Sideways baby: labor challenges
If your baby is laying sideways in your belly that is called "transverse" position. If your baby is in the transverse position at the time of labor you will not be able to have a vaginal delivery.
Some doctors will attempt to manually turn your baby inside your belly so that you might be able to try for a vaginal birth. Turning the baby is usually very painful for the mother and it doesn't always work. Sometimes right after the baby is turned they flip back into the transverse position right away.
If you baby is in the transverse position at the end of your pregnancy your doctor will most likely recommend a c-section delivery.