IVF stands for in-vitro fertilisation, which means the fertilisation of eggs by sperm outside the body.

Since the first “test-tube baby” in 1978, this method of fertilisation has been continually developed and improved. Nowadays, IVF is the leading establish method of artificial reproduction.

In IVF, the ovaries are hormonally stimulated through self-applied injections, so that several eggs mature.

36 hours after the triggering of the ovulation with a hormone injection (such as hCG), the eggs are extracted from the ovaries by suction. This procedure takes place under a light anaesthetic.

A vaginal ultrasound is used and with the help of a conductor attached to the head of the ultrasound, the puncture needle can be accurately manoeuvered through the upper part of the vagina directly to the ovaries, where the follicle fluid containing the eggs is sucked from the oocytes (follicle puncture). This is a gentle procedure with very few complications.

After the delivery of the sperm and the processing of it using wash and centrifugation processes, the eggs and sperm are then put together in a nutrient solution. The sperm then start penetrating the eggs without needing any further artificial assistance. About 50 - 70% of the eggs are fertilised using this method.
The fertilised eggs then develop into embryos:

• Day 1 after the egg puncture = pre-nuclear stage (pronuclei)
  
  
• Day 2 after the egg puncture = two to four cell stage
  
  
• Day 3 after the egg puncture = eight cell stage
  
  
• Day 4 after the egg puncture = morula stage
  
  
• Day 5 after the egg puncture = blastocyst
  (expanding or hatching)
  

Delay in this development schedule can indicate a possible flaw in the embryo, along with the inability for it to develop further and achieve nidation. Only 50% of the pre-nuclear stages reach the blastocyst stage!

Using a plastic catheter, up to two embryos are then implanted into the womb, three to five days after the puncture. This procedure is called embryo transfer. Most of the embryos are, at this time, in the blastocyst stage.