Failure of Implantation After Recurrent Embryo Transfers
Condition: Infertility
MeSH terms: Infertility
Study type: Observational

Summary: 
      We will investigate maternal and embryonic factors in women with recurrent implantation
      failure, undergoing IVF/ ICSI treatment. Women who have not achieved a pregnancy after three
      embryo transfer procedures will undergo an endometrial biopsy during the window of
      implantation in a natural cycle. During the next treatment cycle we will aspirate endometrial
      secretion and perform a doppler ultrasound investigation of the a. uterina. Moreover, we will
      investigate the cytokine expression from the transferred embryo from the culture medium.
    

Detailed description: 
      Rationale:

      Despite advances in IVF procedures and the transfer of embryos of high morphological quality
      embryos, pregnancy rates from IVF remain around 30% per embryo transfer procedure. Failure of
      the transferred embryo to implant remains the most important limiting factor determining in
      vitro fertilization (IVF) or intra cytoplasmic sperm injection (ICSI) success rates. If
      progress is to be made in improving implantation rates, a greater understanding of the
      factors which determine successful implantation is required. Recurrent implantation failure
      after IVF may be due to an endometrial, and embryo problem or both. All women entering our
      IVF program undergo pre-conceptional counseling and a pre-treatment blood withdrawal for
      hormonal investigation and investigation of uterine cavity by ultrasound examination,
      hysteroscopy and endometrial biopsy. The data generated by this pre-treatment screening
      potentially enables factors predictive of implantation failure to be identified. In addition,
      study of the further IVF cycle will increase our knowledge of the factors of endometrial and
      embryo factors involved in implantation failure, and aid in the characterization of the
      different causes of this distressing clinical problem. On the basis of these data, rational
      interventions designed to improve outcome can be designed and tested.

      Objective:

      To delineate pre-treatment predictors of recurrent implantation failure, to characterize the
      different phenotypes of women suffering from this problem and to study the relative
      importance of maternal and embryonic causes of implantation failure.

      Study design:

      Prospective, controlled cohort study.

      Study population:

      50 women who have received at least 3 embryo transfers in previous IVF cycles carried out
      within the UMC Utrecht, without achieving a clinical pregnancy. The control group of 'normal
      implanters' consists of 30 women who have previously readily conceived following ICSI for the
      treatment of severe male subfertility.

      Main study parameters/endpoints:

        1. Retrospective analysis of screening parameters, including analysis of endometrial biopsy
           material for Noyes criteria of endometrial dating, uterine natural killer (uNK) cell
           count and dietary/ lifestyle parameters obtained by questionnaire during
           pre-conceptional counseling.

        2. Analysis of uNK cell count obtained from luteal phase endometrial biopsy prior to the
           treatment cycle.

        3. Analysis of endometrial secretion and embryo culture medium cytokine expression profile
           measured at the time of embryo transfer in a subsequent IVF cycle: comparison with
           normal profile identified in the ICE study.

      Nature and extent of the burden and risks associated with participation, benefit and group
      relatedness:

      Much of the data to be analysed will be collected from routine clinical work up
      (pre-conceptional screening). Women with recurrent implantation failure then embarking on a
      further IVF cycle will be invited to participate in this study and will undergo additional
      investigation. This will include an endometrial biopsy prior to the treatment cycle, and
      endometrial fluid aspiration prior to embryo transfer in the subsequent treatment cycle. No
      negative effect on pregnancy rates from these interventions have been reported. The
      theoretical risk associated with the aspiration of endometrial secretion before embryo
      transfer might be disruption of embryo implantation. However, our group has developed a
      technique which, as we have previously shown, does not disrupt the process of implantation.
    

Keywords: IVF; endometrial receptivity; embryo implantation; recurrent implantation failure