Efficacy of Oral Micronized Progesterone versus Vaginal Progesterone Gel for Luteal Phase Support in Frozen Embryo Transfer Cycles

International Journal of Obstetrics and Gynecology | Vol. 14, No. 8, August 2026 | pp. 301–312

DOI: 10.46882/2026/IJOG/000502

Original Research Article

Title: Efficacy of Oral Micronized Progesterone versus Vaginal Progesterone Gel for Luteal Phase Support in Frozen Embryo Transfer Cycles

Names of Authors: Anita P. Nwosu¹, Samuel T. Kudoyin²

Authors’ Affiliations:
¹ Reproductive Endocrinology and Infertility Unit, Department of Obstetrics and Gynecology, Lagos State University Teaching Hospital, Ikeja, Nigeria
² Department of Radiology, College of Medicine, University of Lagos, Lagos, Nigeria

Abstract:
Luteal Phase Support (LPS) is crucial for optimizing endometrial receptivity during artificial frozen embryo transfer (FET) cycles. This prospective, randomized, open-label trial evaluated the clinical efficacy, safety, and patient compliance of oral micronized progesterone (combined with oral dydrogesterone) versus standard vaginal progesterone gel for LPS. A cohort of 320 infertile women undergoing programmed FET cycles with high-grade blastocysts was randomized into two equal groups (n = 160 per group). The oral group received 400 mg oral micronized progesterone daily combined with 10 mg dydrogesterone three times daily. The vaginal group received 90 mg vaginal progesterone gel 8% once daily. Both regimens were initiated on the day of endometrial transformation and continued until 10 weeks of gestation if pregnancy occurred. The primary endpoint was the ongoing pregnancy rate at 12 weeks. Results demonstrated that the ongoing pregnancy rate was statistically comparable between the oral and vaginal groups (46.3% vs. 44.4%; Relative Risk [RR] = 1.04; 95% Confidence Interval [CI], 0.82 to 1.32; p = 0.74). The live birth rates were also similar between the arms (38.8% vs. 36.9%, p = 0.73). However, patient satisfaction and compliance scores were significantly higher in the oral cohort due to the absence of local vaginal irritation and discharge (92.5% vs. 71.3%, p < 0.001). In conclusion, combined oral progesterone administration provides excellent clinical pregnancy outcomes equivalent to vaginal gel routines, offering a well-tolerated and preferred alternative for patients undergoing frozen embryo transfer.

Keywords: Luteal Phase Support; Frozen Embryo Transfer; Micronized Progesterone; Vaginal Gel; Ongoing Pregnancy Rate; Patient Compliance.

Manuscript Timeline: Received: May 11, 2026; Revised: July 02, 2026; Accepted: July 25, 2026; Published: August 03, 2026.

Citation: Nwosu AP, Kudoyin ST. Efficacy of Oral Micronized Progesterone versus Vaginal Progesterone Gel for Luteal Phase Support in Frozen Embryo Transfer Cycles. International Journal of Obstetrics and Gynecology. 2026; 14(8): 301–312.

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