Why is there a time gap between the birth of twins?

Q: When a woman delivers twins, why don't the babies come out immediately one after the other? Why is there a time difference like 5-15 minutes or hours etc. between the delivery of two babies?

A:The interval between the birth of each baby delivered vaginally is usually less than an hour (but can be much longer too). This is because of the time required by the uterus to contract and push out the baby and the two placentas to separate.