Which of the following is the major difference between GIFT and ZIFT?

GIFT (gamete intrafallopian transfer) is the transfer of ova (unfertilised eggs) into the woman’s fallopian tube and fertilisation occurs in vivo (in the fallopian tubes). ZIFT is the transfer of zygote (fertilised egg) into the fallopian tube after in vitro fertilisation. Both are invasive procedures and require the woman to have normal fallopian tubes.