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.