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IVFPhase 4PRO_NATNCT05954962

Efficacy of Micronized Natural Progesterone vs GnRH Antagonist in the Prevention of LH Peak During Ovarian Stimulation.

A Phase 4 study testing Progesterone 200 MG and Ganirelix Acetate in people with IVF, run by Instituto Bernabeu at 1 site in Spain.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This study aims to investigate if the use of oral micronized natural progesterone is not inferior to the use of subcutaneous antagonist in preventing LH peak in controlled ovarian stimulation. Read more about this study

Who is it for?
Ages 18 to 33 years, women onlyHealthy volunteers can take part
Conditions the study is for
IVF
What is being tested?
Progesterone 200 MG and Ganirelix Acetate
Could I receive a placebo?
No, everyone receives an active treatment
How many people
150 participants
Where
1 siteSpain
Study dates
23 Dec 2023to 30 Aug 2025
Phase
Phase 4
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 18 to 33 years
  • Women only
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Eligibility for the oocyte donation program at Instituto Bernabeu.
  • Age between 18 and 33 years
  • BMI >18 and <30
  • Overall antral follicle count >8
  • Presence of both ovaries
  • Ability to participate and comply with the study protocol
  • Oral and written comprehension of Spanish
  • Having given written consent

Who cannot join

  • Endometriosis at any stage
  • Any ovarian tumor whether benign or malignant
  • Concurrent participation in another study
  • Malabsorptive syndromes that may alter the efficacy of Seidigestan ® such as bariatric surgery, ulcerative colitis or Crohn's disease
  • Irregular periods
  • Hypogonadotropic hypogonadism
  • Having received in the previous two months treatment with ovulation stimulators
  • Having previously participated in the present study

Trial locations and contacts

1 site in 1 country.

Spain1 site

  • Instituto Bernabeu

    Elche, Alicante, 03206

Other trials in Spain

About this study

Official title: Evaluation of the Efficacy of Micronized Natural Progesterone (Seidigestan®) vs GnRH Antagonist (Astarté®) in the Prevention of LH Peak During Controlled Ovarian Stimulation: a Randomized Clinical Trial.

This study aims to investigate if the use of oral micronized natural progesterone is not inferior to the use of subcutaneous antagonist in preventing LH peak in controlled ovarian stimulation.

Read the detailed description

The study will aim to include 150 women (egg donors): 75 per group and the principal variable will be the number of retrieved mature (MII) oocytes. Randomized, prospective, controlled, single center, phase IV study.

Conditions
IVF
Being tested
Progesterone 200 MG, Ganirelix Acetate

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Progesterone 200 MGDrug

    The patients in the study group will administer oral natural micronized progesterone capsules from day 1 of ovarian stimulation instead of "antagonist" (ganirelix) subcutaneaous injections from day 5-6 of stimulation.

  • Ganirelix AcetateDrug

    The patients in the control group will administer subcutaneaous injections of ganirelix from day 5-6 of stimulation as per currently used protocol.

Study groups in NCT05954962
Study groupRoleWhat they receive
CONTROL GROUPActive comparatorThe patient will start to administer: (1) daily subcutaneous injections of gonadotropins on day 1 of ovarian stimulation (2) daily subcutenous injections of ganirelix ("antagonist") on day 5 or 6 of ovarian stimulation. Both medication will be stopped 1-2 days before egg retrieval.
Receives: Drug: Ganirelix Acetate
STUDY GROUPExperimentalThe patient will start to administer: (1) daily subcutaneous injections of gonadotropins on day 1 of ovarian stimulation (2) daily oral capsules of natural micronized progesterone on day 1 of ovarian stimulation. Both medication will be stopped 1-2 days before egg retrieval.
Receives: Drug: Progesterone 200 MG

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. MII oocytes

    number of mature (MII) oocytes in both stimulations.

    Measured: Egg collection day (between 8 and 14 days after starting of ovarian stimulation)

Secondary outcomes (1)

  1. Duration

    duration of ovarian stimulation under both protocols.

    Measured: Egg collection day (between 8 and 14 days after starting of ovarian stimulation)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted20 Jul 2023
  2. Study start23 Dec 2023
  3. Primary completion3 Apr 2025
  4. Study completion30 Aug 2025

Resources

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 4
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
150 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05954962
Sponsor's protocol ID
IBMR43
Acronym
PRO_NAT
Status last verified
Nov 2024
First submitted
12 Jul 2023
Last updated
27 Mar 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: The information collected in the study will always be treated as grouped data and never as individual or personal data, thus maintaining anonymity and confidentiality.

Publications

  • A double-blind, randomized, dose-finding study to assess the efficacy of the gonadotrophin-releasing hormone antagonist ganirelix (Org 37462) to prevent premature luteinizing hormone surges in women undergoing ovarian stimulation with recombinant follicle stimulating hormone (Puregon). The ganirelix dose-finding study group. Hum Reprod. 1998 Nov;13(11):3023-31.

    PubMed 9853849

  • Balasch J, Creus M, Fabregues F, Carmona F, Casamitjana R, Penarrubia J, Rivera F, Vanrell JA. Hormonal profiles in successful and unsuccessful implantation in IVF-ET after combined GnRH agonist/gonadotropin treatment for superovulation and hCG luteal support. Gynecol Endocrinol. 1995 Mar;9(1):51-8. doi: 10.3109/09513599509160191.

    PubMed 7793300

  • Begueria R, Garcia D, Vassena R, Rodriguez A. Medroxyprogesterone acetate versus ganirelix in oocyte donation: a randomized controlled trial. Hum Reprod. 2019 May 1;34(5):872-880. doi: 10.1093/humrep/dez034.

    PubMed 30927417

  • Castillo JC, Haahr T, Martinez-Moya M, Humaidan P. Gonadotropin-releasing hormone agonist for ovulation trigger - OHSS prevention and use of modified luteal phase support for fresh embryo transfer. Ups J Med Sci. 2020 May;125(2):131-137. doi: 10.1080/03009734.2020.1736696. Epub 2020 May 4.

    PubMed 32366146

  • Fauser BC, Devroey P. Why is the clinical acceptance of gonadotropin-releasing hormone antagonist cotreatment during ovarian hyperstimulation for in vitro fertilization so slow? Fertil Steril. 2005 Jun;83(6):1607-11. doi: 10.1016/j.fertnstert.2005.02.011.

    PubMed 15950626

  • Giles J, Alama P, Gamiz P, Vidal C, Badia P, Pellicer A, Bosch E. Medroxyprogesterone acetate is a useful alternative to a gonadotropin-releasing hormone antagonist in oocyte donation: a randomized, controlled trial. Fertil Steril. 2021 Aug;116(2):404-412. doi: 10.1016/j.fertnstert.2021.02.036. Epub 2021 Apr 2.

    PubMed 33814126

  • Griesinger G, Dawson A, Schultze-Mosgau A, Finas D, Diedrich K, Felberbaum R. Assessment of luteinizing hormone level in the gonadotropin-releasing hormone antagonist protocol. Fertil Steril. 2006 Mar;85(3):791-3. doi: 10.1016/j.fertnstert.2005.08.048.

    PubMed 16500366

  • Guo YC, Chen PY, Li TT, Jia L, Sun P, Zhu WS, Deng CC, Fang C, Liang XY. Different progestin-primed ovarian stimulation protocols in infertile women undergoing in vitro fertilization/intracytoplasmic sperm injection: an analysis of 1188 cycles. Arch Gynecol Obstet. 2019 Apr;299(4):1201-1212. doi: 10.1007/s00404-019-05065-4. Epub 2019 Mar 9.

    PubMed 30852654

  • Kuang Y, Chen Q, Fu Y, Wang Y, Hong Q, Lyu Q, Ai A, Shoham Z. Medroxyprogesterone acetate is an effective oral alternative for preventing premature luteinizing hormone surges in women undergoing controlled ovarian hyperstimulation for in vitro fertilization. Fertil Steril. 2015 Jul;104(1):62-70.e3. doi: 10.1016/j.fertnstert.2015.03.022. Epub 2015 May 5.

    PubMed 25956370

  • Macklon NS, Stouffer RL, Giudice LC, Fauser BC. The science behind 25 years of ovarian stimulation for in vitro fertilization. Endocr Rev. 2006 Apr;27(2):170-207. doi: 10.1210/er.2005-0015. Epub 2006 Jan 24.

    PubMed 16434510

  • Messinis IE, Templeton AA. Endocrine and follicle characteristics of cycles with and without endogenous luteinizing hormone surges during superovulation induction with pulsatile follicle-stimulating hormone. Hum Reprod. 1987 Jan;2(1):11-6. doi: 10.1093/oxfordjournals.humrep.a136481.

    PubMed 3106404

  • Porter RN, Smith W, Craft IL, Abdulwahid NA, Jacobs HS. Induction of ovulation for in-vitro fertilisation using buserelin and gonadotropins. Lancet. 1984 Dec 1;2(8414):1284-5. doi: 10.1016/s0140-6736(84)92840-x. No abstract available.

    PubMed 6150318

  • Yu S, Long H, Chang HY, Liu Y, Gao H, Zhu J, Quan X, Lyu Q, Kuang Y, Ai A. New application of dydrogesterone as a part of a progestin-primed ovarian stimulation protocol for IVF: a randomized controlled trial including 516 first IVF/ICSI cycles. Hum Reprod. 2018 Feb 1;33(2):229-237. doi: 10.1093/humrep/dex367.

    PubMed 29300975

  • Zhu X, Ye H, Fu Y. Duphaston and human menopausal gonadotropin protocol in normally ovulatory women undergoing controlled ovarian hyperstimulation during in vitro fertilization/intracytoplasmic sperm injection treatments in combination with embryo cryopreservation. Fertil Steril. 2017 Sep;108(3):505-512.e2. doi: 10.1016/j.fertnstert.2017.06.017. Epub 2017 Jul 8.

    PubMed 28697910

  • Martinez-Moya M, Guerrero J, Girela JL, Pitas A, Bernabeu A, Bernabeu R, Castillo JC. Micronized natural progesterone (Seidigestan(R)) vs GnRH antagonists for preventing the LH surge during controlled ovarian stimulation (PRO_NAT study): study protocol of a randomized clinical trial. Front Endocrinol (Lausanne). 2024 Mar 21;15:1350154. doi: 10.3389/fendo.2024.1350154. eCollection 2024.

    PubMed 38577571

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Progesterone 200 MG and Ganirelix Acetate in people with IVF, 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 8 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 27 Mar 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.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

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?

MII oocytes (time frame: Egg collection day (between 8 and 14 days after starting of ovarian stimulation)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05954962, which also lists 15 linked publications.

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 27 Mar 2026.

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