ABSTRACT
Bearing in mind these points, the following definition of multiple pregnancy is proposed. Irrespective of the final number of fetuses/neonates, a multiple pregnancy is the result of intracorporeal development of more than one zygote and/or the intracorporeal development of a split zygote, which was produced in the same or in a different ovulatory cycle. Only the future will reveal whether the definition is sufficiently comprehensive for all types of spontaneous and iatrogenic multiple pregnancies.
