Pre-implantation diagnosis involves using molecular-biological tests to check the genetic status of embryos.

• After we harvest the eggs and fertilise them, we grow them for 3 days. Then, we take some cells from the embryos to test them. On the fifth day, we transfer the embryos. If we decide to grow the embryo for longer and take cells for testing from a 5-day embryo, we freeze it instead of transferring it.
  
  
• We use pre-implantation diagnosis when we need to check if there's a genetic problem with the embryo. We only transfer or freeze healthy embryos for later use.
  
  
• Pre-implantation genetic screening helps us check if embryos from IVF have the right number of chromosomes. This is important because about half of embryos can have the wrong number, which often leads to miscarriages.
  
  
• We usually take cells from embryos that are 5 days old. Then, we freeze the embryos and transfer them in the next cycle. One common chromosome problem is Down's Syndrome, where there are 3 chromosomes 21 instead of 2.
  
  
• We offer PGS to couples who have had many unsuccessful IVF attempts or repeated miscarriages before 12 weeks of pregnancy, especially women over 35.