In general, C-section births may be indicated when:
The baby is "breech" - meaning his or her head is not positioned down, toward the cervix. If labor begins for a breech baby, it may be difficult because the hips, or even the feet, may be the first parts entering the birth canal. This can lead to the umbilical cord being trapped in the pelvis and compressed, reducing or cutting off blood supply to the baby.
The placenta sits very low in the mother's womb - a condition called placenta previa. If the placenta is too close to, or is covering, the cervix, a C-section birth is necessary so the placenta does not tear or detach during labor. Laboring with a placenta previa can result in massive hemorrhage of the mother and of the baby.
The baby's heart rate is slowing too much during labor. This situation can occur for a number of reasons, but may be due to the umbilical cord being compressed within the womb or by having a compromised placenta. Doctors will assess the baby's heart rate and may decide on a C-section delivery rather than letting labor progress.
Previous C-section birth. Most women who have had a previous C-section can have a successful vaginal delivery, although they must be carefully monitored during labor. However, for some women, the risk of rupture of the uterus is too high and avoiding active labor may be the best choice.
Additionally, other medical conditions in the mother or the baby may lead to a decision to choose a C-section delivery.
A C-section should not be considered for scheduling convenience alone, as the risks of an elective C-section are generally much higher than a normal vaginal delivery. Letting a healthy pregnancy develop to full term, following the natural course of labor, and proceeding to a vaginal delivery, is truly ideal.