Intra-cytoplasmic sperm injection (ICSI) is when a single sperm is used to fertilize each egg in an IVF cycle. ICSI is recommended if you are doing PGT-A, PGT-SR, or PGT-M. When ICSI is not used, results can show an extra set of chromosomes caused by extra sperm. This is called sperm contamination. In these cases, we cannot be sure if the embryo itself has an extra set of chromosomes (and will therefore not result in a healthy liveborn child) or if there was sperm contamination. Since there is a chance for incorrect results when ICSI is not used, Natera recommends that you use ICSI during your IVF cycle.