Multiple fetuses are often delivered early. Most doctors try to delay delivery of twins until about the 37th week pregnancy, but the average twin pregnancy is delivered at 35 weeks .

Although the ideal time for delivery of triplets is 35 weeks, the average length of pregnancy for triplets is 33 weeks. Quadruplets are delivered, on the average, at 29 weeks.

How multiple fetuses are delivered often depends on how the babies are lying in the uterus. All possible combinations of fetal positions can occur.

When both twins are head first, a vaginal delivery is usually attempted. One baby may be delivered vaginally, with the second requiring a C-section if it turns, if the cord comes out first or if the second baby is distressed after the first one is born. Some doctors believe two or more babies should always be delivered by Cesarean section.