Fertilization failure

The fusion of an egg cell with a sperm cell is a critical step of the IVF fertilization treatment. Contrary to natural fertilization this step occurs in a small container rather than in the body of the woman.
IMPORTANT: It can occur that both in IVF treatment method as well as with an ICSI method only few egg cells are fertilized.

Following the traditional IVF – method

  • A so-called “rescue ICSI” on the day after the egg cell removal is attempted. After it has been determined on the first day that no sperm cell was able to independently fertilize an egg cell an attempt will be made to embed a sperm cell inside an egg cell using the ICSI method. However, the chances for success are reduced as the egg cell is already one day old.
  • Use of the ICSI method during the next treatment cycle is recommended.

Following the ICSI – method

  • Use of IMSI procedure, Intracytoplasmic Morphologically Selected Sperm Injection, in the next treatment cycle.
  • Use of PICSI procedure in the next treatment cycle.
  • Activation of the egg cells with Calcium Ionophore (CULT-active) during the next treatment cycle.

Rescue ICSI

Normally, the egg cell removal is followed by an IVF treatment on the same day and by the second day an assessment can be made as to whether an egg cell was successfully fertilized. If no egg cell has been fertilized by the second day, a fertilization failure is likely and a so-called “rescue ICSI” procedure can be performed.

The ICSI method involves a sperm cell being sucked into a microscopic needle and deposited directly into an egg cell.

The chances for fertilization using this technique are decreased as at this point the egg cell is already one day old. In case no fertilization occurs as a result of this method the ICSI method is recommended for the next treatment on the day of the egg cell removal.

IMSI (Intracytoplasmic Morphologically Selected Sperm Injection)

During a “classic” ICSI procedure a sperm cell is selected for injection after careful observation of the sperm sample under a microscope. The shape and speed of the sperm cell are the main factors for selection.

For some patients it is beneficial to carry out a more accurate selection of sperm cells based on their morphology.  The use of the IMSI method allows abnormalities, such as vacuolar or nuclear deformities, to be assessed by means of observation through a very high microscopic resolution.

We recommend the ICSI method to patients whose previous medical history includes:

  • miscarriages
  • a development stop of the embryo in earlier treatments
  • very fragmented embryos
  • very few regular shaped sperm cells observable in the semen analysis

IMPORTANT: This IMSI method is not routinely applied. The technique is time consuming and, according to the most recent research, only useful for certain patients. The above-mentioned criteria indicate whether this procedure would be beneficial in your case.

PICSI (Physiological Intracytoplasmic Sperm Injection)

This method involves the selection of a few sperm cells which bind well with hyaluronic acid. These sperm cells show statistically fewer genetic defects (so-called ‘DNA strand breaks”) and commonly contain a normal nucleus.

The injection with these specially selected sperm cells can improve the embryo quality and development. In order to perform the PICSI procedure sperm cells of a certain quantity and motility are necessary. Whether or not you can benefit from this method will be discussed during the consultation with your doctor. The new possibilities to examine DNA strand-breakage (SpermFertilityCheck) provide opportunities to select patients who can benefit from the PICSI method.

Oocyte activation with Calcium-Ionophore (CULT-active)

Calcium is important for the consequent cell proliferation. In cases of low fertilization results and abnormal embryo development a deficiency in calcium could be the cause. This means the sperm cell cannot activate the oocyte (no fertilization) or the oocyte cannot conduct the consequent cell proliferation successfully (delayed fertilization, embryonic development halt).

A solution for this problem is the artificial enrichment of calcium in the oocyte immediately after fertilization. This process is conducted using commercially available Calcium-Ionophore (CULT-active) which is licensed for this purpose. Immediately after the ICSI the ovocytes are immersed and washed in a suitable concentration of Calcium-Ionophor for 15 minutes. Afterwards they are cultivated in the conventional nutrient solution. In several studies the fertilization rate of the ICSI procedure and an improvement of the proliferation rates and development stages of the embryo were demonstrated. Problems in the fertilization of ovocytes based on reasons other than a calcium deficiency cannot be treated using this method (e.g. genetic abnormalities of the ovocytes or sperm cells).

The application of Calcium-Ionophor for fertilization problems has been conducted successfully for years. The indication of its use in cases of abnormalities in cell proliferation and development of human embryos is relatively recent and its success was scientifically proven during a clinical trial in 2014 in which the Kinderwunschzentrum Goldenes Kreuz participated.