Natural vs Programmed Frozen Embryo Transfer (NatPro)

Pre-eclampsia and other obstetric complications are elevated after IVF and Frozen Embryo Transfer (IVF-FET), although we do not know why. This clinical research study will compare pregnancy rates and patient experience with 2 commonly used frozen embryo transfer protocols and investigate the cause of pregnancy complications after IVF-FET.

What are the criteria to enroll in this study?

Please see below the criteria we are considering for this study.

• Women planning Frozen Embryo Transfer (FET), from embryos created with their own eggs
• Embryos frozen at the blastocyst stage (day 5-7)
• Age 18-41
• Regular menstrual cycles
• BMI (Body Mass Index) < 40
• Normal TSH and HgA1c

What factors would prevent you from participating?

You cannot enroll in the NatPro study if you check one or more of these boxes:

• Egg or embryo donation
• Gestational carrier
• Recurrent implantation failure
• Hydrosalpinx
• Contraindication to any of the study medications or pregnancy
• Anti-phospholipid syndrome

What does participation in this study involve?

• Participants will be randomly assigned to one of 2 FET protocols. Supplemented natural cycle (with hCG shot and vaginal progesterone) or programmed cycle (with oral estrogen and injectable progesterone).
• Participants can stay in the study for up to 3 embryo transfer attempts or until a successful pregnancy.
• Blood and urine samples will be collected prior to cycle start and in early pregnancy.
• When delivery occurs at Stanford hospital, participants are asked to donate their placenta to research.
• Financial compensation will be available for this study participants.