Caesarean Section
ByDr. Afraa Mahjoob Al-Naddawi
FIBOG, CABOG
Caesarean section (C/S):
It is a surgical procedure in which incisions are made through the mother’s abdomen (laparotomy) and uterus (hysterotomy) to deliver one or more babies.In the UK, more than 21% of all babies are now delivered by C/S; In 1985 concern regarding the increasing frequency of C/S lead WHO to held a conference which concluded that there were no health benefits above a caesarean section rate of 10-15%.
Factors that may contribute to an increase in the rate of C/S:
• Inaccurate dating of the pregnancy: accurate dating reduce the anxiety experienced by many women when they pass their EDD and also reduces the request for early induction of labor, this dating is very important in units where a policy of offering routine induction of labor to women who are 41 weeks gestation or more.• Fetal monitoring: when electronic fetal monitoring was introduced, it was universally implemented and this has resulted in an increase in caesarean section incidence without demonstrable improvement in the perinatal outcome.
• Current recommendations are for intermittent auscultation to be performed in all ‘low risk pregnancies’, with continuous EFM in those pregnancies who deemed to be ‘high risk’.
• Fetal macrosomia: maternal concern about fetal size is a common problem that frequently lead to anxiety among obstetricians and midwives. Unfortunately both clinical and ultrasound estimation of fetal size are prone to inaccuracy and unnecessary inductions of labor and caesarean sections are performed as a consequence.
• Maternal request: the request for delivery by an elective C/S where there is not a compelling obstetric indication is becoming more common. The effect of maternal request on C/S rates range from 2-28% in the contribution as a primary reason. There is a need for national debate on whether maternal choice is a valid indication for C/S.
Indications for caesarean section:
The four major indications accounting for more than 70% of operations are:
• Previous caesarean section.
• Dystocia.
• Malpresentation.
• Suspected acute fetal compromise.
• Other indications, such as multifetal pregnancy, abruptio placenta, placenta previa, fetal disease and maternal disease are less common.
Procedure:
• Informed consent must always be obtained prior to operation. Where there is incapacity to consent as may occur with conditions such as eclampsia, the doctor is expected to act in patient’s best interest.• The bladder should be emptied before the procedure.
• Skin incision can be done using Pfannenstiel incision were skin and subcutaneous tissue are incised using a transverse curvilinear incision 2 fingerbreadths above the symphysis pubis extending from and to points lateral to the lateral margin of the abdominal rectus muscle. This incision has the advantage of improved cosmetic results, decreased analgesic requirements and superior wound strength.
Or the skin may be incised using a vertical infraumbilical incision which is indicated in cases of extreme maternal obesity, suspicion of other intra-abdominal pathology necessitating surgical intervention, or where access to the uterine fundus may be required (classical C/S).
The incision extends from the lower border of the umbilicus to the symphysis pubis and may be extended to the xiphisternum. The vertical incision provides greater ease of access to the pelvic and intra-abdominal organs and may be enlarged more easily, however, the incidence of wound dehiscence is increased.
4-UTERINE INCISION
• A lower uterine segment incision is used in over 95% of C/S due to ease of repair, reduced blood loss and low incidence of dehiscence or rupture in subsequent pregnancies.• There are relatively few absolute indications for classical section which incorporates the upper uterine segment. These include:
• A lower uterine segment containing fibroids.
• A lower segment covered with dense adhesions, both of which(1+2) may make entry difficult.
• Placenta previa.
• Transverse lie with the back down.
• Fetal abnormality e.g. conjoined twins.
• C/S in the presence of carcinoma of the cervix so as to avoid damage to the cervix and its vascular and lymphatic supply.
Once the uterus is incised, the membranes are ruptured if still intact then the fetus is delivered after which 5 IU oxytocin IV administered to aid uterine contraction and placental separation then the placenta is delivered by cord traction.
Closure of the uterus should be performed in either single or double layers with continuous or interrupted sutures.
Abdominal closure is performed in the anatomical planes.
Complications:
Confidential inquiries of maternal deaths have enabled the risks associated with different methods of delivery to be analyzed, case fatality rate for all C/S is 5 times that for vaginal delivery, although for elective C/S the difference does not reach statistical significance.A. Intraoperative complication:
• Bowel damage may occur during a repeated procedure or if adhesions are present from previous surgery.
• Placenta previa: the proportion of patients with placenta previa increases almost linearly after each previous C/S.
• Hemorrhage: it may be a consequence of damage to the uterine vessels or may be incidental as a consequence of uterine atony or placenta previa.
• Urinary tract damage: the risk of bladder injury after prolonged labor where the bladder is displaced caudally, and after previous C/S where scarring obliterates the vesicouterine space, or where a vertical extension to the uterine incision has occurred. Damage to the ureter is uncommon as reflection of the bladder displaces them roastrally.
• Caesarean hysterectomy: the most common indication for it is uncontrollable hemorrhage requiring immediate treatment which occur in 1/1000 deliveries. The most important risk factor for emergency postpartum hysterectomy is previous C/S especially when the placenta overlies the old scar increasing the risk for accreta. Other indications for hysterectomy are atony, uterine rupture, extension of a transverse uterine incision and fibroids preventing uterine closure and hemostasis.
B. Postoperative complications:
• Infection and endometritis: women undergoing C/S have 5-20 fold greater risk of an infectious complication when compared with vaginal delivery. Complications include fever, wound infection, endometritis, bacteremia and UTI. Other common causes of postoperative fever include hematoma, atelactasis and deep vein thrombosis.
• Careful surgical technique, skin antisepsis, prophylactic antibiotics should be administered to reduce the incidence of postoperative endometritis.
• 2. Pulmonary emboli and DVT: deaths from pulmonary embolism remain the leading direct cause of maternal death, and C/S is a major risk factor. The incidence is reduced by perioperative administration of prophylactic heparin and the prompt initiation of treatment where required.
• 3. Psychological complication: all difficult deliveries carries increased maternal psychological and physical morbidity, the compromised postpartum psychological functioning in women delivered by C/S may be secondary to delayed contact with the baby.
Repeat C/S:
In many units C/S rates for primigravida of 24% are seen. Consequently the problem of management of a woman with scarred uterus in subsequent pregnancy is a common antenatal problem. Up to 70% of women with previous C/S can achieve a vaginal delivery. Patient’s choice can not and should not be ignored in decisions regarding management, and it is important to discuss the risks and benefits of elective C/S as compared to trial of vaginal delivery.From a maternal perspective, elective C/S avoid labor with its risk of perineal trauma, the need to undergo emergency C/S and scar dehiscence/rupture with subsequent morbidity and mortality. The risk of uterine rupture following trial of labor compared with women undergoing elective C/S is lower than 1%.
However, elective C/S carries maternal risks which include increased bleeding, thromboembolism, febrile morbidity, prolonged recovery, long term bladder dysfunction and increased risks of placenta previa in subsequent pregnancies.
From a fetal perspective, an elective C/S reduces the risks of scar rupture, but increases the risk of transient tachypnea/respiratory distress syndrome.