Implantation failure and repeated miscarriage unit

Implantation failure requires a specialized treatment that is provided at Instituto Bernabeu by a specific multidisciplinary unit.

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What is implantation failure?

It is defined as a failed attempt to achieve a viable pregnancy by means of IVF. That is, it encompasses both those patients who fail to become pregnant and those patients who become pregnant but have an early miscarriage.

Unidad de fallo de implantación embrionario

Why does embryo implantation failure happen?

It is a challenge to answer this question because we are unaware of many processes that result in a successful embryo implantation.

To begin with, it must be kept in mind that the cause cannot be attributed to a single patient (the mother) but to THREE: her, him and the embryo.

True, we know that some causes are related to the mother, but most of them have to do with the embryo, and they cannot always be diagnosed or treated satisfactorily. Hence the patient’s high degrees of uncertainty and anxiety when doctors cannot find them.

Nevertheless, great progress has been made in this field over the last years.

An accurate study of implantation failure requires a multidisciplinary assessment. For this reason, a working group that specializes in these disorders was created at INSTITUTO BERNABEU. This group includes gynecologists, endocrinologists, molecular biologists, geneticians and embryologists.

Implantation failure and repeated miscarriage unit

An analysis for diagnosing embryo implantation failure and recurrent pregnancy loss

Implantation failure and repeated miscarriage unit

Female Factor

Whilst we still have a long way to go before we fully understand the female factors that explain implantation failure and recurrent pregnancy loss, there have been some new findings on the subject. 


Three-dimensional ultrasound scans performed by expert sonographers plus sophisticated equipment mean that it is possible to rule out adenomyosis, a well-known cause of endometrial receptivity loss and anatomical abnormalities in the uterus.

However, immunology analyses rarely help and any treatment derived from these analyses often fails to have a positive impact of any kind. That said, and taking into account the fact that this field is in continuous development, we have a Reproductive Immunology Department at IB that assesses this factor and carefully monitors any progress that is made.

We also carry out studies on uterine contractions when embryo transfer takes place. We must not forget that the uterus is a muscle and, therefore, any inappropriate stimulation of the uterus increases contractions that could lead to expulsion of the embryo.

An ultrasound video studying contractions and measuring progesterone levels is incredibly useful in ruling out and treating this cause.

Last of all, at Instituto Bernabeu we are undergoing studies on the efficiency of placing substances that stimulate the endometrium inside the uterine cavity days before transfer in order to increase biological competence

It is clear to see that analysing the maternal factor calls for a multiple assessment approach.

We also perform a study called IBgen RIF that includes a genetic, immunological and haematological factor panel meaning that a single test can provide us with information about different causes.

Our most recent research work has demonstrated the impact of the microbiome (the microorganisms that live around the genitalia) on fertility. This prompted us to begin analysing it so that measures can be taken if abnormal results are obtained. (Learn more).

Implantation failure and repeated miscarriage unit

Male Factor

The MALE FACTOR is studied through the karyotype, DNA fragmentation, an andrology-based exploration and chromosome assessment. 


A karyotype (an analysis of the number and arrangement of chromosomes) performed on blood cells can return an entirely normal result. However, this may not be the case for the chromosomes in spermatozoa. This is why we include a test called FISH in the analysis. This test assesses an elevated number of spermatozoa, usually in excess of 1,000, in order to obtain an understanding of their chromosomal make-up.

Implantation failure and repeated miscarriage unit

Embryo Factor

However, the EMBRYO FACTOR is undoubtedly the area in which most progress has been made.

It is clearly responsible for most cases of implantation failure and recurrent pregnancy loss. 


It should not be forgotten that this stems from the combination of two reproduction cells: the spermatozoon and the oocyte. Therefore, exquisite care when it is being processed, strict tracking of development and of the culture conditions in the laboratory and the delicate transfer to the mother’s uterus must be taken very much into account when explaining previous failures.

Indeed, these days molecular and genetic biology techniques make it possible to analyze all of the embryo’s chromosomes, as the most common cause for implantation failure and early miscarriage is an anomalous number and constitution of embryo chromosomes.

The transfer of chromosomally normal embryos makes pregnancy rates remain the same regardless of the mother’s age. At the same time, miscarriage risks decrease dramatically. In other words, whenever embryos that are free from chromosomal abnormalities are transferred, patients will always have the same expectancy for success regardless of their age.

This technique, known as CCS (Comprehensive Chromosomal Screening)(Preimplantation Genetic Screening (PGS), Preimplantation genetic testing for aneuploidy (PGT-A)), is used around the fifth day of the embryo’s development and is proving to be greatly effective to answer the most relevant questions for patients and for the doctors that take care of them. Why do embryos fail to implant? Why do they miscarry? Is the treatment worth repeating? Is it time to leave it or change it?

Comprehensive Analysis 1 day

Given our high degree of specialisation in recurrent pregnancy loss / implantation failure, we are able to bring together all the specialists involved in analysing your case during your medical consultation and carry out all the diagnostic tests required in order to analyse and design your personalised course of treatment in just one day.

     Female partner:

  • Personalised analysis of your medical history
  • Hysteroscopy and endometrial biopsy. Functional study of the endometrium and CD138 antibody marker for a specific analysis of chronic endometritis
  • Implantation failure genetic risk profile
  • Tests for thrombophilia
  • Immunological tests
  • Thyroid function tests: TSH and anti-TPO
  • Karyotype
  • Vitamin D
  • Genital microbiome analysis
  • Evaluation of the uterus using high-resolution ultrasound imaging
  • Study, if appropriate, of uterine contractility and progesterone levels on the day of embryo transfer.

     Male partner:

  • Karyotype
  • DNA fragmentation study (TUNEL)
  • Sperm FISH

     Embryo profiling:

  • PGS/PGT-A/CCS

Personalized analysis of your medical history.

Do you need help? 
We can help you with a no-obligation