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Mixing & Incubation of Eggs and Sperms are laboratory procedure. The process involves

  • Preparation of the Ova.
  • Collection and preparation of Sperms.
  • Insemination.
  • Fertilization and Incubation.
  • Embryo Transfer.

Preparation of the Ova After the oocytes collection procedure the follicular fluid containing the eggs is placed in a special nutrient culture medium. The eggs from it are then recovered and transferred to a sterile container to await fertilization in the laboratory. Not all of the eggs retrieved will be used for IVF. Unhealthy and immature eggs that fail to fertilize are not used. Any fertilized eggs that are not needed for transfer in this cycle may be cryopreserved for use in a later on.

The eggs remain in the carefully-controlled extracorporeal system for 4-6 hours before the embryologist adds the specially-processed sperm to allow the fertilization process to occur. The laboratory provides an efficient, safe transitional environment for oocytes from follicular aspiration until insemination. The goals are to recover all the oocytes in minimal time and evaluate their meiotic maturity and quality in preparation to insemination or sperm injection.

Sperms Preparation. Semen is usually collected after the egg collection but it can be done before if desired. The semen is specially treated to isolate the best quality vigorous, motile sperms. Swim up or Density Gradient procedures have been used. In azoospermia (no sperm in semen) there are three situations:

  1. Testes are atrophic without spermatids;
  2. Testes have spermatids but are not shed.
  3. Testicular function is normal. They produce sperms but there is obstruction in vas deferens; congenital or acquired. In later two situations sperms can be obtained for use in Intracytoplasmic Sperm Injection.
  1. from epididymus, its most proximal close to testes by
    • Microsurgical Epididymal Sperm Aspiration-MESA, open technique
    • Percutaneous Epididymal Sperm Aspiration-PESA s imply with syringe
  • Testicular Sperm Extraction-TESE. The sperm are extracted directly from the testicles when MESA fails to produce sperms.
  • Insemination 5-15 eggs are collected. In conventional IVF procedure motile sperms are added to the ova in culture medium. This mixture of ova and the sperms in culture medium is placed in Co 2 incubator. Typically the eggs are fertilized by adding approximately 100,000 motile sperm to each egg. The sperms penetrate the egg by their own energy and capability.
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