Frozen Embryo Transfer (FET), Infertility Female
Conditions
Keywords
Natural cycle FET
Brief summary
The goal of this clinical trial is to learn whether different natural approaches to preparing the uterus for frozen embryo transfer (FET) can improve pregnancy success in women undergoing in vitro fertilization (IVF) treatment. The main questions it aims to answer are: 1. Is a completely natural menstrual cycle more successful than a natural cycle in which ovulation is triggered with medication when preparing for frozen embryo transfer? 2. Does taking a medication called letrozole at the beginning of the cycle improve pregnancy success compared to not taking it? Researchers will compare four different approaches to see which one results in the highest chance of achieving a clinical pregnancy, confirmed by ultrasound. Participants will: * Be randomly assigned to one of four groups * Undergo monitoring with ultrasound and blood hormone tests during their menstrual cycle * In some groups, take letrozole tablets for a few days early in the cycle * In some groups, receive a hormone injection to help control the timing of ovulation * Undergo frozen embryo transfer at the appropriate time * Receive standard hormonal support after embryo transfer * Researchers will compare four different approaches to see which one results in the highest chance of achieving a clinical pregnancy, confirmed by ultrasound.
Interventions
Letrozole 2.5 mg administered orally twice daily from cycle days 3-7 during the early follicular phase.
Recombinant human chorionic gonadotropin (hCG) 250 mcg administered subcutaneously to trigger ovulation when follicular and endometrial criteria are met.
DRUGProgesterone
Luteal phase support with either vaginal progesterone 200 mg twice daily or subcutaneous progesterone 25 mg once daily, initiated after ovulation (or 2 days after hCG trigger) and continued until 12 weeks of gestation if pregnancy occurs.
Sponsors
University of Novi Sad
Study design
Allocation
RANDOMIZED
Intervention model
FACTORIAL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 40 Years
Healthy volunteers
No
Inclusion criteria
* Women aged 18 to 40 years * Regular menstrual cycles (26-35 days) * Scheduled for frozen embryo transfer (FET) in a natural menstrual cycle * Normal gynecological ultrasound findings without clinically significant uterine abnormalities * Ability to provide written informed consent
Exclusion criteria
* Use of preimplantation genetic testing (PGT) for the transferred embryo * Use of donor oocytes * Inadequate embryo survival after thawing, defined as loss of viability in more than 50% of blastomeres * Irregular menstrual cycles * Presence of clinically significant uterine abnormalities detected by ultrasound * Inability or unwillingness to provide written informed consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Clinical Pregnancy Rate | Approximately 4-6 weeks after embryo transfer. | Number of pregnancies with an ultrasound-confirmed gestational sac per embryo transfer. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Biochemical Pregnancy Rate | Two weeks after embryo transfer. | Number of pregnancies with elevated serum beta-human chorionic gonadotropin (β-hCG) levels measured two weeks after embryo transfer, per embryo transfer. |
| Implantation Rate | Approximately 4-6 weeks after embryo transfer. | Number of ultrasound-confirmed gestational sacs divided by the number of embryos transferred. |
| Miscarriage Rate | Up to 23 weeks of gestation. | Pregnancy loss before 23 completed weeks of gestation, expressed per embryo transfer. |
Countries
Serbia
Contacts
CONTACTJelena Vukovic, MD
Outcome results
None listed