Impact of IVF Hormonal Therapy on Endometrial Receptivity and Endometrial Senescent Cell Pathological Accumulation

Condition(s) studied

Investigational drug(s) / intervention(s)

Controlled Ovarian Stimulation + Luteal Phase Support: Short COS protocol with GnRH antagonist followed by progesterone supplementation. Will be initiated after a negative vaginal ultrasonographic scans to define ovarian quiescence, on days 1 and 2 of the menstrual period. For ovarian stimulation, 150-225 UI /day of FSHrec (GONAL F) will be administered along or in combination with 75 UI/day of HMG (Menopur). From day 6 onwards, HMG/FSHrec will be administered on an individual basis according to the serum E2 levels and transvaginal ovarian ultrasound scans and GnRH antagonist (Orgalutran) 0.25 mg /day is introduced as soon as a follicle of 14 mms diameter has achieved. hCGrec (6500 IU, Ovitrelle) will be administered when 7 or 8 follicles with a maximum diameter of \>17-18 mms will observed. 400 mg of micronized vaginal progesterone will be administered (200 mg twice a day vaginal route), during 5 days. An endometrial biopsy and a blood sample will be obtained 7 days after hCG administration (hCH+7)

Hormonal Replacement Therapy programmed artificial cycle: 6 mg of oestradiol orally administered starting the first day of the menstrual period, followed by an endometrial scan 10-days later, and when a 7 mms triple line endometrium has seen by vaginal ultrasound scan, 800 mg of micronized vaginal progesterone (400 mg twice a day vaginal route), during five days, will be added to the oestrogen therapy. An endometrial biopsy and a blood sample will be obtained on day 5 of progesterone administration (P+5)

Natural Cycle (NC): No hormonal stimulation. From day 6 of the menstrual period, follicular growth will be evaluated. As soon as a follicle reaches 17mm in diameter, ovulation test strips will be provided to assess LH levels in the first morning urine. The participant will report the positive and will be scheduled for sampling seven days later. An endometrial biopsy and a blood sample will be obtained 7 days after LH peak (LH+7)

Endometrial receptivity reference group: Recruited among women belonging to the oocyte donation program and will follow the procedures described above for the Natural Cycle group. No hormonal stimulation. From day 6 of the menstrual period, follicular growth will be evaluated. As soon as a follicle reaches 17mm in diameter, ovulation test strips will be provided to assess LH levels in the first morning urine. The participant will report the positive and will be scheduled for sampling seven days later. An endometrial biopsy and a blood sample will be obtained 7 days after LH peak (LH+7)

Study summary

Both controlled ovarian stimulation (COS) and frozen embryo transfer has become an integral part of in vitro fertilization (IVF) treatment. Fresh embryo transfer is usually performed by providing Luteal Phase Support (LPS) with progesterone after COS. Frozen embryo transfer (FET) is usually performed in artificial cycles with hormone replacement treatment (HRT), in which exogenous progesterone is administered, although it can also be performed in a Natural Cycle (without hormone supplementation) (NC). There is evidence that the supraphysiologic levels of estradiol and progesterone during COS+LPS and HRT could lead to morphologic and biochemical endometrial modifications, altering endometrial receptivity and lowering implantation and pregnancy rates.

We hypothesize that the supraphysiologic hormone levels required for both COS+LPS, and HRT may be inducing alterations in endometrial composition and function, specifically the chronic accumulation of senescent cells; either due to an excessive hormonal induction, a lack of clearance due to a deficit of uNKs, or a combination of both, ultimately affecting both endometrial receptivity and decidualization, worsening IVF outcomes.

The in vitro clearance of endometrial senescent cells by selective induction of apoptosis has been found to enhance the decidualization capacity of the rest of Endometrial Stromal Cells (EnSC), which could represent in a future adjuvant strategy to reduce the potentially deleterious effects of supraphysiologic hormone levels and improve reproductive outcomes in IVF patients.

The results derived from this project would have a direct impact on clinical practice. First, the results would allow us to evaluate, based on experimental data, potential endometrial side effects of stimulation protocols commonly used in IVF treatments. In addition, in the case of finding a pathological accumulation of senescent cells affecting endometrial receptivity, we will be able to in vitro evaluate the effectiveness of adjuvant senolytic (drugs designed to specifically remove senescent cells) compounds to in vitro improve the expression of endometrial receptivity markers, as a first step to demonstrate the effectiveness of their use in improving the reproductive outcomes of IVF patients.

Eligibility

Primary outcome measure(s)

• Endometrial receptivity — through study completion, an average of 2 years
  To evaluate in vitro (on cells) endometrial receptivity markers such as prolactin, Prolactin, IGFBP1, FOXO1, HOXA-10, CLU, SCAS5, DIO, VEGF, TGFβ, CD34, CD31, CD44, MMPs, IL-15, IL-11, IL-6, LIF, Glycodelin, β-catenin, ALCAM, IGF-1R, c-KIT, SMAD3, etc

Trial sites (1)

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