Technique Of Cesarean Section: What is scientific? What is unscientific? (Evidence based answers)

 Introduction:

            Cesarean section has become the most commonly performed surgery in obstetric practice. When any procedure or technique or for that matter any drug is widely used, it is natural to look at the data to know how rational is our thinking and where has irrationality crept into our thought processes. As students of science, we seek to remain on the scientific course at all times. Therefore evidence becomes very critical for us. Undoubtedly, evidence is provided by data. Hans Rosling in his famous book Factfullness states that when in doubt look at the data. We are going to look at the data for nearly every step that we follow while performing a cesarean section and accordingly conclude. Agreed, it is impossible to cover each and every micro-aspect of the techniques involved in the surgery. However, care has been taken to include all wherein good quality data was available. Nearly all data has been generated from Randomised Control Trials (RCTs) so the quality of conclusions is sterling. It is possible that our thinking may be completely changed in some steps and the others may be reinforced. That is precisely the aim of writing this chapter.

Anesthesia:

Spinal Anesthesia or General Anesthesia?

Both regional and general anesthesia may be employed for cesarean section. Each is relatively safe and they have their advantages and disadvantages. The actual decision to adopt one technique over another depends on the maternal and fetal status and the skill and ability of the anesthesiologist to tackle the situation with the aim of patient and baby safely. Among these, many of the cases come to the hospital on an emergency basis. The anaesthesiologists have to face the challenge of providing anesthesia for emergency cesarean section, being the last member of the perinatal team. The challenge faces the risks of involvement of maternal changes in pregnancy, the presence of fetal distress, and various anesthetic complications arising in the perioperative period. Still, now anesthetic mishaps are considered the sixth most frequent cause of maternal mortality. The use of regional Anesthesia reduced the number of deaths by about 80% but deaths involving general anesthesia have not decreased and the incidence is 17 times more than the regional anesthesia. Most of the deaths or complications are related to airway management (also failed intubation) ¹.           

Spinal Anesthesia or Epidural?

            Both spinal and epidural techniques are shown to provide effective anesthesia for cesarean sections. Both techniques are associated with moderate degrees of maternal satisfaction. Spinal anesthesia has a shorter onset time, but treatment for hypotension is more likely if spinal anesthesia is used. No conclusions can be drawn about intraoperative side‐effects and postoperative complications because they were of low incidence and/or not reported ².

How to minimize nausea and vomiting during cesarean section

            Many agents and techniques have been tried. The spectrum is large. 5-HT3 antagonists, dopamine antagonists, corticosteroids (steroids), antihistamines, sedatives, opioid antagonists, acupressure, ginger, and the like. Of these, on basis of RCT-based evidence, 5-HT3 antagonists, dopamine antagonists, corticosteroids, sedatives, and acupressure have efficacy in reducing nausea and vomiting in women undergoing regional anesthesia for cesarean section ³.

How to scientifically prevent hypotension during anesthesia at cesarean section?

Hypotension during spinal anesthesia at cesarean section is always very closely watched for and aggressively handled at cesarean section. The changing of position from the side for administering spinal anesthesia to supine for performing the surgery worsens the hypotension intrinsically associated with spinal anesthesia. In the cesarean section, the component of postural hypotension on change of position gets added. The efforts are currently focused on scientifically preventing hypotension. 125 studies involving 9469 women were reviewed to identify evidence-based interventions to prevent maternal hypotension following spinal anesthesia ⁴. Interesting data emerged.

Crystalloid versus control (no fluids)

Fewer women experienced hypotension in the crystalloid group compared with no fluids. There was no clear difference between groups in numbers of women with nausea and vomiting. No baby had an Apgar score of less than 8 at five minutes in either group (60 babies, low-quality evidence.

Colloid versus crystalloid

Fewer women experienced hypotension in the colloid group compared with the crystalloid group. There were no differences between groups for maternal bradycardia requiring intervention, nausea and/or vomiting, or an Apgar score of less than 8 at five minutes.

Ephedrine versus phenylephrine

There were no differences between ephedrine and phenylephrine groups for preventing maternal hypotension.

Ondansetron versus control

Ondansetron administration was more effective than control (placebo saline) for preventing hypotension requiring treatment

From this, it appears that while interventions such as crystalloids, colloids, ephedrine, phenylephrine, ondansetron, or lower leg compression can reduce the incidence of hypotension, none have been shown to prevent maternal hypotension completely at cesarean section. There will still be some women who will have hypotension and will need to get treated ⁴.

Supplemental oxygen for cesarean section during regional anesthesia:

            It is a common practice to supplement oxygen in the administration of regional anesthesia for cesarean section. It is a very old treatment and worth reviewing through a glass of scientific evidence. Surprisingly no convincing evidence was found to unequivocally state that giving supplementary oxygen to healthy term pregnant women during elective cesarean section under regional anesthesia is beneficial. Data also can't say if this habit is harmful to either the mother or the fetus' short-term clinical outcome as assessed by Apgar scores. Although there were significantly higher maternal and neonatal blood gas values and markers of free radicals when extra oxygen was given, how beneficial were the effects of this habit remains unanswered ⁵. Based on this data it seems that the clinicians should continue to do whatever they are currently doing. They need not change their policy.

Interventions at cesarean section for reducing the risk of aspiration pneumonitis:

            Aspiration pneumonitis is a dreaded complication, especially during general anesthesia. It is a syndrome resulting from the inhalation of gastric contents. The incidence of obstetric anesthesia has fallen, largely due to improved anesthetic techniques and the increased use of regional anesthesia for cesarean section. Set-ups, where emergency cesarean sections have to be performed in subjects not prepared preoperatively for anesthesia, are a reality occasionally encountered. Many techniques and medications are promoted for preventing this complication. It is time to examine the evidence regarding the efficacy of these measures. Evidence shows that when compared with no treatment or placebo, there was a significant reduction in the risk of intragastric pH < 2.5 with antacids and proton pump antagonists. H2 antagonists were associated with a reduced risk of intragastric pH < 2.5 at intubation when compared with proton pump antagonists. The combined use of 'antacids plus H2 antagonists' was associated with a significant reduction in the risk of intragastric pH < 2.5 at intubation when compared with placebo ⁶.

Local anesthetic wound infiltration during the cesarean section for postoperative pain relief

            Many obstetricians have the habit of infiltrating local anesthetic agents at the abdominal wound site for postoperative pain relief. Many anesthetists too encourage this technique. Interesting evidence based on twenty studies wherein 1150 women were included has shown that women who had cesarean section performed under regional analgesia and had wound infiltration had a decrease in opioid analgesic consumption at 24 hours compared to placebo. In women under general anesthesia, with cesarean section wound infiltration and peritoneal spraying with a local anesthetic, the need for opioid rescue was reduced. The numerical pain score (0 to10) within the first hour was also reduced. Women who had regional analgesia with abdominal nerves blocked had decreased opioid consumption. However, the addition of ketamine or opioid analgesic to the local analgesic does not confer any advantage ⁷.

            There are some other drugs, techniques, and procedures done in obstetric anesthesia, besides those examined above, for cesarean section. However, they are not mentioned here as good quality RCT-based data is not available for them, as yet.

Maternal position during cesarean section:

Much has been written about, postulated, and tried as regards the maternal position during cesarean section. During a cesarean, section mothers can be in different positions. Theatre tables could be tilted laterally, upwards, downwards, or flexed and wedges or cushions could be used. These are attempts to minimize or prevent maternal and neonatal complications altogether. RCTs studying this aspect have thrown some very important light on this matter ⁸.

·      The incidence of air embolism was not affected by head up versus horizontal position, right lateral tilt, right lumbar pelvic wedge, and head down tilt with horizontal positions.

·       No change was found in hypotensive episodes when comparing full lateral tilt with 15-degree tilt. Hypotensive episodes were decreased with manual displacers and increased with a right lumbar wedge compared with a right pelvic wedge and increased with a right lateral tilt compared with a left lateral tilt.

·       The position did not affect systolic blood pressure when comparing left lateral tilt or head down tilt with horizontal positions, or full lateral tilt with 15-degree tilt. Manual displacers showed decreased fall in mean systolic blood pressure compared with left lateral tilt

·       The position did not affect diastolic blood pressures when comparing left lateral tilt versus horizontal positions) when compared with horizontal positions. There were no statistically significant changes in maternal pulse rate, five-minute Apgar, maternal blood pH, or cord blood pH when comparing different positions.

It seems from the above results that manual displacers offer some advantage over different positions in minimizing some complications during cesarean sections.

Preparation of parts with antiseptics before cesarean section

Cleansing the vagina with an antiseptic solution before a cesarean delivery:

21 trials were included to generate good quality evidence for this. In total, the reporting results were for 7038 women evaluating the effects of vaginal cleansing (17 using povidone-iodine, 3chlorhexidine, and 1 benzalkonium chloride) on post-cesarean infectious morbidity. Trials used vaginal preparations administered by sponge sticks, douches, or soaked gauze wipes. The control groups were typically no vaginal preparation (17 trials) or the use of a saline vaginal preparation (4 trials). Results showed that vaginal preparation with an antiseptic solution immediately before cesarean delivery reduces the incidence of post-cesarean endometritis from 7.1% in control groups to 3.1% in vaginal cleansing groups. This reduction in endometritis was seen for both iodine-based solutions and chlorhexidine-based solutions. Risks of postoperative fever and postoperative wound infection are also probably reduced by vaginal antiseptic preparation. Two trials found that there may be a lower risk of a composite outcome of wound complication or endometritis in women receiving preoperative vaginal preparation. No adverse effects were reported with either the povidone-iodine or chlorhexidine vaginal cleansing ⁹.

 

From the analysis of this evidence, it seems that vaginal preparation with povidone-iodine or chlorhexidine solution compared to saline or not cleansing immediately before cesarean delivery reduces the risk of post-cesarean endometritis, postoperative fever, and postoperative wound infection.

Skin preparation for preventing infection following cesarean section

In this, the effects of different antiseptic agents, different methods of application, or different forms of antiseptic used for preoperative skin preparation for preventing post-cesarean infection were analyzed to draw evidence-based conclusions.

Antiseptic Agents ¹⁰:

Parachlorometaxylenol with iodine versus iodine alone

Evidence is uncertain whether parachlorometaxylenol with iodine made any difference in the incidence of surgical site infection

Chlorhexidine gluconate versus povidone-iodine

Chlorhexidine gluconate, when compared with povidone-iodine, probably reduces the incidence of surgical site infection more than povidone-iodine. However, chlorhexidine gluconate, when compared with povidone-iodine, made no real difference in the incidence of postoperative endometritis.

It, therefore, seems that no clear evidence emerges as to what sort of skin preparation may be most effective for preventing post-cesarean surgical site infection, or for reducing other undesirable outcomes for mother and baby. Therefore the clinicians need not change their current policy in this matter.

Opening the abdomen

Abdominal surgical incisions for cesarean section

            The evidence to conclude this matter is based on two studies that compared the Joel-Cohen incision with the Pfannenstiel incision. Overall, there was a 65% reduction in reported postoperative febrile morbidity with the Joel-Cohen incision. One of the trials reported reduced postoperative analgesic requirements; operating time; delivery time; total dose of analgesia in the first 24 hours; estimated blood loss; postoperative hospital stay for the mother; and increased time to the first dose of analgesia compared with the Pfannenstiel group. No other significant differences were found in either trial ¹¹.

In an earlier study by this team, Joel-Cohen incision when compared with Pfannenstiel incision was associated with ¹²:

·       Less blood loss,

·       Shorter operating time

·       Postoperatively, reduced time to oral intake

·       Less fever

·       Shorter duration of postoperative pain

·       Fewer analgesic injections

·       Shorter time from skin incision to the birth of the baby

            It can therefore be said that the Joel-Cohen incision has advantages compared with the Pfannenstiel incision and is better in the above-identified ways.

Scalpel versus electrosurgery for abdominal incision

            The certainty of the evidence was moderate to very low due to imprecise results. Low-certainty evidence showed no clear difference in wound infection between the scalpel and electrosurgery. It, therefore, seems that there is a need for more research to determine the relative effectiveness of scalpel compared with electrosurgery for major abdominal incisions ¹³.

Intraoperative features:

Tranexamic Acid in reducing intraoperative blood loss:

            Tranexamic acid as a hemostatic agent has been used for many years now. For the last few years, its role as a prophylactic agent to minimize blood loss has also come into focus. Through an RCT it was recently well documented that tranexamic acid can be safely used as a prophylactic agent to reduce bleeding during elective and emergency LSCS. Tranexamic acid (10 mg/Kg) was given in 100 ml normal saline 10 minutes before skin incision to women in the study group. There was a significant decrease in intraoperative bleeding in women receiving tranexamic acid. Women in the control group had a significant fall in postoperative hemoglobin when compared to women who received tranexamic acid. Also, women who received tranexamic acid did not develop any significant hemodynamic changes during or immediately after the surgery ¹⁴.

Surgical techniques involving the uterus at cesarean section

            Approach to the uterus including its opening and closure at cesarean section should include attention to not only the duration of the surgical procedure and maternal blood loss but also maternal postoperative pain, continuing blood loss, and development of anemia, fever, and wound infection. Additional complications can include problems with breastfeeding, passing urine, longer-term fertility problems, complications in future pregnancies (uterine rupture), or increased risks associated with future surgery. The review authors searched the medical literature for randomized controlled trials to inform the most appropriate surgical techniques to use ¹⁵.

            A very nicely done review studied twenty-seven trials involving 17,808 women from several different countries contributed to the review. Results from 18 randomized trials contributed to reports that single layer closure of the uterine incision was associated with a reduction in blood loss, and duration of the procedure ¹⁵.

Five trials compared blunt with sharp dissection at the time of the uterine incision (2141 women) and a further two trials auto-suture devices with standard hysterectomy (300 women). Blunt surgery was associated with a reduction in mean blood loss at the time of the procedure. The use of an auto-suture instrument did not reduce procedural blood loss but increased the duration of the procedure.

These authors found a single trial comparing chromic catgut with polyglactin-910, involving 9544 women reported that catgut closure versus closure with polyglactin was associated with a significant reduction in the need for blood transfusion.

They report nineteen studies were identified comparing single layer with double layer closure of the uterus, with data contributed to the meta-analyses from 14 studies. There were no statistically significant differences identified for the primary outcome, febrile morbidity.

Although the meta-analysis suggested single layer closure was associated with a reduction in mean blood loss, heterogeneity is high and this limits the clinical applicability of the result. There were no differences identified in the risk of blood transfusion or other reported clinical outcomes.

For the comparison, blunt versus sharp dissection when performing the uterine incision, there is no additional evidence from one study to suggest a significant reduction in the need for blood transfusion with blunt extension.

Based on this review and the evidence so generated the reviewers recommended that a cesarean section is a common procedure performed on women worldwide. There is increasing evidence that for many techniques, short-term maternal outcomes are equivalent. Until long-term health effects are known, surgeons should continue to use the techniques they prefer and currently use ¹⁵.

Methods of delivering the placenta at cesarean section

The dilemma here is should the placenta be manually or actively delivered and the uterine suturing commenced early to prevent blood loss? In one review of 15 studies (4694 women), manual removal of the placenta was associated with more endometritis; more blood loss > 1000 ml; lower hematocrit after delivery (%); greater hematocrit fall after delivery (%); longer duration of hospital stay (days). Delivery of the placenta with cord traction at cesarean section has more advantages compared to manual removal. These are less endometritis; less blood loss; less decrease in hematocrit levels postoperatively; and shorter duration of hospital stay ¹⁶.

Extra‐abdominal versus intra‐abdominal repair of the uterine incision

            There are many obstetricians who routinely prefer to eventerate the uterus for suturing. The advantages quoted are better visualization and more space. However on the superiority of eventeration or otherwise good data is sorely lacking. A very old study of 2004 concluded that there is no evidence from this review to make definitive conclusions about which method of uterine closure offers greater advantages, if any. However, the authors remained vague and stated that these results are based on too few and too small studies to detect differences in rare, but severe, complications ¹⁷.

Mechanical dilatation of the cervix during elective cesarean section

            It is very conventional teaching in medical colleges that one must invariably digitally dilate the cervix while performing an elective cesarean section as this subject is not likely to be in labor. As a result, her cervix is not dilated and so there could be difficulty in drainage of the lochia. A syndrome called Trapped Lochia Syndrome has also been described to occur if the cervix is not dilated manually from above. This thinking needed a review. It was found on examining the evidence that at this time, the evidence does not support or refute the use of mechanical dilatation of the cervix during the elective cesarean section for reducing postoperative morbidity ¹⁸. On basis of this review, it can be concluded that the clinician need not change the policy adopted by him or her in this matter.

Closure versus non‐closure of the peritoneum at cesarean section

            A big debate was generated decades ago when a group of obstetricians from Israel proposed that there was no need to close the peritoneum during cesarean section. Till then layers were meticulously closed. A big review was undertaken to find an answer to the question should whether the peritoneum is sutured or not. A total of 21 trials (17,276 women) provided data that could be included in an analysis ¹⁹.

·       Non-closure of visceral and parietal peritoneum versus closure of both parietal layers

Postoperative adhesion formation was assessed in only four trials with 282 women, and no difference was found between groups. The duration of hospital stay in a total of 13 trials involving 14,906 women, was also reduced. In a trial involving 112 women, reduced chronic pelvic pain was found in the peritoneal non-closure group.

·       Non-closure of visceral peritoneum only versus closure of both peritoneal surfaces

There was a reduction in operative time, postoperative days in the hospital, and wound infection. There was no significant reduction in postoperative pyrexia.

·       Non-closure of parietal peritoneum only versus closure of both peritoneal layers

There was a reduction inoperative time and postoperative pain with no difference in the incidence of postoperative pyrexia, endometritis, postoperative duration of hospital stay, and wound infection

From this evidence, one can conclude that there was surely a reduction in operative time across all the subgroups. There was also a reduction in the period of hospitalization post-cesarean section except in the subgroup where the parietal peritoneum only was not sutured and where there was no difference in the period of hospitalization. The evidence on adhesion formation was limited and inconsistent. Therefore there is currently insufficient evidence of benefit to justify the additional time and use of suture material necessary for peritoneal closure.

Techniques and materials for skin closure in cesarean section

            It is well known that in cesarean sections, the skin incision is re-approximated by a subcuticular suture immediately below the skin layer or by an interrupted suture, or by staples and other techniques. A great variety of materials and techniques are used for skin closure after a cesarean section and there is a need to examine the data to get evidence that can provide the best outcomes for women. The two methods of skin closure for cesarean that has been most often compared are non-absorbable staples and absorbable subcutaneous sutures. In a review, it was found that compared with absorbable subcutaneous sutures, non-absorbable staples are associated with similar incidences of wound infection ²⁰.

Other important secondary outcomes, such as wound complications, were also similar between the groups in women with Pfannenstiel incisions. However, it is important to note, that for both of these outcomes (wound infection and wound complication), and staples may have a differential effect depending on the type of skin incision, i.e., Pfannenstiel or vertical. Compared with absorbable subcutaneous sutures, non-absorbable staples are associated with an increased risk of skin separation, and therefore, reclosure. However, skin separation was variably defined across trials, and most staples were removed before four days postpartum ²⁰.

            One can therefore, based on this evidence can filter down the deduction that there is currently no conclusive evidence about how the skin should be closed after a cesarean section. Staples are associated with similar outcomes in terms of wound infection, pain, and cosmesis compared with sutures, and these two are the most commonly studied methods for skin closure after cesarean section. If staples are removed on day three, there is an increased incidence of skin separation and the need for reclosure compared with absorbable sutures ²⁰.

            However, in 2020 another review specifically examined subcuticular sutures for skin closure in non‐obstetric surgery. This evidence to a large extent can also be applied to cesarean sections. It was found that there is no clear difference in the incidence of surgical site infection for subcuticular sutures in comparison with any other skin closure methods. Subcuticular sutures probably reduce wound complications compared with staples, and probably improve patient satisfaction compared with transdermal sutures or staples. However, tissue adhesives may improve patient satisfaction compared with subcuticular sutures, and transdermal sutures and skin staples may be quicker to apply than subcuticular sutures ²¹.

Intraoperative interventions for preventing postoperative surgical site infection in cesarean section

            Understandably, surgical site infection remains a big area of focus for all operating surgeons. This is more so in cesarean sections where many times the procedure is unplanned and so the susceptibility of infection of the surgical site is more. Some intraoperative interventions have been found to have a basis of good quality evidence so worth adopting if not already adopted. If adopted then there is good reason to continue these practices on basis of a good quality review. Data were extracted in this review from 30 reviews which had 349 included trials, totaling 73,053 participants. There is high- or moderate-certainty evidence for the following outcomes for these intraoperative interventions ²². This overview provides the most up-to-date evidence on the use of intraoperative treatments for the prevention of surgical site infections from all currently published Cochrane Reviews.

(1) Prophylactic intravenous antibiotics administered before cesarean incision reduce surgical site infection risk compared with administration after cord clamping.

(2) Antibiotic prophylaxis reduces surgical site infection risk in cesarean sections compared with no antibiotics.

Timing of intravenous prophylactic antibiotics for preventing postpartum infectious morbidity in women undergoing cesarean delivery

            Much has been written regarding when and how to give prophylactic antibiotics during a cesarean section. One review addressed this question and brought out some clear data ²³. Based on high-quality evidence, intravenous prophylactic antibiotics for cesarean administered preoperatively significantly decreases the incidence of composite maternal postpartum infectious morbidity as compared with administration after cord clamp. There were no differences in adverse neonatal outcomes reported. It is therefore scientific to recommend that women undergoing cesarean delivery should receive antibiotic prophylaxis preoperatively to reduce maternal infectious morbidities.

To catheterize or not to catheterize?

            Many obstetricians prefer to routinely intraoperatively catheterize during cesarean sections and in most instances, an indwelling catheter is used. How scientific is this habit is wondered by many who seek evidence for or against this habit? An exhaustive review of this matter brought out many interesting facts ²⁴:

·       Indwelling bladder catheterization was associated with a reduced incidence of bladder distension at the end of the operation and fewer cases of retention of urine. In contrast, indwelling bladder catheterization was associated with a longer time to first void and more pain or discomfort due to catheterization (and/or at first voiding).

·       Similarly, compared to women in the 'no catheter' group, indwelling bladder catheterization was associated with a longer time to ambulation and a longer stay in hospital. There was no difference in postpartum hemorrhage (PPH) due to uterine atony. There was also no difference in the incidence of UTI (as defined by trialists) between the indwelling bladder catheterization and no catheterization groups.

·       There was no difference in postpartum hemorrhage (PPH) due to uterine atony. There was also no difference in the incidence of UTI (as defined by trialists) between the indwelling bladder catheterization and no catheterization groups.

So evidence shows that intraoperative indwelling catheterization is not a very helpful habit and clinicians who are wedded to it can safely let this habit go.

Chewing gum for enhancing early recovery of bowel function after cesarean section

            When this concept first got floated it caused more amusement than anything else. But soon many institutions adopted this as a policy in cesarean section subjects which were performed in regional blocks. A review examines the scientific validity of this practice. This review found 17 randomized controlled trials (involving 3149 women). The available evidence suggests that gum chewing in the immediate postoperative period after a CS is a well-tolerated intervention that enhances early recovery of bowel function ²⁵.

Epilogue:

            Cesarean section is like the mother in a family. She runs the family, manages the household, does well for every member of the family, and still is criticized the most. So is cesarean section – it has saved countless lives of both, the mother as well as the newborn. Still, it is continuously criticized and scrutinized. Being so much of utility, it is but natural that the scientific community and investigators like to closely examine all aspects related to cesarean section very closely, periodically, and at times repeatedly. Right from the preparation of the patient to anesthesia techniques, intraoperative steps that are popularly used, and right up to postoperative care so many aspects related to this surgery have been closely examined in this chapter. The continuous focus has been on the extraction of evidence-based quality data. This chapter can likely have long-term effects on certain habits, routines, and techniques used at cesarean sections by interested readers. If even one decision of any reader could be made more scientific, the efforts that have gone into this chapter were worth it.

References

1.  Haque MF, Sen S, Meftahuzzaman SM, Haque MM. Anesthesia for emergency cesarean section. Mymensingh Med J. 2008 Jul; 17(2):221-6.
2. Ng KW, Parsons J, Cyna AM, Middleton P. Spinal versus epidural anaesthesia for caesarean section. Cochrane Database of Systematic Reviews 2004, Issue 2.
3. Griffiths JD, Gyte GML, Popham PA, Williams K, Paranjothy S, Broughton HK, Brown HC, Thomas J. Interventions for preventing nausea and vomiting in women undergoing regional anaesthesia for caesarean section. Cochrane Database of Systematic Reviews 2021, Issue 5.
4.  Chooi C, Cox JJ, Lumb RS, Middleton P, Chemali M, Emmett RS, Simmons SW, Cyna AM. Techniques for preventing hypotension during spinal anaesthesia for caesarean section. Cochrane Database of Systematic Reviews 2020, Issue 7.
5. Chatmongkolchart S, Prathep S. Supplemental oxygen for caesarean section during regional anaesthesia. Cochrane Database of Systematic Reviews 2016, Issue 3
6. Paranjothy S, Griffiths JD, Broughton HK, Gyte GML, Brown HC, Thomas J. Interventions at caesarean section for reducing the risk of aspiration pneumonitis. Cochrane Database of Systematic Reviews 2014, Issue 2.
7. Bamigboye AA, Hofmeyr GJ. Local anaesthetic wound infiltration and abdominal nerves block during caesarean section for postoperative pain relief. Cochrane Database of Systematic Reviews 2009, Issue 3.
8.  Cluver C, Novikova N, Hofmeyr GJ, Hall DR. Maternal position during caesarean section for preventing maternal and neonatal complications. Cochrane Database of Systematic Reviews 2013, Issue 3.
9. Haas DM, Morgan S, Contreras K, Kimball S. Vaginal preparation with antiseptic solution before cesarean section for preventing postoperative infections. Cochrane Database of Systematic Reviews 2020, Issue 4.
10. Hadiati DR, Hakimi M, Nurdiati DS, Masuzawa Y, da Silva Lopes K, Ota E. Skin preparation for preventing infection following caesarean section. Cochrane Database of Systematic Reviews 2020, Issue 6.
11. Mathai M, Hofmeyr GJ, Mathai NE. Abdominal surgical incisions for caesarean section. Cochrane Database of Systematic Reviews 2013, Issue 5.
12. Hofmeyr GJ, Mathai M, Shah AN, Novikova N. Techniques for caesarean section. Cochrane Database of Systematic Reviews 2008, Issue 1
13. Charoenkwan K, Iheozor‐Ejiofor Z, Rerkasem K, Matovinovic E. Scalpel versus electrosurgery for major abdominal incisions. Cochrane Database of Systematic Reviews 2017, Issue 6
14. Hemapriya L, More G, Kumar A. Efficacy of Tranexamic Acid in Reducing Blood Loss in Lower Segment Cesearean Section: A Randomised Controlled Study. J Obstet Gynaecol India. 2020 Dec; 70(6):479-484.
15. Dodd JM, Anderson ER, Gates S, Grivell RM. Surgical techniques for uterine incision and uterine closure at the time of caesarean section. Cochrane Database of Systematic Reviews 2014, Issue 7
16. Anorlu RI, Maholwana B, Hofmeyr GJ. Methods of delivering the placenta at caesarean section. Cochrane Database of Systematic Reviews 2008, Issue 3.
17. Jacobs‐Jokhan D, Hofmeyr GJ. Extra‐abdominal versus intra‐abdominal repair of the uterine incision at caesarean section. Cochrane Database of Systematic Reviews 2004, Issue 4.
18. Liabsuetrakul T, Peeyananjarassri K. Mechanical dilatation of the cervix during elective caesarean section before the onset of labour for reducing postoperative morbidity. Cochrane Database of Systematic Reviews 2018, Issue 8.
19. Bamigboye AA, Hofmeyr GJ. Closure versus non‐closure of the peritoneum at caesarean section: short‐ and long‐term outcomes. Cochrane Database of Systematic Reviews 2014, Issue 8
20. Mackeen AD, Berghella V, Larsen ML. Techniques and materials for skin closure in caesarean section. Cochrane Database of Systematic Reviews 2012, Issue 11.
21. Goto S, Sakamoto T, Ganeko R, Hida K, Furukawa TA, Sakai Y. Subcuticular sutures for skin closure in non‐obstetric surgery. Cochrane Database of Systematic Reviews 2020, Issue 4.
22. Liu Z, Dumville JC, Norman G, Westby MJ, Blazeby J, McFarlane E, Welton NJ, O'Connor L, Cawthorne J, George RP, Crosbie EJ, Rithalia AD, Cheng HY. Intraoperative interventions for preventing surgical site infection: an overview of Cochrane Reviews. Cochrane Database of Systematic Reviews 2018, Issue 2
23. Mackeen AD, Packard RE, Ota E, Berghella V, Baxter JK. Timing of intravenous prophylactic antibiotics for preventing postpartum infectious morbidity in women undergoing cesarean delivery. Cochrane Database of Systematic Reviews 2014, Issue 12.
24. Abdel‐Aleem H, Aboelnasr MF, Jayousi TM, Habib FA. Indwelling bladder catheterisation as part of intraoperative and postoperative care for caesarean section. Cochrane Database of Systematic Reviews 2014, Issue 4.
25. Pereira Gomes Morais E, Riera R, Porfírio GJM, Macedo CR, Sarmento Vasconcelos V, de Souza Pedrosa A, Torloni MR. Chewing gum for enhancing early recovery of bowel function after caesarean section. Cochrane Database of Systematic Reviews 2016, Issue 10.