What Is the Difference Between a Natural-Cycle Frozen Embryo Transfer (FET) and a Medicated FET?

There are two possible options for performing a frozen embryo transfer (FET): Natural-Cycle FET (NC-FET) and medicated FET. The professionals at Dominion Fertility are here to provide some insight on these options and the differences between NC-FET and medicated FET.

Natural-Cycle FET (NC-FET)

Natural Cycle FET is an option for women with regular ovulation and monthly menstrual cycles. In patients with predictable menstrual cycles, doctors can carefully monitor the cycle to determine the precise timing of ovulation. Alternatively, ovulation can be induced with the administration of an HCG injection. Once the precise date of ovulation is set, then the uterine lining should be receptive to embryo transfer 5 days later (for embryos frozen on day 5 in a previous IVF cycle). In this way, the embryos can be replaced at approximately the time when they would normally be arriving in the uterus.

Benefits and Challenges of Natural-Cycle FET

The primary benefit of Natural-Cycle FET is its minimal additional medications. However, this comes at the cost of several additional challenges and setbacks for patients:

• Unlike medicated FET, Natural-Cycle FET offers less control—allowing for very little planning or scheduling. The optimal time for implantation may fall at a challenging time for patient and laboratory schedules. As such, it can be impossible to guarantee patients that they will have access to the most optimal transfer window.
• NC-FET demands frequent patient monitoring around the time of ovulation. If a cycle is suboptimal in terms of the estrogen level and endometrial development, then the embryos will not be thawed and the cycle will be canceled.
• While the advantage of fewer medications is often associated with cost savings for Natural-Cycle FET, it can take 3-4 attempts to achieve the same results as a medicated FET. In these cases, patients can often pay much more for a Natural-Cycle FET pregnancy.

Dominion Fertility strives to support the most successful possible treatment options for our patients. As such, we only offer medicated FET services at this time.

Medicated FET IVF Treatment

A medicated FET allows the couple to avoid some of the pitfalls associated with an NC-FET. In this type of FET, estrogen pills, shots, or patches are used to prepare the endometrium for embryo implantation. Three days prior to embryo transfer, the woman begins taking progesterone to modify the endometrial lining so that it will be receptive when the embryos are placed. Some clinics prescribe GnRH agonists (such as Lupron) to their patients the month prior to a medicated FET cycle so as to reduce the chances of spontaneous ovulation. The use of Lupron reduces the chances of cycle cancellation owing to unexpected ovulation to near zero.

The choice of estrogen supplementation varies somewhat between clinics. Some clinics prescribe oral estrogens; other clinics administer intramuscular estrogen shots twice a week, and still other clinics use transdermal estrogen patches twice a week. The choice of estrogen protocol is clinic-specific and should be discussed with your reproductive endocrinologist. Many clinics prescribe progesterone-in-oil injections to prepare the lining for embryo transfer. Women who have a progesterone allergy can use progesterone suppositories instead.

IVF Overview: Natural-Cycle vs Medicated FETs

Pregnancy rates have not been shown to differ significantly between NC-FET and medicated FET. However, medicated FETs do help patients circumvent the setbacks of Natural-Cycle FETs listed above. The advantages of NC-FET are its simplicity with no injections (besides the HCG trigger shot) and minimal additional medications.

Dominion Fertility: Medicated FET IVF Treatments

Dominion Fertility has been a nationwide leader in making IVF treatments safe, affordable, and successful. To learn more about frozen embryo transfers, head over to the FET category of our fertility blog. Patients travel from all over to receive medicated FET treatments at our fertility center in Arlington, Virginia. We invite you to contact our professionals or make an appointment to get started today!