Related Experiment Video
Updated: May 17, 2026
Methods for Studying Uterine Contributions to Pregnancy Establishment in an Ovariectomized Mouse Model
Published on: April 7, 2023
Endometrin as luteal phase support in assisted reproduction
Eve C Feinberg1, Angeline N Beltsos1, Elitsa Nicolaou2
1Fertility Centers of Illinois, Chicago, Illinois.
Objective:
To compare clinical pregnancy rate (PR) and live birth rate (LBR) between Endometrin monotherapy versus Endometrin and P in oil combination therapy in assisted reproductive technology (ART) cycles.
Design:
Retrospective analysis.
Setting:
Large private practice.
Patient(S):
Patients undergoing autologous fresh IVF cycles, autologous frozen ET cycles, and fresh oocyte donor cycles were included for analysis.
Intervention(S):
Endometrin as a single agent for luteal support, Endometrin monotherapy or Endometrin with P in oil used at least once every 3 days for luteal support, Endometrin combination therapy.
Main Outcome Measure(S):
Clinical PR and LBR.
Result(S):
A total of 1,034 ART cycles were analyzed. Endometrin monotherapy was used in 694 of 1,034 (67%) cycles and Endometrin combination therapy was used in 340 of 1,034 (33%) cycles. In all fresh cycles, clinical PR was not significantly different (IVF autologous: Endometrin monotherapy 46.9% vs. Endometrin combination therapy 55.6%; donor oocyte endometrin monotherapy 45.2% vs. Endometrin combination therapy 52.0%). Frozen ET cycles had a significantly higher clinical PR and LBR with combination therapy group compared with monotherapy (clinical PR 47.9% vs. 23.5%; LBR 37.5% vs. 17.3%).
Conclusion(S):
Endometrin monotherapy was sufficient for the P component of luteal support and provided high PRs for fresh cycles in both autologous and donor oocyte cycles. Clinical PR and LBR in frozen ET cycles were significantly improved with the addition of IM P to Endometrin therapy. This may reflect the fact that lesser quality embryos are transferred in frozen ET cycles, and more intense P support is required for comparable PRs.
More Related Videos
Related Concept Videos
01:27Ovarian Cycle
01:20Proliferative Phase
Notably, the stratum basale, the basal layer of the endometrium, including the basal parts of the uterine glands, remains unaffected by menstruation. Stem cells in this layer undergo mitosis, regenerating the stratum functionalis and thickening the...
01:19Secretory Phase
Following ovulation, the corpus luteum, a temporary endocrine structure, produces progesterone and estrogens. These hormones stimulate the growth and coiling of endometrial...
01:22Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
01:19The Menstrual Cycle
The menstrual phase occurs from days 1 to 5 and involves the shedding of the stratum functionalis, as a uterine...
01:30Hormonal Control of the Ovarian Cycle
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...