Comparison of Pregnancy Rate (HCG+ Level) Obtained After a Replacement Embryonic in Spontaneous Cycle and Following Protocol "NPP". ComparisonNPPNCT06859944
Prospective Randomized Non-Inferiority Study Comparing Natural Cycle Frozen Embryo Transfer (NC-FET) to a New Type of Endometrial Preparation for FET: Natural Proliferative Phase (NPP-FET)
An observational study of Comparison of Pregnancy Rate (HCG+ Level) Obtained After a Replacement Embryonic in Spontaneous Cycle and Following Protocol "NPP". Comparison, run by Erasme University Hospital at 1 site in Belgium.
Trial summary
Frozen embryo replacement cycle :Two methods traditionally used: the spontaneous cycle and the artificial cycle.Now, Emergence of new protocols: NPP-FET or "Natural proliferative phase - frozen embryo transfer" Demonstrate non-inferiority between the NPP-FET and the spontaneous cycle, and superiority in terms of… Read more about this study
- Who is it for?
- Ages 18 to 45 years, women only
- Conditions the study is for
- Comparison of Pregnancy Rate (HCG+ Level) Obtained After a Replacement Embryonic in Spontaneous Cycle and Following Protocol "NPP". Comparison
- What is being tested?
- Embryo transfer
- How many people
- 272 participants
- Where
- 1 siteBelgium
- Study dates
- 5 Aug 2024to 30 Jun 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 18 to 45 years
- Women only
- No healthy volunteers
- Adult
Study population: Patients with regular cycles, candidates for replacement of embryos frozen in spontaneous cycle
Who may be able to join
- Single transfer Blastocyste
Who cannot join
- PGT (Preimplantation genetic diagnosis)
- Testicular Sperm
- Donor oocytes
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site, 1 recruiting
- Recruiting
Hopital Erasme
Brussels, 1070
Anne Delbaere
About this study
Frozen embryo replacement cycle :Two methods traditionally used: the spontaneous cycle and the artificial cycle.Now, Emergence of new protocols: NPP-FET or "Natural proliferative phase - frozen embryo transfer" Demonstrate non-inferiority between the NPP-FET and the spontaneous cycle, and superiority in terms of planning.
Read the detailed description
The protocol Natural proliferative phase/Natural Programmed by Progesterone, Patients with regular cycles, candidates for replacement of embryos frozen in a spontaneous cycle. The monitoring of the cycle is carried out by taking blood and follicular ultrasound between the 10th and 13th day of the cycle. Support luteal phase by intravaginal progesterone (utrogestan 200 mg) 1 tablet, 2 times per day, is initiated once the following criteria are met:
- Thickness of the endometrium > 7 mm on ultrasound
- Ovarian follicle > 14 mm
- Estradiol( E2) > 120 pg/mL Embryo transfer is scheduled on the 6th day of progesterone exposure exogenous. A progesterone dosage on the day of transfer will be systematically realized
- Being tested
- Embryo transfer
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Embryo transferOther
Frozen embryo transfer
Embryo transferOther
Frozen Embryo transfer
| Study group | Role | What they receive |
|---|---|---|
| single transfer of frozen blastocyst in natural cycle | Not described Receives: Other: Embryo transfer | |
| Natural Cycle Programmed by Progesterone | Not described Receives: Other: Embryo transfer |
What is being measured
The primary outcome is the main question the study is designed to answer.
Comparison of the pregnancy rate (Human chorionic gonadotropin hormone) (HCG+ level) obtained after spontaneous embryo replacement and following the "NPP" protocol.
Measured: Thrugh study completion (9 months)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Mar 2025
- Study start5 Aug 2024
- Primary completion30 Jun 2025 (estimated)
- Study completion30 Jun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Comparison of Pregnancy Rate (HCG+ Level) Obtained After a Replacement Embryonic in Spontaneous Cycle and Following Protocol "NPP". ComparisonStudies 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
- Observational
- Observational model
- Other
- Time perspective
- Prospective
- Enrolment
- 272 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Erasme University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Anne Delbaere, Erasme University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06859944
- Sponsor's protocol ID
- SRB2024108
- Acronym
- NPP
- Status last verified
- Mar 2025
- First submitted
- 27 Feb 2025
- Last updated
- 10 Mar 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Mar 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prospective Randomized Non-Inferiority Study Comparing Natural Cycle Frozen Embryo Transfer (NC-FET) to a New Type of Endometrial Preparation for FET: Natural Proliferative Phase (NPP-FET)
- ClinicalTrials.gov ID
- NCT06859944
- Acronym / sponsor ID
- NPP / SRB2024108
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 272 participants (estimated)
- Lead sponsor
- Erasme University HospitalUniversity, hospital or other
- Study start
- 5 Aug 2024 (actual)
- Primary completion
- 30 Jun 2025 (estimated)
- Study completion
- 30 Jun 2026 (estimated)
- First posted
- 5 Mar 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.
Frozen embryo replacement cycle :Two methods traditionally used: the spontaneous cycle and the artificial cycle.Now, Emergence of new protocols: NPP-FET or "Natural proliferative phase - frozen embryo transfer" Demonstrate non-inferiority between the NPP-FET and the spontaneous cycle, and superiority in terms of planning.
Detailed description
The protocol Natural proliferative phase/Natural Programmed by Progesterone, Patients with regular cycles, candidates for replacement of embryos frozen in a spontaneous cycle. The monitoring of the cycle is carried out by taking blood and follicular ultrasound between the 10th and 13th day of the cycle. Support luteal phase by intravaginal progesterone (utrogestan 200 mg) 1 tablet, 2 times per day, is initiated once the following criteria are met:
- Thickness of the endometrium > 7 mm on ultrasound
- Ovarian follicle > 14 mm
- Estradiol( E2) > 120 pg/mL Embryo transfer is scheduled on the 6th day of progesterone exposure exogenous. A progesterone dosage on the day of transfer will be systematically realized
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| single transfer of frozen blastocyst in natural cycle | – | Other: Embryo transfer |
| Natural Cycle Programmed by Progesterone | – | Other: Embryo transfer |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- Patients with regular cycles, candidates for replacement of embryos frozen in spontaneous cycle
Key inclusion criteria (1 listed)
- Single transfer Blastocyste
Key exclusion criteria (3 listed)
- PGT (Preimplantation genetic diagnosis)
- Testicular Sperm
- Donor oocytes
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 |
|---|---|---|
| Embryo transferFrozen embryo transfer | Other | Natural Cycle Programmed by Progesterone |
| Embryo transferFrozen Embryo transfer | Other | single transfer of frozen blastocyst in natural cycle |
Primary outcome
Comparison of the pregnancy rate (Human chorionic gonadotropin hormone) (HCG+ level) obtained after spontaneous embryo replacement and following the "NPP" protocol.
Time frame: Thrugh study completion (9 months)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Mar 2025.
- Individual participant dataSharing planned: No
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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Comparison of Pregnancy Rate (HCG+ Level) Obtained After a Replacement Embryonic in Spontaneous Cycle and Following Protocol "NPP". Comparison, run by Erasme University Hospital at 1 site in Belgium.
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 1 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: looking for participants now, as of the sponsor's last update on 10 Mar 2025. 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 Belgium. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Anne Delbaere (+32 2 555 45 70, anne.delbaere@hubruxelles.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Comparison of the pregnancy rate (Human chorionic gonadotropin hormone) (HCG+ level) obtained after spontaneous embryo replacement and following the "NPP" protocol. (time frame: Thrugh study completion (9 months)). 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 10 Mar 2025.