P-536 The comparison of luteal phase support in modified natural cycle-frozen embryo transfer in young patients with high quality embryos -vaginal versus vaginal and subcutaneous progesterone.
Authors: Bakir V L , Ozer G , Akca A , Balin Duzguner I N , Kahraman S 
Published: June 2023

Study question

Does adding subcutaneous progesterone to vaginal administration affect pregnancy outcomes in young patients undergoing modified natural-frozen embryo transfer (mNC-FTET) with top-good quality, single blastocyst ?

Summary answer

Adding subcutaneous progesterone supplementation to vaginal administration after frozen-thawed embryo transfer in modified natural cycles does not improve live birth rates.

What is known already

Vaginal progesterone supplementation during frozen-thawed embryo transfer in modified natural cycles during luteal phase may increase the rate of live birth rate and decrease the rate of miscarriage.

Study design, size, duration

245 participants were included in this retrospective cohort study conducted at a single IVF center between November 2020and January 2022.The primary outcome was the live birth rate; secondary outcomes included pregnancy, clinical pregnancy and biochemical and clinical abortion rates.

Participants/materials, setting, methods

245 women aged 20-35 years in mNC-FTET cycles with a single top-good quality blastocyst embryo transfer were included. Patients with fibroids, synechiae, recurrent implantation failure, recurrent pregnancy loss were excluded. After thawing embryos were evaluated for quality, hCG(Ovitrelle-Merck) triggered; 129 patients received 200 mg vaginal progesterone (Lutinus-Merck)(group I), while 116 received 200 mg. vaginal and 25 mg subcutaneous progesterone (Progestan-Dex-Kocak Pharma) (group II). The main outcome was live birth rate(LBR), secondary outcome was miscarriage rate.

Main results and the role of chance

Baseline demographics and background characteristics were similar in the study groups. The live birth rate in group I is 86 of 106 (66.6%) compared 74 of 116 (63.7%) in group II (odds ratio 1,135, 95% confidence interval [CI]: 0.670-0.922, P = 0.637). There were 106 pregnant patients out of 129 in group I (82.17%) and 93 pregnant patients out of 116 in group II (odds ratio 0.877, 95 CI: 0.462-1,666, P = 0.68). The clinical pregnancy rate is 95 out of 129 patients (73.6%) in group I and 90 out of 116 patients in group II (odds ratio of 0.807, 95% confidence interval [CI]: 0.449-1.45, P = 0.474). The rate of biochemical abortion in group II was 10 of 129 patients (7.75%) and 4 of 116 (3.45%) (odds ratio 2.35, 95 CI: 0.717–7.718, P = 0.687). The clinical abortion rate was 6 of 129 patients (4.6%) and 6 of 116 patients (5.17%) in group II (odds ratio 2.35, 95 CI: 0.717-7.718; P = 0.687). According to primary and secondary outcomes, there were no significant differences between the groups.

Limitations, reasons for caution

To avoid bias, patients older than 35 years were excluded. Subcutaneous progesterone may be beneficial for older patients undergoing euploid embryo transfer. To reduce confounding factors, the number of patients was limited.

Wider implications of the findings

For luteal phase support, both vaginal and subcutaneous progesterone supplementation did not increase live birth rates following frozen-thawed embryo transfer in modified natural cycles in young patients.

Trial registration number

not applicable