FET-LET-2x2: Tasas de Embarazo Clínico Después de la Transferencia de Embriones Congelados en Ciclos Naturales y Naturales Modificados (FET-LET-2x2)
FET-LET-2x2: Un Ensayo Aleatorizado Abierto de Factorial 2×2 que Compara las Tasas de Embarazo Clínico Después de la Transferencia de Embriones Congelados en Ciclos Naturales Verdaderos y Modificados Con y Sin Inhibidores de la Aromatasa
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:
- 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?
- 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.
Descripción general del estudio
Estado
Intervención / Tratamiento
Tipo de estudio
Inscripción (Estimado)
Fase
- No aplica
Contactos y Ubicaciones
Estudio Contacto
- Nombre: Jelena Vukovic, MD
- Número de teléfono: +381643070647
- Correo electrónico: jel.zor@gmail.com
Ubicaciones de estudio
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Novi Sad, Serbia, 21000
- Reclutamiento
- Specialized Gynecological Hospital "Ferona" Novi Sad
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Contacto:
- Stevan Milatović, Associate Professor
- Número de teléfono: +38121 3000220
- Correo electrónico: office@ferona.rs
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Criterios de participación
Criterio de elegibilidad
Edades elegibles para estudiar
Acepta Voluntarios Saludables
Géneros elegibles para el estudio
Descripción
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
Plan de estudios
¿Cómo está diseñado el estudio?
Detalles de diseño
- Propósito principal: Tratamiento
- Asignación: Aleatorizado
- Modelo Intervencionista: Asignación factorial
- Enmascaramiento: Ninguno (etiqueta abierta)
Armas e Intervenciones
Grupo de participantes/brazo |
Intervención / Tratamiento |
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Experimental: True Natural Cycle Without Letrozole
Participants undergo frozen embryo transfer in a true natural menstrual cycle without the use of either an aromatase inhibitor or ovulation trigger medication. Ovulation is monitored by ultrasound and serum hormone levels. Luteal phase support (vaginal progesterone 200 mg twice daily or subcutaneous progesterone 25 mg once daily) is initiated on the day of ultrasound-confirmed ovulation and continued until 12 weeks of gestation if pregnancy occurs. |
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. |
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Experimental: True Natural Cycle With Letrozole
Participants undergo frozen embryo transfer (FET) in a true natural menstrual cycle with administration of the aromatase inhibitor letrozole (2.5 mg twice daily) from cycle days 3-7. Ovulation is monitored by ultrasound and serum hormone levels. Luteal phase support (vaginal progesterone 200 mg twice daily or subcutaneous progesterone 25 mg once daily) is initiated on the day of ultrasound-confirmed ovulation and continued until 12 weeks of gestation if pregnancy occurs. |
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. Letrozole 2.5 mg administered orally twice daily from cycle days 3-7 during the early follicular phase. |
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Experimental: Modified Natural Cycle Without Letrozole
Participants undergo frozen embryo transfer in a modified natural menstrual cycle without the use of an aromatase inhibitor. When the dominant follicle reaches ≥17 mm and endometrial thickness is ≥7 mm, and after exclusion of a spontaneous LH surge by serum measurement, ovulation is triggered with recombinant human chorionic gonadotropin (hCG) 250 mcg. Luteal phase support (vaginal progesterone 200 mg twice daily or subcutaneous progesterone 25 mg once daily) is initiated 2 days after ovulation trigger and continued until 12 weeks of gestation if pregnancy occurs. |
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. Recombinant human chorionic gonadotropin (hCG) 250 mcg administered subcutaneously to trigger ovulation when follicular and endometrial criteria are met. |
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Experimental: Modified Natural Cycle With Letrozole
Participants undergo frozen embryo transfer (FET) in a modified natural menstrual cycle with administration of letrozole (2.5 mg twice daily) from cycle days 3-7. Ultrasound monitoring begins between cycle days 8-10. When the dominant follicle reaches ≥17 mm and endometrial thickness is ≥7 mm, and after exclusion of a spontaneous LH surge by serum LH measurement, ovulation is triggered with recombinant human chorionic gonadotropin (hCG) 250 mcg. Luteal phase support (vaginal progesterone 200 mg twice daily or subcutaneous progesterone 25 mg once daily) is initiated 2 days after ovulation trigger and continued until 12 weeks of gestation if pregnancy occurs. |
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. 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. |
¿Qué mide el estudio?
Medidas de resultado primarias
Medida de resultado |
Medida Descripción |
Periodo de tiempo |
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Clinical Pregnancy Rate
Periodo de tiempo: Approximately 4-6 weeks after embryo transfer.
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Number of pregnancies with an ultrasound-confirmed gestational sac per embryo transfer. |
Approximately 4-6 weeks after embryo transfer.
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Medidas de resultado secundarias
Medida de resultado |
Medida Descripción |
Periodo de tiempo |
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Biochemical Pregnancy Rate
Periodo de tiempo: Two weeks after embryo transfer.
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Number of pregnancies with elevated serum beta-human chorionic gonadotropin (β-hCG) levels measured two weeks after embryo transfer, per embryo transfer. |
Two weeks after embryo transfer.
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Implantation Rate
Periodo de tiempo: Approximately 4-6 weeks after embryo transfer.
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Number of ultrasound-confirmed gestational sacs divided by the number of embryos transferred. |
Approximately 4-6 weeks after embryo transfer.
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Miscarriage Rate
Periodo de tiempo: Up to 23 weeks of gestation.
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Pregnancy loss before 23 completed weeks of gestation, expressed per embryo transfer. |
Up to 23 weeks of gestation.
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Colaboradores e Investigadores
Patrocinador
Fechas de registro del estudio
Fechas importantes del estudio
Inicio del estudio (Actual)
Finalización primaria (Estimado)
Finalización del estudio (Estimado)
Fechas de registro del estudio
Enviado por primera vez
Primero enviado que cumplió con los criterios de control de calidad
Publicado por primera vez (Actual)
Actualizaciones de registros de estudio
Última actualización publicada (Actual)
Última actualización enviada que cumplió con los criterios de control de calidad
Última verificación
Más información
Términos relacionados con este estudio
Palabras clave
Términos MeSH relevantes adicionales
- Enfermedades urogenitales
- Enfermedades Genitales
- Enfermedades urogenitales femeninas
- Enfermedades urogenitales femeninas y complicaciones del embarazo
- Enfermedades Genitales Femeninas
- Esterilidad
- Infertilidad Femenina
- Efectos fisiológicos de las drogas
- Mecanismos moleculares de acción farmacológica.
- Hormonas
- Hormonas, sustitutos hormonales y antagonistas hormonales
- Inhibidores de enzimas
- Inhibidores de la síntesis de esteroides
- Antagonistas hormonales
- Antagonistas de estrógenos
- Hormonas peptídicas
- Péptidos
- Aminoácidos, péptidos y proteínas
- Proteínas
- Químicos orgánicos
- Compuestos heterocíclicos, 1 anillo
- Compuestos heterocíclicos
- Azoles
- Acciones farmacológicas
- Acciones y usos químicos
- Compuestos policíclicos
- Embarazos
- Esteroides
- Compuestos de anillo fusionado
- Nitrilos
- Hormonas esteroides gonadal
- Hormonas gonadales
- Embarazadas
- Embarazo
- Triazoles
- Gonadotropinas
- Hormonas placentarias
- Proteínas del embarazo
- Hormonas del cuerpo luteum
- Congéneres de progesterona
- Letrozol
- Inhibidores de la aromatasa
- Progesterona
- Gonadotropina coriónica
Otros números de identificación del estudio
- Ethics Approval No 01-39/8/1
Plan de datos de participantes individuales (IPD)
¿Planea compartir datos de participantes individuales (IPD)?
Información sobre medicamentos y dispositivos, documentos del estudio
Estudia un producto farmacéutico regulado por la FDA de EE. UU.
Estudia un producto de dispositivo regulado por la FDA de EE. UU.
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