Low Ovarian ReserveFLUSHINGNCT07270081
Follicular Flushing Using Double Lumen Needle Versus Direct Aspiration in Low Prognosis Patients According to the POSEIDON Criteria
A study testing follicular flushing and follicular aspiration in people with Low Ovarian Reserve and Poor Response to Ovulation Induction Poseidon Type IV, run by Instituto Bernabeu at 1 site in Spain.
Trial summary
This is a prospective, randomized, controlled clinical trial designed to evaluate whether follicular flushing increases the number of cumulus-oocyte complexes (COCs) retrieved compared to single aspiration in patients with poor ovarian response belonging to Poseidon groups 3 and 4. Read more about this study
- Who is it for?
- Ages Up to 43 years, women only
- Conditions the study is for
- Low Ovarian Reserve, Poor Response to Ovulation Induction Poseidon Type IV, Poor Response to Ovulation Induction
- What is being tested?
- follicular flushing and follicular aspiration
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteSpain
- Study dates
- 1 Jan 2026to 1 Apr 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Up to 43 years
- Women only
- No healthy volunteers
- Child, Adult
Who may be able to join
- Pacientes con baja respuesta ovárica grupos POSEIDON 3 y 4 (< 35 años y RFA <5 y/o AMH < 1.2 ng/ml o > 35 años≥ 35 años y RFA <5 o AMH <1.2 ng/mL respectivamente)
- Pacientes menores o igual a 43 años.
- Índice de Masa Corporal (IMC) de 18-35 kg/m2
- Estimulación ovárica para ICSI
- Presencia y accesibilidad de ambos ovarios.
- Ausencia de patología ovárica
- Cuando se cumplan los criterios de desencadenamiento para la maduración final del ovocito, cada ovario debe contener al menos un folículo mayor o igual a 14 mm.
- Haber dado su consentimiento por escrito.
Who cannot join
- Presence of a single ovary.
- Presence of ovarian pathology.
- Use of conventional IVF as the fertilization method.
Trial locations and contacts
1 site in 1 country.
About this study
This is a prospective, randomized, controlled clinical trial designed to evaluate whether follicular flushing increases the number of cumulus-oocyte complexes (COCs) retrieved compared to single aspiration in patients with poor ovarian response belonging to Poseidon groups 3 and 4.
A total of 40 patients with poor ovarian response belonging to Poseidon groups 3 and 4 will be included. In each patient, one ovary will be randomized to the study technique (follicular flushing), and the other ovary will be randomized to the control technique (single aspiration).
Read the detailed description
This is a prospective, randomized, controlled clinical study designed to evaluate the effect of follicular flushing on the number of cumulus-oocyte complexes (COCs) retrieved, compared to single aspiration, in patients with poor ovarian response classified as Poseidon groups 3 and 4.
A total of 40 patients will be included. All participants will receive a standardized stimulation protocol consistent with current practice for patients diagnosed with low ovarian reserve. After meeting all inclusion criteria, controlled ovarian stimulation will begin within the first four days of the menstrual cycle, using an antagonist protocol in all cases.
Starting on the 6th day of ovarian stimulation, daily administration of a GnRH antagonist at a dose of 0.25 mg (Ganirelix® or Cetrorelix®) will be initiated. Final oocyte maturation will be triggered once at least one follicle reaches a diameter of ≥17 mm, using either 250 μg of recombinant hCG (Ovitrelle®; Merck Serono) or 0.2 mg of triptorelin acetate (Decapeptyl®), or a double trigger. Oocyte retrieval will be performed 36 hours after triggering final oocyte maturation.
On the day of oocyte retrieval, randomization will be performed using a computer-generated randomization list. In each patient, one ovary will be randomly assigned to the control group (single aspiration), and the contralateral ovary will be assigned to the study group (follicular flushing). Simple random allocation will be used. Each patient will be allowed to participate in the study only once.
Oocyte retrieval procedures will be performed by four trained physicians to evaluate the reproducibility and generalizability of the technique. Follicles will be aspirated using 17G needles in both groups. For follicular flushing, the same needle model used for single aspiration (Cook) will be employed. To eliminate dead space, the needle will be prefilled with flushing medium before beginning the procedure. Aspiration pressure will be maintained at 190 mmHg during oocyte retrieval.
In the single aspiration group, after aspirating all follicles, the needle will be rinsed with flushing medium to minimize the risk of oocyte retention inside the needle.
In the follicular flushing group, if no cumulus-oocyte complex (COC) is recovered during the initial aspiration, follicular flushing will be repeated until a COC is obtained, up to a maximum of three flushes. After three flushes, if no COC is retrieved, the procedure will be completed by rinsing with flushing medium to prevent possible oocyte retention within the needle.
The embryologist will immediately inform the physician performing the oocyte retrieval whether a COC has been recovered, in order to determine whether to continue flushing or proceed to the next follicle (open flushing technique).
The duration of the procedure will be recorded from needle insertion to its withdrawal for each ovary in both groups.
- Conditions
- Low Ovarian Reserve, Poor Response to Ovulation Induction Poseidon Type IV, Poor Response to Ovulation Induction
- Being tested
- follicular flushing, follicular aspiration
- Keywords
- Follicular flushing, Poseidon 3 and 4, Poor responder, low ovarian reserve
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
follicular flushingProcedure or surgery
Follicles will be aspirated using 17G needles of the same gauge in both groups. For follicular flushing, the same type of needle used for single aspiration (Cook) will be employed. To eliminate dead space, the needle will be prefilled with flushing medium before starting the procedure. Aspiration pressure will be maintained at 190 mmHg during oocyte retrieval. In the follicular flushing group, if no cumulus-oocyte complex (COC) is recovered during the initial aspiration, follicular flushing will be performed until a COC is obtained, up to a maximum of three times. After three flushes, if no COC is retrieved, the procedure will be completed by rinsing with flushing medium to minimize the possibility of oocyte retention within the needle.
follicular aspirationProcedure or surgery
In the single aspiration group, after aspirating all follicles, the needle will be rinsed with flushing medium to prevent the possibility of oocyte retention within the needle.
| Study group | Role | What they receive |
|---|---|---|
| Single Aspiration Arm | Active comparator | Oocytes will be retrieved from one ovary using single follicular aspiration Receives: Procedure: follicular aspiration |
| Follicular Flushing Arm | Experimental | Oocytes will be retrieved from the contralateral ovary using follicular flushing, with up to three flushes per follicle if no cumulus-oocyte complex is obtained initially Receives: Procedure: follicular flushing |
What is being measured
The primary outcome is the main question the study is designed to answer.
number of cumulus-oocyte complexes
number of cumulus-oocyte complexes (COCs) retrieved after each aspiration
Measured: During the egg retrieval
Secondary outcomes (4)
Oocyte recovery rate
number of oocytes retrieved / number of follicles ≥11 mm on the day of final oocyte maturation trigger
Measured: day of the egg retrieval
Fertilization rate
number of 2PNs / number of MII oocytes
Measured: 1 day after the egg retrieval
Empty follicle rate
zero oocytes retrieved / follicles punctured
Measured: day of the egg retrieval
Procedure time
calculated from needle insertion to its withdrawal for each ovary
Measured: In seconds from needle insertion to its withdrawal for each ovary
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Dec 2025
- Study start1 Jan 2026
- Primary completion1 Apr 2026
- Study completion1 Apr 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Low Ovarian ReserveStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Each participant will serve as her own control. One ovary will be randomized to single aspiration and the contralateral ovary to follicular flushing.
- Masking
- Double blind
- Who is masked
- Participant, Care provider
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Instituto Bernabeu
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dr. Paolo Cirillo, Instituto Bernabeu
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07270081
- Sponsor's protocol ID
- MR47
- Acronym
- FLUSHING
- Status last verified
- Apr 2026
- First submitted
- 17 Nov 2025
- Last updated
- 14 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 14 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Follicular Flushing Using Double Lumen Needle Versus Direct Aspiration in Low Prognosis Patients According to the POSEIDON Criteria
- ClinicalTrials.gov ID
- NCT07270081
- Acronym / sponsor ID
- FLUSHING / MR47
- Conditions
- Low Ovarian Reserve, Poor Response to Ovulation Induction Poseidon Type IV, Poor Response to Ovulation Induction
- Keywords
- Follicular flushing, Poseidon 3 and 4, Poor responder, low ovarian reserve
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Instituto BernabeuUniversity, hospital or other
- Study start
- 1 Jan 2026 (actual)
- Primary completion
- 1 Apr 2026 (actual)
- Study completion
- 1 Apr 2026 (actual)
- First posted
- 8 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a prospective, randomized, controlled clinical trial designed to evaluate whether follicular flushing increases the number of cumulus-oocyte complexes (COCs) retrieved compared to single aspiration in patients with poor ovarian response belonging to Poseidon groups 3 and 4.
A total of 40 patients with poor ovarian response belonging to Poseidon groups 3 and 4 will be included. In each patient, one ovary will be randomized to the study technique (follicular flushing), and the other ovary will be randomized to the control technique (single aspiration).
Detailed description
This is a prospective, randomized, controlled clinical study designed to evaluate the effect of follicular flushing on the number of cumulus-oocyte complexes (COCs) retrieved, compared to single aspiration, in patients with poor ovarian response classified as Poseidon groups 3 and 4.
A total of 40 patients will be included. All participants will receive a standardized stimulation protocol consistent with current practice for patients diagnosed with low ovarian reserve. After meeting all inclusion criteria, controlled ovarian stimulation will begin within the first four days of the menstrual cycle, using an antagonist protocol in all cases.
Starting on the 6th day of ovarian stimulation, daily administration of a GnRH antagonist at a dose of 0.25 mg (Ganirelix® or Cetrorelix®) will be initiated. Final oocyte maturation will be triggered once at least one follicle reaches a diameter of ≥17 mm, using either 250 μg of recombinant hCG (Ovitrelle®; Merck Serono) or 0.2 mg of triptorelin acetate (Decapeptyl®), or a double trigger. Oocyte retrieval will be performed 36 hours after triggering final oocyte maturation.
On the day of oocyte retrieval, randomization will be performed using a computer-generated randomization list. In each patient, one ovary will be randomly assigned to the control group (single aspiration), and the contralateral ovary will be assigned to the study group (follicular flushing). Simple random allocation will be used. Each patient will be allowed to participate in the study only once.
Oocyte retrieval procedures will be performed by four trained physicians to evaluate the reproducibility and generalizability of the technique. Follicles will be aspirated using 17G needles in both groups. For follicular flushing, the same needle model used for single aspiration (Cook) will be employed. To eliminate dead space, the needle will be prefilled with flushing medium before beginning the procedure. Aspiration pressure will be maintained at 190 mmHg during oocyte retrieval.
In the single aspiration group, after aspirating all follicles, the needle will be rinsed with flushing medium to minimize the risk of oocyte retention inside the needle.
In the follicular flushing group, if no cumulus-oocyte complex (COC) is recovered during the initial aspiration, follicular flushing will be repeated until a COC is obtained, up to a maximum of three flushes. After three flushes, if no COC is retrieved, the procedure will be completed by rinsing with flushing medium to prevent possible oocyte retention within the needle.
The embryologist will immediately inform the physician performing the oocyte retrieval whether a COC has been recovered, in order to determine whether to continue flushing or proceed to the next follicle (open flushing technique).
The duration of the procedure will be recorded from needle insertion to its withdrawal for each ovary in both groups.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, care provider)
- Number of arms
- 2
- Model description
- Each participant will serve as her own control. One ovary will be randomized to single aspiration and the contralateral ovary to follicular flushing.
| Arm | Type | Receives |
|---|---|---|
| Single Aspiration Arm | Active comparator | Procedure: follicular aspirationOocytes will be retrieved from one ovary using single follicular aspiration |
| Follicular Flushing Arm | Experimental | Procedure: follicular flushingOocytes will be retrieved from the contralateral ovary using follicular flushing, with up to three flushes per follicle if no cumulus-oocyte complex is obtained initially |
Who may qualify
- Ages
- Up to 43 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (8 listed)
- Pacientes con baja respuesta ovárica grupos POSEIDON 3 y 4 (< 35 años y RFA <5 y/o AMH < 1.2 ng/ml o > 35 años≥ 35 años y RFA <5 o AMH <1.2 ng/mL respectivamente)
Key exclusion criteria (3 listed)
- Presence of a single ovary.
- Presence of ovarian pathology.
- Use of conventional IVF as the fertilization method.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| follicular flushingFollicles will be aspirated using 17G needles of the same gauge in both groups. For follicular flushing, the same type of needle used for single aspiration (Cook) will be employed. To eliminate dead space, the needle will be prefilled with flushing medium before starting the procedure. Aspiration pressure will be maintained at 190 mmHg during oocyte retrieval. In the follicular flushing group, if no cumulus-oocyte complex (COC) is recovered during the initial aspiration, follicular flushing will be performed until a COC is obtained, up to a maximum of three times. After three flushes, if no COC is retrieved, the procedure will be completed by rinsing with flushing medium to minimize the possibility of oocyte retention within the needle. | Procedure or surgery | Follicular Flushing Arm |
| follicular aspirationIn the single aspiration group, after aspirating all follicles, the needle will be rinsed with flushing medium to prevent the possibility of oocyte retention within the needle. | Procedure or surgery | Single Aspiration Arm |
Primary outcome
number of cumulus-oocyte complexes
Time frame: During the egg retrieval
number of cumulus-oocyte complexes (COCs) retrieved after each aspiration
4 secondary outcomes
Oocyte recovery rate
Time frame: day of the egg retrieval
Fertilization rate
Time frame: 1 day after the egg retrieval
Empty follicle rate
Time frame: day of the egg retrieval
Procedure time
Time frame: In seconds from needle insertion to its withdrawal for each ovary
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Apr 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing follicular flushing and follicular aspiration in people with Low Ovarian Reserve and Poor Response to Ovulation Induction Poseidon Type IV, run by Instituto Bernabeu at 1 site in Spain.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 14 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
number of cumulus-oocyte complexes (time frame: During the egg retrieval). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Apr 2026.