Impact of Serum Progesterone in Modified Natural Cycles and Stimulated Cycles on Ongoing Pregnancy Rate
Condition: Infertility, Female
MeSH terms: Infertility; Infertility, Female
Study type: Observational [Patient Registry]

Summary: 
      Prospective cohort unicentric study including infertile patients undergoing an embryo
      transfer in the context of natural or stimulated cycles and receiving luteal phase support
      with vaginal natural progesterone following the clinical practice in our clinic in IVIRMA
      Valencia, Spain.
    

Detailed description: 
      Progesterone as a promoter of endometrial maturation is essential for the process of embryo
      implantation. The transformation of the endometrium from a proliferative state to a receptive
      state depends on the adequate progesterone exposure of the endometrium. Therefore, in any
      assisted reproduction technique (ART) the management of the luteal phase with exogenous
      administered progesterone, aiming to achieve a receptive endometrial state, is an essential
      part of the therapy. This important part of infertility-treatment is called luteal phase
      support (LPS).

      Currently, there is a scientific debate and research regarding the timing, the dose and route
      of administration of exogenous progesterone in ART cycles. For years, the administration of
      progesterone was based on a "one fits all"- concept, mainly driven from the doctors and
      patients' preference regarding dose, timing and route of administration of the exogenous
      progesterone. Due to the lack of solid and evidence-based knowledge, the LPS improving
      investigating LPS is of outmost importance.

      Therefore, improving the LPS is continuously in the focus of research and investigation. Main
      objectives of those efforts are to clarify the optimal timing, dosage and route of
      administration of progesterone for every possible ART procedure, in order to improve therapy
      outcomes. Of special interest in this wide field is the management of LPS in
      embryo-transfer-cycles such as substituted cycles and modified natural cycles for
      frozen-thawed cycles, and in fresh embryo-transfers after stimulated cycles.

      Measuring serum progesterone levels in the luteal phase of a transfer cycle seems to be a
      promising approach in resolving the former mentioned doubts. Now, research focuses on
      luteal-phase serum progesterone levels as a predictor of outcomes. The discovery of certain
      thresholds of progesterone levels in the serum would give us a handy tool for individualizing
      the LPS with the main objective to improve outcomes.

      Previous studies could show that there exist certain thresholds of serum progesterone in
      substituted cycles that could be used as a predictor. Furthermore, the same group could show
      that modifying the dose and the route of administration in the sense of individualizing LPS
      can improve outcomes.

      Considering those results, it remains to clarify if there also exist thresholds of serum
      progesterone in modified natural cycles and stimulated cycles and if it's possible to improve
      the results through individualization of LPS the same way as it has been shown for
      substituted cycles.

      The intention of the present study is to carry out the determination of serum progesterone on
      the day of the embryo transfer to all those patients who are going to be subjected in IVIRMA
      Valencia to an embryo transfer in a modified natural cycle or a stimulated cycle.
    

Intervention name(s): PROGESTERONE AND ESTRADIOL SERUM CONCENTRATION MEASUREMENT
Intervention type(s): Procedure
Intervention description(s): The only intervention will be a single determination of serum P and E2 levels immediately before the embryo transfer.
Intervention MeSH terms: Estradiol; Progesterone
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        All infertile patients undergoing a fresh or frozen blastocyst transfer (two blastocysts
        transferred as maximum) from own or donated oocytes; in the context of a modified natural
        cycle (group A) or a stimulated cycle (group B). As usually performed in our daily clinical
        practice, all patients will receive hCG to trigger ovulation and maintain the corpus luteum
        to produce endogenous progesterone. Luteal phase support will be given as usual according
        to the routine in our center.
      
Keywords: Progesterone in luteal phase; modified natural cycle; stimulated cycle; clinical pregnancy rate; live birth rate