一次怀孕两个或两个以上胎儿时,称为多胎妊娠,这些胎儿就叫多胞胎,有双胞胎、三胞胎、四胞胎……。多胞胎是个自古就有的现象,可以说自从有人类始,就有多胞胎,可是那时都是天然而成,而且发生率较低。而自从本世纪中期以来,由于人工对生育的干预,特别是从1978年世界上第一例试管婴儿诞生以宋,多胞胎的发生率是骤然升高了,已经到了令人忧虑的地步。 A pregnancy when two or more fetuses, called multiple pregnancy, these fetuses are called multiple births, twins, triplets, quadruplets ... .... Multiple births are phenomena that have existed since ancient times. It can be said that there have been multiple births since the beginning of humankind, but at that time all of them were made in nature and occurred at a lower rate. And since the middle of this century, the incidence of multiple births has risen alarmingly due to the artificial intervention in procreation, especially since the birth of the first IVF in 1978 in the world.