Written by : Dr.M.D.Mazumdar, MD
A caesarian section is a surgical procedure carried out to extract a fetus from the uterus. The first caesarian section was believed to have been done to extract Julius Caesar from his dead mother at 9 months. Hence this procedure is called caesarian section. But reference to babies being extracted from their mothers by cutting the abdomen are also present in ancient Hindu, Roman and Greek literature. So, the reference to the birth of Julius Caesar being due to the first caesarian section may not be completely true .
About 10%-15% of all childbirths take place by caesarian sections. In some countries however, the rate may be as high as 27%.
A Caesarian section may be planned in advance (elective CS) or may be done due to an indication for caesarian section developing during labour (emergency CS).
Causes for Caesarian Sections:
1. Cephalo-pelvic Disproportion (CPD): CPD is a condition in which there is a disproportion between the size of the baby's head and the size of the inlet of the mother's pelvis. This disproportion may be due to:
a. Malposition of the fetal head - This is the commonest cause for a cephalo-pelvic disproportion (CPD ). Normally, the fetal head is in a position known as 'occipito-anterior' - this means that the fetal head is flexed so that the chin touches the chest and the upper part of the occiput of skull is towards the front of the pelvis. When the occiput is to the left side of the perlvis, it is known as left occipito-anterior (LOA). LOA is, by far, the most common position of the fetal head. Right occipito-anterior (ROA) may also occur but is less common.
The LOA position ensures that the narrowest diameter of the fetal head is available to pass through the pelvis. If any of these conditions are absent, that is, if the fetal head is not fully flexed (deflexed) or the occiput is to one side of the pelvis rather than to the front, or if the occiput is to the back of the pelvis (occipito-posterior), the fetal head diameter may be too large to pass through the pelvis. These conditions cause a cephalo (fetal head) pelvic disproportion and a normal childbirth will not be possible. A caesarian section may then become necessary to extract the baby from the uterus.
b. A large head and a normal sized pelvis - The head may be large if the baby's size is large as is often seen in maternal diabetes. It can also be very large in conditions like hydrocephalus (fluid collection in the baby's brain) or if the shape of the skull is abnormal - commonly seen in conditions like Down's syndrome or in neural tube defects.
c. A normal sized head but a narrow pelvis - The pelvis may be narrow in a woman who is physiologically of a small size or in women who has suffered from conditions like rickets or tuberculosis in her younger age - both these conditions may also cause the pelvis to be of an abnormal shape.
2. Fetal distress : Fetal Distress is the second most common condition necessitating a caesarian section. A fetus may show signs of distress in labour - the fetal heartbeat may increase or decrease beyond the normal range, the fetal heart beat may become variable and irregular, the fetus may pass meconium (fetal stool) into the liquor amnii or there may be decrease in oxygen saturation in the fetal blood. The commonest cause of a fetal distress is prolonged labour. While increased oxygenation and hydration along with some other treatment procedures may improve the fetal heart instability, it may be dangerous to wait for a normal delivery and the baby may need to be extracted by caesarian section as early as possible.
3. Placenta Praevia : Placenta Praevia is a condition in which the placenta is lowlying and covers the internal uterine os (uterine opening). The position of the placenta prevents descent of the fetal presenting part. There may also be moderate to severe bleeding during active labour. A caesarian section is the only option for a childbirth.
4. Maternal Health Problems : A Caesarian section may be needed in some conditions in the mother like PET , gestational diabetes , or heart problems in which the stress of a normal labour may affect the health of the mother or the baby. A previous caesarian section may also warrant a repeat CS.
5. Malpositions of the Fetus : In some women, the baby may not be in the normal cephalic (head down) position. If the baby is in the breech ( bottom down) position, a caesarian section may be needed. A breech position may also sometimes lead to a cord prolapse (prolapse of the umbilical cord through the cervical opening). This is an emergency and a caesarian section needs to be done as early as possible to save the baby. A CS may also be necessary in cases of transverse lie or unstable lie.
6.Accidental haemorrhage: Accidental Haemorrhage or Placental Abruption is a condition in which there is bleeding between the placenta and the uterine wall. A caesarian section needs to be done as early as possible to save the baby.
7. Blockages in the reproductive passage : Tumours like fibroids or polyps can block the uterine cavity at the opening and prevent descent of the baby for a normal childbirth. Vaginal septums or growths in the vagina can also block the vagina and a caesarian section may become necessary.
Procedure : The patient is prepped by insertion of an intravenous line to receive fluids and medicines. A catheter is inserted into the bladder to drain the bladder and keep it empty.
There are two types of anaesthesia offered during a casearian section. The commonest is the spinal anaesthesia in which the anaesthetic drug is injected into the sac that surrounds the spinal cord. The site of injection is at the lumbar region of the vertebral column, usually at the L2/3 or L3/4 space. This numbs and causes paralysis of the lower body. The patient is conscious during the childbirth but sedation may be given later if necessary. This is a safe type of anaesthesia since it does not affect the vital organs such as the heart, lungs and brain.
A general anaesthesia makes the patient completely unconscious and is used only if spinal anaesthesia is contraindicated or a general anaesthesia becomes necessary due to some other cause.
An epidural anaesthesia, in which the anaesthetic drug is injected into the lower back, outside the sac of the spinal cord, can also be used, but it is not as effective as the spinal anaesthesia in maintaning complete paralysis and numbness for the required duration of time. Hence, a spinal is preferred over an epidural for a caesarian section.
Once the lower body is numb, a transverse incision is made parallel to the pubic hairline. This is known as the Pfannensteil incision. A vertical incision along the the midline from the umbilicus to the pubic bone can also be made but this type of incision can cause more pain later on. Healing may also be delayed and risks of abdominal hernia may be increased. So, a transverse incision is preferred over the vertical. In emergency situations, the incision may be vertical since it can be done more quickly and the fetus extracted faster than in a Pfannensteil incision.
Once the incision is made, the abdomen is opened in layers and the uterus exposed. A similar transverse incision is made into the uterus and the baby removed from the uterus.
The baby is handed over to the paediatrician for examination and management. While this is done, the uterus is repaired and the abdomen closed in layers.
A caesarian section usually takes about 45 minutes to one hour.
Risks : The risks of a caesarian section are :
- Excessive Bleeding
- Injury to surrounding organs like the bladder and ureter.
- Postpartum Infection - either at the site of incision, the uterus or other pelvic organs
- Adhesions inside the uterus which can lead to future placenta praevia or fertility problems or a condition known as Asherman's Syndrome
- Extended stay in the hospital
- Extended recovery time, in the hospital, as well as later at home due to pain in the incision line.
- Negative reactions to the medications used during anaesthesia
- Risks of additional surgeries: Includes possible hysterectomy, bladder repair or another cesarean.
- Caesarian section babies are more likely to have breathing problems than babies born by normal delivery. This can be due to effect of the anesthesia, fetal distress before the delivery or lack of stimulation during delivery.