Fertilization / Implantation Support

The new embryo is created by the fusion of a sperm cell with an egg. This process is called fertilization.

Fertilization can occur naturally in the woman’s fallopian tube or in the IVF laboratory with the help of assisted reproduction . There are two techniques for fertilization in an IVF laboratory: classic in vitro fertilization (IVF) or fertilization by micromanipulation of a sperm and egg, called ICSI (intracytoplasmic sperm injection).

Like any other biological process, fertilization is not perfect and sometimes fails: even if spermatozoa, like eggs, look completely normal and the assisted fertilization technique (IVF or ICSI) is technically flawless, in some cases fertilization does not occur. The measure of fertilization is the so-called fertilization rate, i.e. the number of fertilized eggs divided by the total number of eggs retrieved.

The fertilization rate of assisted reproduction (either classic IVF or ICSI) is 70-80% in modern laboratories – so it is considered very successful. Please note: However, this still means that 2 to 3 out of 10 retrieved eggs may not be fertilised!

Total fertilization failure (TFF) is when fertilization fails in all the eggs removed. While total fertilization failure is rare (1-4% of all patients), it is extremely frustrating for both patients and our fertility team. Unfortunately, our understanding of this phenomenon is still rudimentary. Risk factors for fertilization failure include an advanced age of the patient (>38) when only a small number of eggs can be retrieved, morphological abnormalities of the oocyte and poor sperm quality. Unfortunately, there is currently no diagnostic test that can predict TFF. TFF can occur repeatedly in the same couple.

There are several additional laboratory procedures that we can use to try to overcome fertilization failure:

– “Rescue” ICSI: application of the ICSI method the day after IVF, if fertilization failure has occurred

– ” Preventive” (“repeated”) ICSI: use of ICSI in every future attempt, even in cases where classic IVF fertilization would otherwise be used

– Calcium ionophore as an adjunct to ICSI to initiate the fertilization process (studies have shown that increasing the concentration of calcium in the egg can increase the fertilization rate and can also favor the implantation of the resulting embryo)

– PICSI (physiological ICSI): modified ICSI, in which the most functional spermatozoa are specially selected for intact genetic material with a higher probability before ICSI

Please note: All of the above additional procedures require informed consent and will only be used after thorough analysis of the case and in-depth discussion with patients.

Please note: There is no one hundred percent solution when it comes to total fertilization failure. Even if all the additional laboratory techniques proposed are used, there is a possibility that the (low) fertilization rate will remain unchanged.

We will be happy to explain further details and possibilities to you in detail during your initial consultation.

Implantation isthe process of attaching the developing embryo to the uterine wall. It is an extremely complicated process in which a completely foreign organism – the embryo – forms a bond with the mother’s body in order to absorb all the substances necessary for its development and to excrete waste products. Pregnancy begins the moment the embryo implants.

Even though the embryo is an extremely efficient “parasite”, we humans are not exactly the great success story of natural reproduction (according to Wilcox AJ et al. Preimplantation loss of fertilized human ova: estimating the unobservable. Hum Reprod. 2020. 35(4): 743-750):

– Up to 60% of fertilized eggs are lost before implantation.

– Another 30% of implanted embryos are lost during early pregnancy.

Natural selection is one of the most powerful forces of nature and favors the birth of genetically unencumbered, well-viable organisms. The implantation of an embryo is a particularly central time for (natural) embryonic selection, which is why there seems to be large embryonic losses before, during and shortly after implantation.

There are two specific groups of patients who have problems when trying to conceive beyond naturally expected implantation rates. In the first group, implantation does not occur (implantation failure). The other achieves implantation but is unable to maintain an early pregnancy (repeated miscarriages).

Unfortunately, our knowledge of implantation and early pregnancy is far from satisfactory: the cause of implantation failure or repeated miscarriages currently remains unknown in up to 70% of cases.

If you have implantation problems or have suffered two or more recurrent miscarriages after IVF/ICSI treatment , we will treat you with special attention at ReproCreate Fertility Clinic.

We will do our best to determine the cause of your problem and to personalize your treatment if possible according to the state of the art.

If the cause of the failed implantation or recurrent miscarriage remains unclear, we will analyze all available options and then decide together which treatment is best for your situation.

Please note: Proposed treatments for implantation failure/recurrent miscarriage are still under development, and there may be conflicting data in the literature. We cannot guarantee a solution to the problem of implantation or .dem preservation of pregnancy.

Please note: Implantation failure/recurrent miscarriage treatments are associated with additional costs. If you are interested in such treatment, we will be happy to take the time to provide you with the necessary information for your informed consent and to answer all your questions in the best possible way.

The additional treatments we can apply in case of implantation failure/recurrent miscarriage include:

– Assisted hatching: “assisted hatching”, in which a small hole is made in the shell of the embryo by means of a laser to facilitate the hatching process

– EmbryoGlue: “Embryo glue “, a special medium for embryo transfer designed to facilitate implantation

– PICSI: physiological ICSI, a modified ICSI fertilization method in which the spermatozoa are tested and the most functional ones are selected

– Timing of embryo transfer after ERA test: “Endometrial Receptivity Array”, testing the receptivity of the endometrium to determine the optimal implantation window for embryo transfer

– Scratching: “scratching ” the endometrium (lining of the uterus) to improve the probability of implantation

– Optimization of the endometrial microbiome

– HCG irrigation: Irrigation of the uterus with the pregnancy hormone HCG

– Clarification and treatment of a possible chronic inflammation of the cervical membrane (endometritis)

– Confirmation and treatment of the dysregulation of endometrial NK cells (natural killer cells)

– Intralipid infusion to suppress the activity of natural killer cells

– IVIG infusion: “passive immune treatment” by infusion of immunoglobulins

We will be happy to explain further details and possibilities to you in detail during your initial consultation.