.
The Statistical Package for Social Sciences (SPSS, version 15.0 for Windows; SPSS Inc., Chicago, IL) was used for data analysis. Student’s ttest and chi-square test were used to detect significant difference (p<0.05) between the variables. All data were expressed as mean ± SD.
We randomly recruited 120 patients, with 60 patients
in each treatment group. There were no significant
differences in mean female age, basal FSH
and duration of infertility between both groups (
Patient’s characteristic in two groups (Mean ± SD)
|Microdose flare-up||GnRH agonist/antagonist||P value|
|33.31 ± 6.02||35.33 ± 4.11||0.139|
|9.91 ± 5.10||8.00 ± 5.32||0.310|
|9.43 ± 2.11||9.91 ± 1.90||0.315|
ART outcome in two groups (Mean ± SD)
|P value||GnRH agonist/ antagonist||Microdose flare-up|
|0.591||44.12 ± 8.20||45.20 ± 6.93|
|0.610||11.60 ± 1.32||11.42 ± 1.61|
|0.802||4.61± 3.53||4.42 ± 3.63|
|0.954||2.44 ± 2.10||2.31 ± 2.41|
|0.458||62 ± 27||58 ± 30|
There were no significant differences between
groups in the number of used gonadotropin ampoules,
the duration of stimulation, the number of
retrieved oocytes, fertilization rate and the number
of transferred embryos. The clinical pregnancy rate
(per cycle) was 10% (
The best stimulation protocol for poor responders
remains controversial. An adequate stimulation
protocol should lead to an acceptable rate of cancellation,
retrieve an adequate number of oocytes, obtain
good quality embryos, and eventually achieve
maximum pregnancy and live birth rates (
In the present study, we compared the microdose
GnRH agonist flare-up and ultrashort GnRH agonist
that was combined with the fixed multidose
GnRH antagonist. According to our findings, poor
responders demonstrated similar outcomes. The
number of used gonadotropin ampoules, duration
of simulation, and the number of retrieved oocytes
were statistically similar in both groups. Fertilization
and pregnancy rates per cycles were similar
in both groups. Antagonist consumption in a poor
responder stimulation protocol is associated with
the possibility of decreasing the number of gonadotropin
ampoules used and reducing the duration
of stimulation. However Scott and Navot have
studied the microdose GnRH flare-up protocol for
low responder women in an ART protocol and reported
a lower cancellation rate, increased number
of retrieved oocytes, and higher pregnancy rates
in these patients (
Orvieto et al. compared an ultrashort GnRH
agonist combined with a flexible multidose GnRH
antagonist and microdose flare-up administration
of GnRH. In contrast to our results, they found
higher numbers of mature oocytes and embryos
in the ultrashort GnRH agonist/ antagonist group.
Pregnancy rate was also significantly higher in this
The successful end-point of ART is to obtain a
live, healthy infant (
Although our findings showed no statistically difference in clinical pregnancy rate and ART outcome between these two protocols, however this new protocol could possibly be considered as a future ovarian stimulation protocol for poor responders. Additional, large randomized prospective studies are recommended to further evaluate the role of agonist-antagonist in poor responder protocols.