Childbirth: Reasons for Cesarean Delivery

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Childbirth: Reasons for Cesarean Delivery

Topic Overview

A baby can be born in one of two ways. A vaginal birth is one in which the baby is delivered through the mother's birth canal (vagina). A caesarean birth (C-section) is one in which the baby is delivered through an incision in the mother's lower abdomen and uterus. A caesarean birth is a surgical procedure done with anesthesia. It can take 4 to 6 weeks to recover completely from the surgery, although most mothers are up and able to care for their infants in 3 to 4 days.

A C-section may be done when a quick delivery is needed for the safety of the mother or baby. Some caesareans are performed after labour has slowed or stopped and a manual examination shows that the fetal head is not engaging in the pelvis. This sometimes happens when the fetal head is larger than the mother's pelvic girdle (cephalopelvic disproportion).

Some conditions or problems that may require a caesarean birth can be identified before labour begins. These conditions include the following:

  • The baby's feet or buttocks are positioned toward the cervix (breech position).
  • The placenta is blocking the cervix (placenta previa).
  • The mother has open sores caused by genital herpes when labour begins. Herpes can be passed to the fetus during delivery and cause serious problems.
  • The mother has a disease or condition that may be made worse by the stress of labour.
  • The baby is firmly estimated to be over 5 kg (11 lb), or over 4.5 kg (10 lb) for a mother who has diabetes.1
  • The blood supply to the placenta is decreased before birth, most often because the mother develops high blood pressure during pregnancy, or pre-eclampsia. (Usually, the doctor or midwife tries to induce labour first.)
  • The fetus is 2 or more weeks overdue (post-mature). When pregnancy lasts past 42 weeks, the aging placenta may not provide enough oxygen and nutrients to the fetus. Usually, the doctor first tries to induce labour. If induction does not work, a caesarean birth is necessary.

Many caesarean births are done on an emergency basis when maternal or fetal problems or complications develop during labour. Such situations include:

  • Fetal distress (suggested by a very rapid or very slow heart rate).
  • Difficult, slow labour (dystocia).
  • Labour that has stopped completely (failure to progress).
  • Cephalopelvic disproportion, a combination of a large fetal head and a mother's narrower pelvic structure. This condition is often linked to failure to progress, or dystocia.
  • Abruptio placenta, which can cause excessive bleeding (hemorrhage) and decreased oxygen supply to the baby.
  • Umbilical cord problems. Examples include:
    • Cord prolapse, when the cord has slipped into the birth canal ahead of the baby. When the baby moves into the birth canal and presses against the cord, the blood (and oxygen) supply can be cut off.
    • When the cord is torn during delivery, decreasing the baby's blood supply.

In the past, a woman who had one caesarean birth then had to have all of her other babies delivered by caesarean also. This is no longer the case. Depending on the reason for the original caesarean and the type of incision that was made, a woman may be able to deliver her next baby vaginally. For more information, see the topic Vaginal Birth After Caesarean (VBAC).



  1. American College of Obstetricians and Gynecologists (2000, reaffirmed 2008). Fetal macrosomia. ACOG Practice Bulletin No. 22. Obstetrics and Gynecology, 96(5): 1–11.


By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Primary Medical Reviewer Sarah Marshall, MD - Family Medicine
Primary Medical Reviewer Donald Sproule, MD, CM, CCFP, FCFP - Family Medicine
Specialist Medical Reviewer Kirtly Jones, MD, MD - Obstetrics and Gynecology
Last Revised February 18, 2010

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