Multiple pregnancy is a pregnancy when the mother delivers two or more offspring. Multiple births can occur in most of the mammals and such births are named according to the number of offspring. It can occur as a result of either fertilization of multiple eggs creating fraternal fetuses or a result of a single fertilized egg that got divided, creating identical fetuses or maybe a combination of both factors. Multiple pregnancies which occur from a single zygote, double zygotes and more zygotes are termed as monozygotic, dizygotic and polyzygotic respectively. A few of the complications associated with multiple pregnancies are gestational hypertension, premature labor, fetal growth restriction and placenta abruption. This book includes some of the vital pieces of work being conducted across the world, on various topics related to multiple pregnancy. It provides comprehensive insights. This book will help new researchers by foregrounding their knowledge in this branch.