A c-section is a very safe surgery and the risks of surgery are very few. The risks of any surgery are bleeding, infection, damage to other tissues, and anesthetic risks. The risks of c-section do increase with each subsequent c-section but the overall risk remains low even after multiple c-sections.
Bleeding can occur during c-section and this can occasionally become a problem. There us also the risk of bleeding with a vaginal delivery. If significant bleeding does occur, blood transfusion could be necessary. It is unusual to have enough bleeding to require blood transfusion, but this is necessary on occasion. Blood transfusion is very safe, but we still try to avoid this whenever possible.
Infections of the uterus, abdominal cavity, or wound can occur. These infections are rare. When they occur, antibiotics usually work very well to treat the infection. It is very rare to need additional surgery to treat the infection.
It is possible to have injury to other tissues during a c-section. This is a rare event. Previous surgery increases this risk due to scar tissue, but it is still unlikely to occur. If the bowels or bladder get injured, they can be repaired and typically heal very well. It is also possible to have injury to a nerve or blood vessel, but again this is very infrequent.
Placenta accreta is a rare condition in which the placenta grows into the muscle of the uterus. The risk of placenta accreta increases with each c-section but the overall risk is low even after multiple c-sections. Placenta accreta can cause severe bleeding. Transfusion is often necessary. Hysterectomy (removal of the uterus) can be needed to control the bleeding.
Each c-section causes scarring and the scar tissue tends to be worse after each subsequent c-section. The amount of scar tissue is variable and unpredictable. I have done repeat c-sections resulting in a tremendous amount of scar tissue and other repeat c-sections leaving very little. Scar tissue obscures the anatomy causing increased risk of injury to adjacent structures such as the bowels or bladder. Even with a lot of scarring these types of injuries are very infrequent.
People often ask me how many c-sections are allowed. There is no maximum number. Each c-section has a little more risk than the one before it. But the overall risk of c-sections is small even after many surgeries.