NCT06053827

Natural Frozen Embryo Transfer (FET) vs Substituted Frozen Embryo Transfer (FET)

Embryo Transfer in Natural vs Substituted Cycle and the Scheduling Pattern of IVF

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 1,207 (actual)
• Sponsor: Clinique Ovo · Industry
• Sex: Female
• Age: 40 Years
• Healthy volunteers: —

Summary

In frozen embryo transfer substituted cycles, patients are treated with progesterone and estrogen in an attempt to mimic the natural cycle and a transfer is planned whenever the endometrium is ready. In contrast, in frozen embryo transfer natural cycle patients are not taking any hormones, only triggered with hCG (human chorionic gonadotropin) when a dominant follicle is ready or they wait for the disappearance of the dominant follicle to plan the transfer date. Some doctors and centres shift towards using the substituted protocol in an attempt to make scheduling easier with less frequent ultrasounds. This study will aim to compare clinical and biochemical pregnancy rates in patients who underwent frozen embryo transfers in natural cycles vs substituted cycles at the centre.

Conditions

• Fertility Disorders

Interventions

Type	Name	Description
OTHER	Frozen embryo transfer	A frozen embryo transfer involves thawing a fertilized embryo and transferring it in the uterus in order to obtain a pregnancy

Timeline

• Start date: 2023-09-19
• Primary completion: 2023-11-30
• Completion: 2024-07-18
• First posted: 2023-09-26
• Last updated: 2025-12-09

Locations

1 site across 1 country: Canada