A Caesarean section, also known as C-section, is the use of surgery to deliver one or more babies. A Caesarean section is often performed when a vaginal delivery would put the baby or mother at risk. This may include obstructed labor, twin pregnancy, high blood pressure in the mother, breech birth, problems with the placenta, umbilical cord or shape of the pelvis, and previous C-section. A trial of vaginal birth in some of these situations, including after C-section, may be possible. Some C-sections are also performed upon request.