Biochemical Pregnancy Loss


Biochemical pregnancy loss (BPL) is a very frequent issue in human reproduction. After the implantation of the embryo, hCG disappears very soon from the maternal bloodstream and no evidence of a clinical pregnancy is seen. Different studies showed that factors such as age, the oocyte and embryo quality, and endometrium receptivity may have something to do with the occurrence of biochemical pregnancy loss post-ART.

The main aim of this study is to evaluate the incidence of biochemical pregnancy loss (BPL) in three different cohort populations; patients undergoing frozen embryo transfer (FET) from own oocytes after preimplantation genetic testing for aneuploidy (PGT-A), patients undergoing FET from own and donated oocytes and with endometrial receptivity array (ERA), and patients undergoing FET from own or donated oocytes (without PGTA or ERA test).

We will analyse the incidence of BPL in these populations and try to determine the role of the euploid status embryo in the first group, the endometrium in the second group and the third one as control group. We are waiting to find the value of both players in the origin of BPL.

Full Title of Study: “Is Biochemical Pregnancy Loss Associated to Embryo or Endometrium? A Multicenter Retrospective Study”

Study Type

  • Study Type: Observational
  • Study Design
    • Time Perspective: Retrospective
  • Study Primary Completion Date: January 15, 2020

Detailed Description

Human embryo implantation is a poorly understood process. Once the embryo implants in the endometrium, it starts to secrete hCG that can be measured in the maternal blood as early as 9 days after implantation. Only a minimal number of pregnancies get to new born, and the majority are lost before reach the first trimester (Larsen et al., 2013).

We are looking for the role of the embryo after controlling its chromosomal ploidy, and the endometrium after controlling its transcriptomic expression. We will also use a no exposed group to the controlled euploid embryo factor neither endometrial factor that is the oocyte donation group. This analysis expects to provide more information about the key role of embryo or endometrium in BPL.


  • Other: collect retrospectively data
    • Analyse the incidence of BPL in these populations

Arms, Groups and Cohorts

  • preimplantation genetic testing for aneuploidy (PGT-A) Group
    • Patients who have undergone preimplantation genetic testing for aneuploidy (PGT-A) (transfer of own frozen embryo)
  • endometrial receptivity array (ERA) Group
    • Patients who have undergone frozen embryo transfer (FET) with endometrial receptivity array (ERA) test (embryos from own or donated oocytes)
  • CONTROL OWN (CO) Group
    • Control group of FET from own oocytes (without ERA or PGT-A)
    • Control group of FET from donated oocytes (without ERA or PGT-A)

Clinical Trial Outcome Measures

Primary Measures

  • Biochemical pregnancy loss (BPL)
    • Time Frame: Since 2013 to april 2019
    • when the maternal serum levels of β-hCG are higher than 10 UI/L, but in the transvaginal ultrasound is not possible to appreciate any gestational structure (dichotomous qualitative variable: yes/no). This variable is considered as the fraction between patients whose β-hCG is higher than 10 UI/L, without clinically recognized pregnancy, by number of pregnant patients.

Participating in This Clinical Trial

Inclusion Criteria

Patients with the following selection criteria:

  • IVF/ICSI patients aged between 18 and 44
  • BMI 18-30 kg/m2
  • Frozen embryo transfer from own oocytes after PGT-A
  • Frozen embryo transfer with ERA test (from own or donated oocytes)
  • Frozen embryo transfer (from own or donated oocytes)
  • Single embryo transfer (SET) in all cycles
  • Patients without uterine malformations
  • Patients without recurrent miscarriage (≥ 3)
  • Patients with adequate endometrial thickness (> 7mm)
  • Patients without thyroid autoimmunity
  • Patients without thrombophilia
  • Exclude cycles with exclusively PGT-M
  • Exclude FET in ovarian stimulated cycles

Exclusion Criteria

Exclude cycles with exclusively PGT-M Exclude FET in ovarian stimulated cycles

Gender Eligibility: Female

Minimum Age: 18 Years

Maximum Age: 44 Years

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • IVI Vigo
  • Collaborator
    • Instituto Valenciano de Infertilidad, IVI VALENCIA
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Elkin DR Muñoz, MD, Principal Investigator, IVI Vigo

Citations Reporting on Results

Díaz-Gimeno P, Horcajadas JA, Martínez-Conejero JA, Esteban FJ, Alamá P, Pellicer A, Simón C. A genomic diagnostic tool for human endometrial receptivity based on the transcriptomic signature. Fertil Steril. 2011 Jan;95(1):50-60, 60.e1-15. doi: 10.1016/j.fertnstert.2010.04.063. Epub 2010 Jul 8.

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