PGS is a genetic screening performed prior to blastocyst transfer to detect any chromosomal number as well as structural abnormalities in the embryos when IVF is performed, with the aim of selecting normal embryos for implantation in the uterus. This is classified as chromosomal screening prior to transfer, which results in normal babies and improves the clinical pregnancy rate of the patient. This method belongs to the third generation of IVF and is particularly suitable for couples with hemophilia or thalassemia, who can be screened by doing PGS, chromosomal screening before blastocyst transfer, to directly find out if the blastocyst has this disease-causing gene. However, this IVF method can be more expensive and has certain indications, so you need to talk to your doctor before doing IVF.