Assessing the Convenience of Natural Proliferative Phase Frozen Embryo Transfer

NCT06307184 | Recruiting

• 1 other identifier: 2301-LIS-007-AN
• Study Type: observational
• Target: 530
• Locations: 1 country
• Sites: 1

Brief Summary

This study will assess the convenience of the natural proliferative phase frozen embryo transfer (NPP-FET) in terms of number of number of appointments needed before cycle scheduling.

Conditions

Frozen Embryo Transfer

Keywords

Endometrial preparation; Natural cycle; Progesterone; Pregnancy

Outcome Measures

Primary Outcomes (1)

• Number of appointments needed before cycle scheduling

  Number of visits for cycle monitoring until embryo transfer scheduling

  Up to three weeks

Secondary Outcomes (6)

• Cycle duration until embryo transfer (days)

  Up to four weeks

• Proportion of patients with low progesterone values on the day of embryo transfer

  One day

• Human corionic gonadotropin (hCG) positive rate

  10-14 days after ET

• Miscarriage rate

  Up to 20 weeks after ET

• Ongoing pregnancy rate

  9-11 weeks after ET

Other Outcomes (2)

• Serum Relaxin-2 levels

  5 weeks

• Serum Luteinizing Hormone (LH) levels

  5 days

Study Arms (2)

Natural proliferative phase frozen embryo transfer (NPP-FET)

When the endometrial thickness is at least 7 mm, vaginal micronized progesterone will be initiated at 400mg every 12 hours, as per standard clinical practice, when the dominant follicle is at least 13 mm, serum estradiol (E2) levels are \>80 pg/ml, and serum progesterone levels are \<1.5ng/ml. One embryo will be transferred on the fifth day of progesterone supplementation under ultrasound guidance. Progesterone will be continued until the 11th week of pregnancy.

Procedure: Natural proliferative phase frozen embryo transfer

Natural cycle frozen embryo transfer (NC-FET)

When the mean dominant follicle diameter was at least 17 mm and the endometrial thickness was at least 7 mm, serum E2, progesterone and luteinizing hormone (LH) were evaluated. If a spontaneously LH peak was detected (E2\>80 pg/ml, LH peak \>18 mIU/mL with progesterone level \<1.5 ng/mL), vaginal micronized progesterone was started from the evening of ovulation at a dose of 200 mg every 12 hours. Conversely, whenever a LH peak was not detected (E2\>80 pg/ml, LH \<18mIU/ml and progesterone \<1,5 ng/ml), r-hCG 250µg (Ovitrelle®) was administered subcutaneously, followed, 48 hours later, by daily administration of 200 mg micronized vaginal progesterone every 12 hours. One embryo was transferred 7 days after r-hCG administration or 6 days after LH peak detection. Progesterone was continued until the 8th week of pregnancy.

Interventions

Natural proliferative phase frozen embryo transfer PROCEDURE

When endometrial thickness is above 7 mm, vaginal micronized progesterone will be administered 400mg 12/12h when the dominant follicle is at least 13 mm, serum estradiol (E2) levels are \>80 pg/ml, and serum progesterone levels are \<1.5ng/ml. Embryo transfer will be performed on the fifth day of progesterone.

Natural proliferative phase frozen embryo transfer (NPP-FET)

Eligibility Criteria

• Age: 18 Years - 49 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64)
• Sampling Method: Probability Sample

Study Population

The study group will include a prospectively recruited cohort of ovulatory patients undergoing their first or second FET attempt following oocyte donation in a natural proliferative phase protocol. The control group will include a retrospective cohort of ovulatory patients undergoing a natural cycle frozen embryo transfer following oocyte donation.

You may qualify if:

• Endometrial thickness ≥ 7 mm on the day of starting progesterone-based luteal phase support (LPS)
• Serum progesterone levels \<1.5 ng/ml on the day of starting progesterone-based LPS
• LPS with micronized progesterone 400mg b.i.d.
• Regular cycles (\>24 days, ≤ 38 days)
• IVF/ICSI with donated oocytes
• Single blastocyst stage embryo transfer
• First or second embryo transfer from the same cohort

You may not qualify if:

• Use of exogenous ovarian stimulation during FET
• Untreated hydrosalpinx, polyp, submucous myomas or severe adenomyosis
• Recurrent pregnancy loss (≥ 3 previous pregnancy losses)
• Recurrent implantation failure with embryos from oocyte donation (≥ 3 previous failed embryo transfers)
• Personalized initiation of exogenous progesterone according to a previous endometrial receptivity assay test

Sponsors & Collaborators

• Instituto Valenciano de Infertilidade de Lisboa: lead
• Gedeon Richter Ltd.: collaborator

Study Sites (1)

Instituto Valenciano de Infertilidade

Lisbon, Portugal

RECRUITING

Study Officials

• Ana R Neves, MP

  Instutito Valenciano de Infertilidade de Lisboa (IVI-RMA Lisboa)

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Ana R Neves, MD, PhD

CONTACT

218 503 210; ana.neves@ivirma.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: OTHER
• Sponsor Type: NETWORK
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 17, 2024
• First Posted: March 12, 2024
• Study Start: February 23, 2024
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: February 23, 2026

Record last verified: 2025-05

Locations

PT (1)