Understanding the reasons and risks for a Caesarean section.

MOST women have vaginal deliveries. There are occasions when delivery is by Caesarean section (CS), which is an operation that involves a surgical incision made in the abdomen and uterus, through which the baby is delivered.

The operation can be planned (elective), in which the need for it is apparent during pregnancy, or unplanned (emergency), when the operation is necessitated by complications which arise during labour.

According to the National Health Care Establishments & Work Force Statistics published in 2011, the overall CS rate in 2009 was 20.8% of all deliveries. The CS rate in the private sector was 30.3%. The CS rate in the public sector was 18.1%, compared to 15.7% in 2006. The overall CS rate in Kuala Lumpur was the highest at 29.5%, compared to 11.5% and 11.6% in Sabah and Kelantan respectively.

Medical reasons for planned CS

There are several medical reasons, and they are discussed below.

The foetal position may be bottom first (breech). The obstetrician will usually offer an external cephalic version (ECV), which is a procedure in which an attempt is made to move the foetus round to head first with the obstetrician’s hands on the mother’s abdomen.

However, ECV cannot be done in mothers with certain conditions (contraindications). If so, or ECV has been unsuccessful, a CS is often offered.

CS is done if the foetus’ longitudinal axis in relation to the mother (lie) is transverse and ECV is contraindicated or unsuccessful.

Multiple pregnancy, usually twins, may be another reason. They may be premature, the first twin may be a breech presentation, or they may be sharing a placenta. However, CS is not indicated if the first twin is presenting by the head. It is not guaranteed that CS reduces the risks of twin delivery.

CS may be considered if the foetus is small because of prematurity or growth retardation, and other complications are present because of increased risks in-utero or around the time of birth.

CS is done if the placenta is sited at the cervical canal (praevia), the diagnosis of which is usually made at 32 to 34 weeks gestation. A colour ultrasound, and possibly magnetic resonance imaging (MRI), is often done to check if the placental attachment is abnormal (morbidly adherent placenta), which is another reason for CS.

CS is done if the mother’s pelvis is small in relation to the size of the foetal head; her blood pressure is very high; or she has a medical condition, eg heart problem, that increases her risk during a vaginal delivery.

CS may be considered if there are certain circumstances in a mother who has HIV, herpes or hepatitis to reduce the risk of transmission of the infection to the foetus during delivery.

An older mother’s chances of having a CS are increased because of increased risk of complications like high blood pressure, diabetes, large foetus, breech presentation, placenta praevia and slow progress.

Medical reasons for unplanned CS

An unplanned CS may be carried out for various reasons, ie concerns about maternal or foetal health, labour is not progressing, failed induction, or going into labour before a planned CS.

It may not be possible for the obstetrician to have a full discussion with the mother and/or her spouse in an emergency, especially when the baby needs to be delivered quickly.

Procedure

CS involves making an incision, usually almost horizontal, on the abdomen at the top of the pubic bone. This permits another almost horizontal incision in the uterine muscle to deliver the baby, after which the placenta separates from the uterine wall and is removed.

A hormone injection, which causes the uterus to contract, is given to reduce blood loss. The incisions are then stitched back together.

A vertical abdominal incision is made if there is a previous scar. A vertical uterine incision is made in certain circumstances like transverse lie, previous vertical incision (classical CS), etc.

CS is done under regional (epidural or spinal) or general anaesthesia. In the former, the lower part of the body will be numb, and the mother will be awake. A screen will be in place so that the mother does not have to see her operation.

In the latter, she will be asleep. There is an increased risk of vomiting, especially if the CS is unplanned. If this occurs, stomach contents can get into the lungs (aspiration) and cause serious inflammation (aspiration pneumonitis).

Eating during labour may increase the chances of aspiration. The risk of vomiting is reduced by not eating, but taking drinks with the same concentration of electrolytes and sugar as the body’s (isotonic drinks), antacids and medicines is allowed.

The operating table is slightly tilted during a CS to reduce the chances of low blood pressure from uterine compression of the abdominal blood vessels. A tube is usually inserted into the bladder (catheter) to empty it, and keep it empty.

After the CS, the mother will be observed by a trained nurse on a one-to-one basis until she is breathing normally and able to communicate clearly. The heart and breathing rates, blood pressure, and pain relief will be checked initially at half-hourly intervals and subsequently at hourly and longer intervals.

Pain relief will be provided with epidural analgesia, injections into the muscles or veins, tablets, or suppositories. The mother can control pain relief herself with injections into her veins (patient-controlled analgesia or PCA).

Antibiotics are not usually prescribed unless there is evidence of infection.

Fluids, and then food, can be taken soon if there are no problems. The catheter will usually be removed when the mother is mobile, or 12 hours after the last “top-up” of the regional analgesia.

There may be some difficulty initiating breastfeeding, but once started, breastfeeding will be no different from those who had a vaginal delivery. Care of the baby is no different from that of any other newborns.

The obstetrician will discuss the reasons for the CS before discharge from the hospital, or later if it is so preferred by the mother. The mode of delivery in future pregnancies should be part of this discussion.

The hospital stay is usually three to four days. Earlier discharge can be considered provided mother and baby are well, and there is adequate support at home.

Advice about post-natal care, possible complications of CS, pain relief, and wound care should be provided.

Medical attention should be sought if there increased, irregular or painful vaginal bleeding, pain on passing urine, leakage of urine, cough, pain or swelling in the legs, or breathing difficulties.

It will not be possible to carry out activities like exercise, carrying heavy things, having sex, or driving, immediately after discharge from the hospital. They can be started when one is able to, and they do not cause pain.

If unsure, a discussion with the obstetrician and/or midwife would be helpful.

Risks

The risks to the mother include infection of the wound and/or the uterus, excessive bleeding that may require removal of the uterus (hysterectomy), damage to the bladder or the tube that connects the kidney to the bladder, blood clots (thrombosis) in the legs or pelvis, which may be life-threatening if part of it dislodges and goes to the lungs (pulmonary embolism), and longer hospital stay.

There are also risks to the baby. Accidental cuts on the baby’s skin when the uterus is incised occur in about two in 100 babies delivered by CS.

The most common risk is that of breathing difficulties, which occur in about 35 out of 1,000 babies delivered by CS, compared to five in 1,000 babies delivered vaginally. Their breathing may be more rapid immediately after birth and the first few days of life (transient tachypnoea). This usually resolves within two to three days. The risk of baby’s admission to intensive care may also be increased.

The risks of anaesthesia to mother and baby have to be considered too.

Planned CS may reduce the risk of pain in the area between the vagina and anus (perineum), and injury to the vagina.

The risks to mother and baby are usually increased in unplanned CS due to problems in pregnancy or labour.

A CS does not increase or decrease the risk of breastfeeding problems, postnatal depression, other psychological problems or pain during sex.

A CS does not increase or decrease the risk of the baby having serious complications like bleeding in the skull, cerebral palsy, nerve injuries or death. These rare complications affect less than 20 in 10,000 babies.

Reducing the chances of CS

The measures include having another person for support throughout labour, induction at 41 weeks gestation, use of a chart (partogram) to monitor the progress of labour, availability of foetal blood sampling if electronic foetal monitoring is used, and decision-making by a senior doctor, usually a consultant obstetrician.

The obstetrician will discuss the reasons whenever a patient requests a CS. If there are no medical reasons for the CS, an explanation of the risks and benefits compared to vaginal delivery should be provided.

It is also essential to have a discussion with the anaesthetist and paediatrician. If there is anxiety about giving birth, arrangements can be made for discussions with healthcare professionals who can provide support during pregnancy and labour.

Some obstetricians will accede to a patient’s request for CS although there are no medical reasons. If the obstetrician is unwilling to do a CS for non-medical reasons, a referral to another obstetrician who does may be considered.

Source: Dr Milton Lum