C-section. Unfortunately, a transverse position in pregnancy can be a dangerous situation. Once labor starts, typically the lowest part of the baby to enter the birth canal is the baby's shoulder. Hundreds of years ago, this situation would be fatal complication, because the baby could never fit through the birth canal...But today, a safe and timely c-section would prevent injury to both mom and baby.
See below. If the child does not move into either the head down or breech position then the OB doctor may want to try an external version. This is an attempt to move the baby into a better position for delivery. If this fails the only option for delivery might be a c-section.