In modified natural cycles for frozen embryo transfer (FET), one area of focus has been the size of the dominant follicle just before starting progesterone, the hormone that prepares the uterus for implantation. A recent study conducted by Austin Fertility & Reproductive Medicine/Westlake IVF explored whether the size of the lead follicle prior to beginning luteal phase progesterone had any effect on important clinical outcomes like implantation, pregnancy, miscarriage, or live birth. The results revealed that there were no significant differences in these outcomes based on follicle size.
Dr. Shahryar Kavoussi said, “The results revealed that there were no significant differences in these outcomes based on follicle size.” This means that as long as the endometrial thickness meets criteria and progesterone levels are at pre-ovulatory levels, we can proceed with luteal progesterone supplementation and plan embryo transfer accordingly regardless of lead follicle size, which can minimize the number of monitoring ultrasound visits during such cycles.”
What does this mean for patients? It could lead to fewer monitoring appointments and a more streamlined approach to frozen embryo transfer, without compromising success. As always, individual protocols are tailored to each patient’s specific needs and should be discussed.
Read the full study: Impact of follicle size before luteal progesterone supplementation on clinical outcomes of modified natural cycle single frozen embryo transfer
