DuoStim: are we really comparing follicular phase with luteal phase stimulations?

GnRH agonist trigger in poor prognosis patients undergoing a multicycle approach through DuoStim or consecutive stimulations: a SWOT analysis

PURPOSE OF REVIEW

Identify the most recent and significant evidence regarding the ovulation trigger within the framework of a multicycle approach through DuoStim, providing valuable insights for improving treatment strategies in patients with a poor prognosis.

RECENT FINDINGS

The trigger method plays a pivotal role in optimizing in-vitro fertilization (IVF) stimulation, influencing oocyte retrieval and maturation rates, as well as follicle recruitment in consecutive ovarian stimulations such as double stimulation. Decision-making involves multiple factors and, while guidelines exist for conventional stimulation, specific recommendations for the multicycle approach are not well established.

SUMMARY

The different methods for inducing oocyte maturation underscore the need for personalization of IVF protocols. The GnRH agonist trigger induces rapid luteolysis and establishes favorable hormonal conditions that do not adversely affect the recruitment of consecutive follicular waves in the context of DuoStim. It serves as a valid alternative to hCG in freeze-all cycles. This strategy might enhance the safety and flexibility of ovarian stimulations with no impact on oocyte competence and IVF efficacy.

Does dual oocyte retrieval with continuous FSH administration increase the number of mature oocytes in low responders? An open-label randomized controlled trial

STUDY QUESTION

Is there an increase in the total number of metaphase II (MII) oocytes between a conventional ovarian stimulation (OS) and a double uninterrupted stimulation?

SUMMARY ANSWER

There is no increase in the total number of MII oocytes when comparing one conventional OS to a continuous stimulation with double oocyte aspiration.

WHAT IS KNOWN ALREADY

Based on the concept of multiple follicular waves, the combination of two stimulations in the same ovarian cycle has gained interest in patients with a low ovarian reserve. This so-called dual stimulation approach is usually characterized by a discontinuation of FSH administration for ∼5 days and appears to have a favourable impact on the number of retrieved oocytes without affecting the embryo quality or ploidy status. The outcomes of dual uninterrupted OS have not yet been studied.

STUDY DESIGN, SIZE, DURATION

This was an open-label randomized controlled trial (RCT) with superiority design, performed in a single tertiary centre. Subjects were randomized with a 1:1 allocation into two groups between October 2019 and September 2021. All patients underwent a conventional stimulation with recombinant FSH. When two or more follicles of 17 mm were present, the final inclusion criterion was assessed; randomization occurred only in the presence of ≤9 follicles of ≥11 mm. In Group A, ovulation was triggered with hCG, and oocyte retrieval (OR) was performed 34-36 h later, followed by a fresh single or double embryo transfer (SET or DET) on Day 3/5. In Group B, ovulation was triggered with GnRH agonist, followed by another OS, without discontinuation of the FSH administration. In the presence of one or more follicles of ≥17 mm, the second stimulation was completed with hCG. A freeze-all strategy (Day 3/5) was applied for both retrievals, followed by transfer of one or two embryos in an artificially prepared frozen-thawed cycle. In the absence of one or more follicles of ≥17 mm after 13 additional days of stimulation, the second cycle was cancelled. All ORs were executed by a senior fertility specialist who was blinded for the first treatment, and all follicles >10 mm were aspirated, according to routine clinical practice. The primary outcome was the total number of MII oocytes. Patients were followed up until all embryos were transferred, or until live birth was achieved. Other secondary outcomes included the number of cumulus-oocyte complexes (COCs), the number of good quality embryos (Day 3/5), the ongoing pregnancy rate, and gonadotropin consumption.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients between 25 and 40 years old, with an anti-Müllerian hormone level of ≤1.5 ng/ml, antral follicle count of ≤6, or ≤5 oocytes after a previous stimulation, were included. At the start, 70 patients were eligible for participation in the trial, of whom 48 patients fulfilled the final inclusion criterium and were randomized. After drop-out of two patients, 23 patients were randomized to a single round of OS (Group A), and 23 patients were randomized to two uninterrupted rounds of OS (Group B).

MAIN RESULTS AND THE ROLE OF CHANCE

Baseline characteristics were similar between both groups. The cumulative number of COCs and MII oocytes after completion of the second OR was similar in Group A and Group B [5.3 ± 2.7 versus 5.3 ± 3.0 (P = 0.95); 4.1 ± 2.4 versus 4.3 ± 2.7 (P = 0.77)]. Likewise, a comparable number of excellent and good quality embryos was available on Day 3 (3.0 ± 2.0 versus 2.7 ± 2.0; P = 0.63). In Group B, the cancellation rate due to insufficient response to the second round of stimulation was 39.1% (9/23). When focusing on the first stimulation in both groups, there were no significant differences regarding basal FSH, gonadotropin consumption, and the number of preovulatory follicles. After the first OR, the mean number of COC and MII oocytes was significantly higher in Group A (who had hCG triggering), compared to Group B (who had GnRH agonist triggering) [5.3 ± 2.7 versus 3.3 ± 2.2; difference 95% CI (0.54 to 3.45), P = 0.004 and 4.1 ± 2.4 versus 3.0 ± 2.2; difference 95% CI (-0.15 to 2.6), P = 0.05, respectively]. Likewise, the number of excellent and good quality embryos on Day 3 was significantly higher (3.0 ± 2.0 versus 1.9 ± 1.7; P = 0.02) in Group A.

LIMITATIONS, REASONS FOR CAUTION

This study was powered to demonstrate superiority for the number of MII oocytes after dual stimulation. Investigating the impact of dual stimulation on pregnancy rates would have required a larger sample size. Furthermore, the heterogeneity in embryo vitrification and transfer policies precluded a correct comparison of embryologic outcomes between both groups.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first RCT investigating the role of continuous stimulation with double aspiration in low responders. Our results show no statistically significant differences in the cumulative number of MII oocytes between one conventional stimulation with fresh ET and two consecutive stimulations with a freeze-only approach. Furthermore, the observed suboptimal oocyte yield after agonist ovulation triggering in low responders in the dual uninterrupted OS group is a reason for concern and further scrutiny, given that previous RCTs have shown similar outcomes in normal and high responders after hCG and GnRH agonist triggers.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported in part by a research grant from Organon. H.T. received honoraria for lectures and presentations from Abbott, Cooper Surgical, Gedeon-Richter, Cook, Goodlife, and Ferring. L.B. received fees for lectures from Merck & Organon and support for attending ESHRE 2023. M.D.V. reports fees for lectures from Ferring, Merck, Organon, IBSA, Gedeon Richter, and Cooper Surgical and support for attending ASRM 2023. S.M. received honoraria for lectures and presentations from Abbott, Cooper Surgical, Gedeon-Richter, IBSA, and Merck. C.B. was on the Advisory board and received consulting fees from Theramex and received honoraria for lectures and presentations from Abbott, Ferring, Gedeon-Richter, IBSA, and Merck.

TRIAL REGISTRATION NUMBER

NCT03846544.

TRIAL REGISTRATION DATE

19 February 2019.

DATE OF FIRST PATIENT’S ENROLMENT

28 October 2019.

Routine double-ovarian-stimulation (DuoStim) in poor responders lacks rationale, evidence, and follow-up

Double ovarian stimulation (DuoStim), initially only suggested for fertility preservation in cancer patients, is now increasingly also used in routine clinical IVF, especially in poor responders. The claimed rational for this is the alleged existence of multiple follicular waves in a single intermenstrual interval, allowing for retrieval of more oocytes in a single IVF cycle. This commentary argues that this expansion of purpose lacks rationale, evidence, and follow-up. Consequently, we suggest that, unless valid clinical indications have been established, DuoStim be only subject of controlled clinical trials with appropriate experimental consents.

Comparison of blastocyst euploidy rates following luteal versus follicular phase stimulation in a GnRH antagonist protocol: a prospective study with repeated ovarian stimulation cycles

STUDY QUESTION

Is there any difference in the mean number of euploid embryos following luteal phase start (LS) and follicular phase start (FS) of ovarian stimulation?

SUMMARY ANSWER

The mean number of euploid blastocysts is equivalent independent of whether the inseminated oocytes are derived from FS or LS.

WHAT IS KNOWN ALREADY

Starting ovarian stimulation at any time of the cycle ('random-start') is commonly used for emergency fertility preservation in cancer patients. A few retrospective studies have been published evaluating LS in women undergoing ovarian stimulation in the context of IVF, but there is a lack of robust data on the comparative efficacy of LS versus FS.Although 'random start' is commonly used in cancer survivors, few retrospective and uncontrolled studies have been published evaluating luteal phase stimulation in women undergoing ovarian stimulation in the context of IVF. Owing to this evident lack of robust data on the efficacy of LS, guidelines typically recommend the LS approach only for medical reasons and not in the context of IVF.

STUDY DESIGN, SIZE, DURATION

This is a prospective, equivalence study, with repeated stimulation cycles, conducted between May 2018 and December 2021. Overall, 44 oocyte donors underwent two identical consecutive ovarian stimulation cycles, one initiated in the FS and the other in the LS. The primary outcome of the study was to evaluate whether FS and LS in the same patient would result in equivalent numbers of euploid embryos following fertilization of oocytes with the same sperm sample.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Overall, 44 oocyte donors underwent two consecutive ovarian stimulation protocols with 150 μg corifollitropin alpha followed by 200 IU recombinant FSH (rFSH) in a fixed GnRH antagonist protocol. The only difference between the two cycles was the day of initiation of ovarian stimulation, which was in the early follicular phase (FS) in one cycle, and in the luteal phase (LS) in the other. Forty-four oocyte recipients participated in the study receiving a mean of six metaphase II (MII) oocytes from each stimulation cycle (FS and LS). All MIIs were inseminated with the corresponding recipient's partner sperm (which had been previously frozen) or donor sperm, in order to safeguard the use of the same sample for either the FS or LS. Following fertilization and blastocyst culture, all generated embryos underwent genetic analysis for aneuploidy screening (preimplantation genetic testing for aneuploidy).

MAIN RESULTS AND THE ROLE OF CHANCE

FS resulted in a significantly shorter duration of ovarian stimulation (difference between means (DBM) -1.05 (95% CI -1.89; -0.20)) and a lower total additional dose of daily rFSH was needed (DBM -196.02 (95% CI -319.92; -72.12)) compared with LS. The donors' hormonal profile on the day of trigger was comparable between the two stimulation cycles, as well as the mean number of oocytes (23.70 ± 10.79 versus 23.70 ± 8.81) (DBM 0.00 (95% CI -3.03; 3.03)) and MII oocytes (20.27 ± 9.60 versus 20.73 ± 8.65) (DBM -0.45 (95% CI -2.82; 1.91)) between FS and LS cycles, respectively. Following fertilization, the overall blastocyst formation rate was 60.70% with a euploid rate of 57.1%. Comparisons between the two stimulation cycles did not reveal any significance differences in terms of fertilization rates (71.9% versus 71.4%), blastocyst formation rates (59.4% versus 62%) and embryo euploidy rates (56.9 versus 57.3%) for the comparison of FS versus LS, respectively. The mean number of euploid blastocysts was equivalent between the FS (1.59 ± 1.30) and the LS (1.61 ± 1.17), (DBM -0.02 (90%CI -0.48; 0.44)).

LIMITATIONS, REASONS FOR CAUTION

The study was performed in young, potentially fertile oocyte donors who are patients with high blastocyst euploidy rates. Although results may be extrapolated to young infertile women with good ovarian reserve, caution is needed prior to generalizing the results to infertile women of older age.

WIDER IMPLICATIONS OF THE FINDINGS

The current study provides evidence that initiation of ovarian stimulation in the luteal phase in young potentially fertile women may result in a comparable number of oocytes and comparable blastocyst euploidy rates compared with follicular phase stimulation. This may imply that in case of a freeze-all protocol in young patients with good ovarian reserve, clinicians may safely consider initiation of ovarian stimulation during the luteal phase.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by an unrestricted grant from MSD/Organon. N.P.P. has received Research grants and honoraria for lectures from: Merck Serono, MSD/Organon, Ferring Pharmaceuticals, Besins Intenational, Roche Diagnostics, IBSA, Theramex, Gedeon Richter. F.M., E.C., M.R. and S.G. declared no conflict of interests.

TRIAL REGISTRATION NUMBER

The study was registered at Clinical Trials Gov (NCT03555942).