In Vitro Fertilization and Reproductive Medicine

In vitro fertilization (IVF), Intracytoplasmic sperm injection (ICSI) and Intracytoplasmic morphologically-selected sperm injection (IMSI) are reproductive technologies for fertility treatment of humans and animals. All those methods have in common, that eggs (ova) are removed from a female and fertilized outside the female’s body (in vitro) with sperms. Fertilized eggs (zygotes) are then implanted into the same or another female’s uterus to establish pregnancy.

In vitro fertilization (IVF)

  • eggs are harvested and incubated
  • unselected sperm cells are added
  • both are left together (in vitro) for several days
  • healthy, mobile sperm cells actively fertilize the eggs
  • embryos are transferred into the uterus

Intracytoplasmic sperm injection (ICSI)

  • eggs are harvested and incubated
  • the oocyte is stabilized by a holding pipette
  • a glass micropipette is used to collect a single sperm
  • the unselected sperm cell is immobilized by cutting its tail with the point of the micropipette
  • the oocyte is pierced through the membrane (oolemma) and the sperm is directed to the inner part of the oocyte (cytoplasm)
  • the sperm is then released into the oocyte
  • cellular structures such as the zona pellucida and polar body of the egg cell must be clearly visible

Intracytoplasmic morphologically-selected sperm injection (IMSI)

  • eggs are harvested and incubated
  • morphological selection of a healthy egg with an inverted microscope
  • the oocyte is stabilized by a holding pipette
  • semen analysis with an upright microscope
  • morphological selection of a healthy sperm cell with an inverted microscope with high magnifications, DIC contrast with oil immersion objectives
  • a glass micropipette is used to immobilize the selected sperm by cutting its tail
  • the oocyte is pierced through the membrane (oolemma) and the sperm is directed to the inner part of the oocyte (cytoplasm)
  • the sperm is then released into the oocyte
  • cellular structures such as the zona pellucida and polar body of the egg cell must be clearly visible
  • shape and vacuole count of the sperm cells must be assessed