 This is an advantage because PGD methods such as FISH are able to reveal whether an embryo will express the phenotypic difference, but not whether an embryo may be a carrier.In 2015, PGH was used in conjunction with a whole-genome amplification (WGA) process to not only diagnose disease but also distinguish meiotic segregation errors from mitotic ones.Studies are being continually performed in an attempt to utilize and improve PGD methods since their initial invention.