Researchers in a 2026 study found that natural FETs using donor eggs were linked to higher live birth rates, lower miscarriage rates, and lower rates of some pregnancy complications compared to medicated FETs.
Natural FET
A 2026 meta-analysis explored ways to optimize natural FETs, examining ovulation timing, progesterone use, luteinized unruptured follicles, and cycle variability across natural, modified natural, and newer natural proliferative phase approaches.
A 2026 randomized trial found that natural FETs had similar healthy live birth rates to medicated FETs, but were linked to lower risks of preeclampsia, pregnancy loss, and some other pregnancy complications.
A 2025 randomized controlled trial found that natural cycle FETs led to higher live birth rates and fewer miscarriages than medicated FETs in ovulatory women with a good prognosis.
Researchers in a 2023 study found decreased adverse pregnancy and neonatal outcomes in those who performed a natural vs medicated FET, including abnormal birth weights, preeclampsia, preterm births, and more.
Researchers in a 2023 study share the results of a survey that evaluates the use and attitude of natural cycle FETs in US clinics, which some studies have recently shown can lead to improved pregnancy outcomes compared to medicated FETs.
Researchers in a 2022 study compared timing of euploid transfers and found that 160 h was optimal for modified natural FETs, while they found no optimal time for natural FETs.
The post discusses various frozen embryo transfer protocols, which includes a medicated FET, natural cycle FET (true natural/modified natural), and mild ovarian stimulated FET, along with their scheduling. In addition, it examines whether one FET protocol is superior to another, the relevance of the corpus luteum in medicated vs natural cycle FETs, and optimal progesterone levels.