The CORONIS Trial. International study of caesarean section surgical techniques: a randomised fractional, factorial trial

Comparison between extraperitoneal and transperitoneal cesarean section: Retrospective case-control study

INTRODUCTION

  The main advantage of extraperitoneal cesarean section (EXPCS) is not only less pain, faster recovery, and less potential for infection but also a possible lack of intraperitoneal adhesions.

METHODS

  In a 3-year period from 2019 to 2022, 88 EXPCSs were performed. A comparison was made with 90 patients who underwent a standard transperitoneal cesarean section (TPCS). For both groups, the inclusion criterion was uterine inertia and prolonged labor as an indication for cesarean section. Only pregnant women from 37 to 42 weeks were included. After this, 51 patients remained in the EXPCS arm, and 49 remained in the TPCS arm.

RESULTS

  No statistical difference was found in gestational weeks, newborn weight, Apgar score, erythrocyte (Er), hemoglobin (Hgb), and hematocrit (Htc) values and duration of operative time between the EXPCS and TPCS groups. Leukocytes, C-reactive protein (CRP) with fever higher than >38°C on the third postoperative day were found statistically significantly (p=0.005) higher in the TPCS group. The usage of tramadol + metamizole at 3, 6, and 9 hours after delivery and diclofenac at 6, 12, and 18 hours after surgery was statistically significantly (p<0.05) higher in the TPCS group. On the visual analog scale (VAS) 24 hours after surgery, a statistically significant difference was found (p = 0.001) between the two groups. In the small group of patients who underwent a TPCS section after an EXPCS, intraperitoneal adhesions were not found; in another group of patients who underwent a TPCS twice, adhesions were found in 12 patients; Fisher's exact test (p=0.04).

CONCLUSION

  The protective effect of EXPCS for infection could be proven in prolonged delivery. EXPCS could be a good solution in the fight against adhesions and infection in women who undergo second, third, or even fourth cesarean sections.

Evidence-based surgical procedures to optimize caesarean outcomes: an overview of systematic reviews

Background

Caesarean section (CS) is the most performed major surgery worldwide. Surgical techniques used for CS vary widely and there is no internationally accepted standardization. We conducted an overview of systematic reviews (SR) of randomized controlled trials (RCT) to summarize the evidence on surgical techniques or procedures related to CS.

Methods

Searches were conducted from database inception to 31 January 2024 in Cochrane Database of Systematic Reviews, PubMed, EMBASE, Lilacs and CINAHL without date or language restrictions. AMSTAR 2 and GRADE were used to assess the methodological quality of the SRs and the certainty of evidence at outcome level, respectively. We classified each procedure-outcome pair into one of eight categories according to effect estimates and certainty of evidence. The overview was registered at PROSPERO (CRD 42023208306).

Findings

The analysis included 38 SRs (16 Cochrane and 22 non-Cochrane) published between 2004-2024 involving 628 RCT with a total of 190,349 participants. Most reviews were of low or critically low quality (AMSTAR 2). The SRs presented 345 procedure-outcome comparisons (237 procedure versus procedure, 108 procedure versus no treatment/placebo). There was insufficient or inconclusive evidence for 256 comparisons, clear evidence of benefit for 40, possible benefit for 17, no difference of effect for 13, clear evidence of harm for 14, and possible harm for 5. We found no SRs for 7 pre-defined procedures. Skin cleansing with chlorhexidine, Joel-Cohen-based abdominal incision, uterine incision with blunt dissection and cephalad-caudal expansion, cord traction for placental extraction, manual cervical dilatation in pre-labour CS, changing gloves, chromic catgut suture for uterine closure, non-closure of the peritoneum, closure of subcutaneous tissue, and negative pressure wound therapy are procedures associated with benefits for relevant outcomes.

Interpretation

Current evidence suggests that several CS surgical procedures improve outcomes but also reveals a lack of or inconclusive evidence for many commonly used procedures. There is an urgent need for evidence-based guidelines standardizing techniques for CS, and trials to fill existing knowledge gaps.

Funding

UNDP-UNFPA-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), a cosponsored programme executed by the World Health Organization (WHO).

Intra-operative Guidelines for the Prevention of Uterine Niche Formation in Cesarean Sections: A Review

Formation of a uterine niche following a C-section can predispose the patient to future obstetric complications such as dehiscence, uterine rupture, ectopic pregnancy, and placenta accreta. The significant morbidity and mortality of these complications along with increasing C-section rates emphasizes the importance of prevention. However, there are no clear guidelines on intra-operative protocol to prevent postpartum niche formation. Besides surgical technique, the novel use of platelet-rich plasma (PRP) and mesenchymal stem cell (MSC) injections has demonstrated promising potential and may have applications in hysterotomy closures. The objective is to examine current research on optimal C-section procedures to prevent uterine niche formation and subsequent obstetric complications. A systematic review was conducted using PubMed and Google Scholar. Initial searches yielded 827 results. Inclusion criteria were human, animal, and in-vitro studies, peer-reviewed sources, and outcomes pertinent to the uterine niche. Exclusion criteria applied to articles with outcomes unrelated to myometrium and interventions outside of the intra-operative and immediate pre-/post-operative period. Based on the criteria, 41 articles were cited. Pathophysiology of uterine niche formation was associated with incisions through cervical tissue, adhesion formation, and poor approximation. Significant risk factors were low uterine incisions, advanced cervical dilatation, low station, non-closure of the peritoneum, and creation of a bladder flap. There was no consensus on uterine closure as it likely depends on surgical proficiency with the given technique, but a double-layered non-locking suture appears reliable to reduce niche severity. Recent trials indicate that intra-operative PRP/MSC injections may decrease niche incidence and severity, but more research is needed. If prevention or minimization of uterine niche is desired, the optimal C-section protocol should avoid low uterine incisions, choose uterine closure technique based on the surgeon's proficiency (double-layered non-locking is reliable), and close the peritoneum, and myometrial injection of PRP/MSC may be a useful adjunct intervention pending further clinical evidence.

Comparison of intra operative hemorrhage by blunt and sharp expansion of uterine incision at cesarean section

Objectives:

To compare the effect of blunt and sharp incision of uterus at cesarean section on intra-operative haemorrhage.

Methods:

This trial was conducted at the Department of Obstetrics and Gynaecology, Pakistan Ordinance Factory Hospital, Wah Cantt from 14^th January to 13^th July 2012. Total 80 women planned for lower segment cesarean section through Pfannensteil incision were randomized to either blunt uterine incision (Group-A, n=40) or sharp uterine incision (Group-B, n=40). The fall in Haemoglobin and HCT was compared in two groups and analyzed with help of SPSS version 10.

Results:

Both groups were similar in terms of demographic features like age, parity, gestational age and indication for cesarean section. The participants in Group-A reveled significantly less drop of mean Hb concentration as compared to Group-B (1.47±1.08 and 1.95±0.85 respectively, P value 0.031). Similarly, the fall in mean HCT was significantly less in Group-A in comparison to Group-B (3.21±1.3 and 4.21±2.17 respectively, P-value 0.015)

Conclusion:

Blunt expansion of uterine incision during caesarean section is associated with less fall in Haemoglobin and HCT as compared to sharp expansion.

Uterine exteriorization versus intraperitoneal repair: effect on intraoperative nausea and vomiting during repeat cesarean delivery - A randomized clinical trial

OBJECTIVE

The current study aims to compare the rate of intraoperative nausea and vomiting after repeat cesarean delivery (CD) under two different approaches: by intraperitoneal incision repair or by uterus exteriorization for incision reapair.

MATERIALS AND METHODS

We conducted a single-blinded randomized clinical trial (NCT03009994) at a tertiary University Hospital between the 1st of September 2016 and the 31st of December 2017. The study included pregnant women at term of gestation (>37 weeks) scheduled for repeat CD under spinal anesthesia. Women were assigned to either uterine exteriorization for incision repair (Group I) or intraperitoneal incision repair (Group II). The primary assessed was the rate of nausea and vomiting during CD.

RESULTS

The study included 1028 women in the final analysis. The rate of intraoperative nausea and vomiting was significantly lower in the intraperitoneal repair group compared to the exteriorization group (24% versus 38.7%, p= 0.001). Likewise, occurrence of uterine atony and the need for additional uterotonics were significantly lower in the intraperitoneal repair group (p= 0.001 and 0.02 respectively). Postoperatively, the rate of nausea and vomiting (12.6 % versus 21 %; P=0.001), and the time to the first recognized bowel movement (12.3 hours versus 14.1 hours; P=0.003) were significantly lower in the intraperitoneal repair group compared to the exteriorization group.

CONCLUSIONS

Intraperitoneal repair of the uterine incision during repeat CD is beneficial compared to exteriorization. Improvements in the rate of intra- and postoperative nausea, vomiting, uterine atony and time to the first recognized bowel movement were observed in patients operated with this technique.

Laparoscopic Management of Adhesions Developed after Peritoneal Nonclosure in Primary Cesarean Section Delivery

OBJECTIVE

The aim of the current study was to laparoscopically investigate the effects of peritoneal nonclosure on the sites, types, and degrees of adhesions developed after primary caesarean section (CS) in women complaining of secondary infertility after first CS delivery.

STUDY DESIGN

This was a cross-sectional study, where 250 women suffering from secondary infertility after their first CS had been recruited. They had been classified into group I (n = 89), where both the visceral and parietal peritoneum had been left opened; group II (n = 75), where only the parietal peritoneum had been closed; and group III (n = 86), where both peritoneal layers had been closed. Laparoscopy had been used to classify those adhesions according to the location, severity, and their adverse impact on the reproductive capacity.

RESULTS

Both adnexal and nonadnexal adhesions had been found significantly higher in group I, while adnexal types of adhesions were significantly higher after nonclosure of the visceral peritoneum in group II. Laparoscopic tubal surgery performed included tubo-ovariolysis, fimbrioplasty, and neosalpingostomy. Pregnancy rate was found correlating with the adnexal adhesion location and score.

CONCLUSION

Nonclosure of the peritoneum in CS is associated with more adhesion formation, which might adversely affect the future women reproduction.

Why do niches develop in Caesarean uterine scars? Hypotheses on the aetiology of niche development

Caesarean section (CS) results in the occurrence of the phenomenon 'niche'. A 'niche' describes the presence of a hypoechoic area within the myometrium of the lower uterine segment, reflecting a discontinuation of the myometrium at the site of a previous CS. Using gel or saline instillation sonohysterography, a niche is identified in the scar in more than half of the women who had had a CS, most with the uterus closed in one single layer, without closure of the peritoneum. An incompletely healed scar is a long-term complication of the CS and is associated with more gynaecological symptoms than is commonly acknowledged. Approximately 30% of women with a niche report spotting at 6-12 months after their CS. Other reported symptoms in women with a niche are dysmenorrhoea, chronic pelvic pain and dyspareunia. Given the association between a niche and gynaecological symptoms, obstetric complications and potentially with subfertility, it is important to elucidate the aetiology of niche development after CS in order to develop preventive strategies. Based on current published data and our observations during sonographic, hysteroscopic and laparoscopic evaluations of niches we postulate some hypotheses on niche development. Possible factors that could play a role in niche development include a very low incision through cervical tissue, inadequate suturing technique during closure of the uterine scar, surgical interventions that increase adhesion formation or patient-related factors that impair wound healing or increase inflammation or adhesion formation.

What are the best surgical techniques for caesarean sections? A contemporary review

The aim of this study was to evaluate the reported techniques used in caesarean sections in order to form a general perspective of the procedural options for this frequently performed operation. The PubMed database and Cochrane Reviews were searched separately with the key words 'caesarean', 'abdominal entry', 'abdominal incision', 'uterine repair', 'peritoneal repair', 'closure of abdominal incision', 'suture materials', 'extraction of the placenta' and 'review'. Reviews, meta-analyses and prospective randomised trials were included in this review. In conclusion, although caesarean delivery is a very common operation, standardised and globally accepted techniques for caesarean section have not been described. The best surgical techniques for this operation are still unknown. Although the long-term follow-up results from two large, prospective, randomised studies are pending, further research is needed to establish an evidence-based, standardised approach for caesarean sections.

Closure versus non-closure of the peritoneum at caesarean section: short- and long-term outcomes

BACKGROUND

Caesarean section is a very common surgical procedure worldwide. Suturing the peritoneal layers at caesarean section may or may not confer benefit, hence the need to evaluate whether this step should be omitted or routinely performed.

OBJECTIVES

The objective of this review was to assess the effects of non-closure as an alternative to closure of the peritoneum at caesarean section on intraoperative and immediate- and long-term postoperative outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 November 2013).

SELECTION CRITERIA

Randomised controlled trials comparing leaving the visceral or parietal peritoneum, or both, unsutured at caesarean section with a technique which involves suturing the peritoneum in women undergoing elective or emergency caesarean section.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked it for accuracy.

MAIN RESULTS

A total of 29 trials were included in this review and 21 trials (17,276 women) provided data that could be included in an analysis. The quality of the trials was variable. 1. Non-closure of visceral and parietal peritoneum versus closure of both parietal layersSixteen trials involving 15,480 women, were included and analysed, when both parietal peritoneum was left unclosed versus when both peritoneal surfaces were closed. Postoperative adhesion formation was assessed in only four trials with 282 women, and no difference was found between groups (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.76 to 1.29). There was significant reduction in the operative time (mean difference (MD) -5.81 minutes, 95% CI -7.68 to -3.93). The duration of hospital stay in a total of 13 trials involving 14,906 women, was also reduced (MD -0.26, 95% CI -0.47 to -0.05) days. In a trial involving 112 women, reduced chronic pelvic pain was found in the peritoneal non-closure group. 2. Non-closure of visceral peritoneum only versus closure of both peritoneal surfacesThree trials involving 889 women were analysed. There was an increase in adhesion formation (two trials involving 157 women, RR 2.49, 95% CI 1.49 to 4.16) which was limited to one trial with high risk of bias.There was reduction in operative time, postoperative days in hospital and wound infection. There was no significant reduction in postoperative pyrexia. 3. Non-closure of parietal peritoneum only versus closure of both peritoneal layersThe two identified trials involved 573 women. Neither study reported on postoperative adhesion formation. There was reduction in operative time and postoperative pain with no difference in the incidence of postoperative pyrexia, endometritis, postoperative duration of hospital stay and wound infection. In only one study, postoperative day one wound pain assessed by the numerical rating scale, (MD -1.60, 95% CI -1.97 to -1.23) and chronic abdominal pain d by the visual analogue score (MD -1.10, 95% CI -1.39 to -0.81) was reduced in the non-closure group. 4. Non-closure versus closure of visceral peritoneum when parietal peritoneum is closed.There was reduction in all the major urinary symptoms of frequency, urgency and stress incontinence when the visceral peritoneum is left unsutured.

AUTHORS' CONCLUSIONS

There was a reduction in operative time across all the subgroups. There was also a reduction in the period of hospitalisation post-caesarean section except in the subgroup where parietal peritoneum only was not sutured where there was no difference in the period of hospitalisation. The evidence on adhesion formation was limited and inconsistent. There is currently insufficient evidence of benefit to justify the additional time and use of suture material necessary for peritoneal closure. More robust evidence on long-term pain, adhesion formation and infertility is needed.

Surgical techniques for uterine incision and uterine closure at the time of caesarean section

BACKGROUND

Caesarean section is a common operation. Techniques vary depending on both the clinical situation and the preferences of the operator.

OBJECTIVES

To compare the effects of 1) different types of uterine incision, 2) methods of performing the uterine incision, 3) suture materials and technique of uterine closure (including single versus double layer closure of the uterine incision) on maternal health, infant health, and healthcare resource use.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 September 2013) and reference lists of all identified papers.

SELECTION CRITERIA

All published, unpublished, and ongoing randomised controlled trials comparing various types and closure of uterine incision during caesarean section.

DATA COLLECTION AND ANALYSIS

Two review authors evaluated trials for inclusion and methodological quality without consideration of their results according to the stated eligibility criteria and extracted data independently.

MAIN RESULTS

Our search strategy identified 60 studies for consideration, of which 27 randomised trials involving 17,808 women undergoing caesarean section were included in the review. Overall, the methodological quality of the trials was variable, with 12 of the 27 included trials adequately describing the randomisation sequence, with less than half describing adequately methods of allocation concealment, and only six trials indicating blinding of outcome assessors.Two trials compared auto-suture devices with traditional hysterotomy involving 300 women. No statistically significant difference in febrile morbidity between the stapler and conventional incision groups was apparent (risk ratio (RR) 0.92; 95% confidence interval (CI) 0.38 to 2.20).Five studies were included in the review that compared blunt versus sharp dissection when performing the uterine incision involving 2141 women. There were no statistically significant differences identified for the primary outcome febrile morbidity following blunt or sharp extension of the uterine incision (four studies; 1941 women; RR 0.86; 95% CI 0.70 to 1.05). Mean blood loss (two studies; 1145 women; average mean difference (MD) -55.00 mL; 95% CI -79.48 to -30.52), and the need for blood transfusion (two studies; 1345 women; RR 0.24; 95% CI 0.09 to 0.62) were significantly lower following blunt extension.A single trial compared transverse with cephalad-caudad blunt extension of the uterine incision, involving 811 women, and while mean blood loss was reported to be lower following transverse extension (one study; 811 women; MD 42.00 mL; 95% CI 1.31 to 82.69), the clinical significance of such a small volume difference is of uncertain clinical relevance. There were no other statistically significant differences identified for the limited outcomes reported.A single trial comparing chromic catgut with polygactin-910, involving 9544 women reported that catgut closure versus closure with polygactin was associated with a significant reduction in the need for blood transfusion (one study, 9544 women, RR 0.49, 95% CI 0.32 to 0.76) and a significant reduction in complications requiring re-laparotomy (one study, 9544 women, RR 0.58, 95% CI 0.37 to 0.89).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 (nine studies; 13,890 women; RR 0.98; 95% CI 0.85 to 1.12). 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 risk of blood transfusion (four studies; 13,571 women; average RR 0.86; 95% CI 0.63 to 1.17; Heterogeneity: Tau² = 0.15; I² = 49%), or other reported clinical outcomes.

AUTHORS' CONCLUSIONS

Caesarean 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.

Closure of the uterine incision with one or two layers after caesarean section: a randomized controlled study in sheep

OBJECTIVE

To compare the quality of the uterine scar with one or two layer closure after caesarean section by studying biomechanical and pathological properties of the scar.

METHODS

A randomized controlled trial performed on eight term pregnant ewes assigned into two groups during caesarean according to type of uterine closure: single-layer or double-layer. Hysterectomy was performed 8 months after caesarean delivery. Tensile strength of all scars and of unscarred myometrium was measured. Pathological properties of the scars were analyzed histologically.

RESULTS

The force required to reach the yield point was similar between scarred and unscarred myometrium (p=0.96), and between the scars in single-layer and double-layer closure groups (p=0.65). There was a significant increase in fibrosis width on the superficial part of the uterus in the double-layer closure group compared to the single-layer group (p=0.02).

CONCLUSIONS

Double-layer uterine closure modified wound healing without significant change in biomechanical properties.

Caesarean section surgical techniques (CORONIS): a fractional, factorial, unmasked, randomised controlled trial

BACKGROUND

Variations exist in the surgical techniques used for caesarean section and many have not been rigorously assessed in randomised controlled trials. We aimed to assess whether any surgical techniques were associated with improved outcomes for women and babies.

METHODS

CORONIS was a pragmatic international 2×2×2×2×2 non-regular fractional, factorial, unmasked, randomised controlled trial that examined five elements of the caesarean section technique in intervention pairs. CORONIS was undertaken at 19 sites in Argentina, Chile, Ghana, India, Kenya, Pakistan, and Sudan. Each site was assigned to three of the five intervention pairs: blunt versus sharp abdominal entry; exteriorisation of the uterus for repair versus intra-abdominal repair; single-layer versus double-layer closure of the uterus; closure versus non-closure of the peritoneum (pelvic and parietal); and chromic catgut versus polyglactin-910 for uterine repair. Pregnant women were eligible if they were to undergo their first or second caesarean section through a planned transverse abdominal incision. Women were randomly assigned by a secure web-based number allocation system to one intervention from each of the three assigned pairs. All investigators, surgeons, and participants were unmasked to treatment allocation. The primary outcome was the composite of death, maternal infectious morbidity, further operative procedures, or blood transfusion (>1 unit) up to the 6-week follow-up visit. Women were analysed in the groups into which they were allocated. The CORONIS Trial is registered with Current Controlled Trials: ISRCTN31089967.

FINDINGS

Between May 20, 2007, and Dec 31, 2010, 15 935 women were recruited. There were no statistically significant differences within any of the intervention pairs for the primary outcome: blunt versus sharp entry risk ratio 1·03 (95% CI 0·91-1·17), exterior versus intra-abdominal repair 0·96 (0·84-1·08), single-layer versus double-layer closure 0·96 (0·85-1·08), closure versus non-closure 1·06 (0·94-1·20), and chromic catgut versus polyglactin-910 0·90 (0·78-1·04). 144 serious adverse events were reported, of which 26 were possibly related to the intervention. Most of the reported serious adverse events were known complications of surgery or complications of the reasons for the caesarean section.

INTERPRETATION

These findings suggest that any of these surgical techniques is acceptable. However, longer-term follow-up is needed to assess whether the absence of evidence of short-term effects will translate into an absence of long-term effects.

FUNDING

UK Medical Research Council and WHO.

Abdominal surgical incisions for caesarean section

BACKGROUND

Caesarean section is the commonest major operation performed on women worldwide. Operative techniques, including abdominal incisions, vary. Some of these techniques have been evaluated through randomised trials.

OBJECTIVES

To determine the benefits and risks of alternative methods of abdominal surgical incisions for caesarean section.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 February 2013).

SELECTION CRITERIA

Randomised controlled trials of intention to perform caesarean section using different abdominal incisions.

DATA COLLECTION AND ANALYSIS

We extracted data from the sources, checked them for accuracy and analysed the data.

MAIN RESULTS

Four studies (666 women) were included in this review.Two studies (411 women) compared the Joel-Cohen incision with the Pfannenstiel incision. Overall, there was a 65% reduction in reported postoperative febrile morbidity (risk ratio (RR) 0.35, 95% confidence interval (CI) 0.14 to 0.87) with the Joel-Cohen incision. One of the trials reported reduced postoperative analgesic requirements (RR 0.55, 95% CI 0.40 to 0.76); operating time (mean difference (MD) -11.40, 95% CI -16.55 to -6.25 minutes); delivery time (MD -1.90, 95% CI -2.53 to -1.27 minutes); total dose of analgesia in the first 24 hours (MD -0.89, 95% CI -1.19 to -0.59); estimated blood loss (MD -58.00, 95% CI -108.51 to -7.49 mL); postoperative hospital stay for the mother (MD -1.50, 95% CI -2.16 to -0.84 days); and increased time to the first dose of analgesia (MD 0.80, 95% CI 0.12 to 1.48 hours) compared with the Pfannenstiel group. No other significant differences were found in either trial.Two studies compared muscle cutting incisions with Pfannenstiel incision. One study (68 women) comparing Mouchel incision with Pfannenstiel incision did not contribute data to this review. The other study (97 women) comparing the Maylard muscle-cutting incision with the Pfannenstiel incision, reported no difference in febrile morbidity (RR 1.26, 95% CI 0.08 to 19.50); need for blood transfusion (RR 0.42, 95% CI 0.02 to 9.98); wound infection (RR 1.26, 95% CI 0.27 to 5.91); physical tests on muscle strength at three months postoperative and postoperative hospital stay (MD 0.40 days, 95% CI -0.34 to 1.14).

AUTHORS' CONCLUSIONS

The Joel-Cohen incision has advantages compared with the Pfannenstiel incision. These are: less fever, pain and analgesic requirements; less blood loss; shorter duration of surgery and hospital stay. These advantages for the mother could be extrapolated to savings for the health system. However, these trials do not provide information on severe or long-term morbidity and mortality.

Infectious morbidity after cesarean delivery: 10 strategies to reduce risk

Puerperal infection remains a major cause of maternal morbidity and mortality. The primary risk factor is cesarean delivery, which increases the risk 5- to 20-fold. This article reviews in detail the risk of puerperal infection following cesarean delivery, both endometritis and surgical site infection, in both high- and low-risk populations. Strategies to prevent such infections are also discussed using a systematic evidence-based approach.

Evidence-based cesarean technique

PURPOSE OF REVIEW

Cesarean section is the most common surgical procedure performed on US women, and rates of cesarean delivery continue to increase.

RECENT FINDINGS

Recent studies on operative technique in cesarean section have contributed significantly to our knowledge of antibiotic prophylaxis, bladder flap formation, management of the uterine repair and closure of the peritoneum and skin. There is compelling evidence that antibiotics should be given prior to skin incision rather than the traditional administration after cord clamping. Additionally, evidence suggesting benefit to multiagent, extended-coverage regimens is mounting. Recent studies challenge the accepted practice of creating a bladder flap in cesarean section. Uterine repair can be safely accomplished either intra or extraabdominally but the debate over single versus double-layer closure continues. Nonclosure of the visceral peritoneum confers significant benefit, but recent evidence suggests that closure of the parietal layer may be advantageous with respect to future adhesions.

SUMMARY

It is imperative that all technical aspects in cesarean section continue to be challenged. Widely accepted aspects, including antibiotics administration at cord clamping and creation of a bladder flap, may not be best practice.

Short-term effects of closure versus non-closure of the visceral and parietal peritoneum at cesarean section: a prospective randomized study

AIM

To determine the effect of non-closure of the visceral and parietal peritoneum during cesarean section on short-term postoperative morbidity.

METHODS

A prospective randomized trial was conducted of 533 women undergoing primary cesarean section; 277 were randomized to closure and 256 to non-closure of the peritoneum. Perioperative outcome measures, such as analgesia dosage and morbidly measures were compared.

RESULTS

There was no significant difference between the non-closure and closure groups in the mean number of narcotic analgesia doses (1.09 +/- 1.2 vs 1.05 +/- 1.0, P = 0.63; respectively), mean number of non-narcotic analgesia doses (4.69 +/- 2.7 vs 4.65 +/- 2.8, P = 0.89; respectively), number of women with postoperative fever >38 degrees C (18 vs 14, P = 0.37; respectively), number of women with wound infection (29 vs 35, P = 0.54; respectively) and mean number of hospitalization days (4.16 +/- 0.91 vs 4.14 +/- 0.71, P = 0.78; respectively).

CONCLUSION

Closure or non-closure of the peritoneum at cesarean sections has no significant impact on postoperative analgesic usage and short-term morbidity.

Extraabdominal vs intraabdominal uterine repair at cesarean delivery: a metaanalysis

OBJECTIVE

Cesarean section delivery is a commonly performed surgical procedure, and rates of cesarean delivery are increasing. Previous randomized trials that compared extraabdominal and intraabdominal uterine repair at cesarean section delivery have yielded conflicting results.

STUDY DESIGN

We conducted a metaanalysis of published randomized controlled trials that addressed the method of uterine repair at cesarean delivery. The primary outcome was incidence of perioperative complications. The secondary outcomes were operative time, estimated blood loss, and hospital stay. Pooled odds ratios were calculated for categoric variables with random effects models. Continuous variables were compared by means of weighted mean differences.

RESULTS

No significant differences in either postoperative or intraoperative complications were demonstrated between the extraabdominal (n = 1605) and intraabdominal repair (n = 1578) groups. Operative time, estimated blood loss, and hospital stay were all unaffected by repair technique. This study cannot exclude differences in rare complications, such as serious venous air embolism or maternal death.

CONCLUSION

No differences in complication rates were found between extraabdominal and intraabdominal repair at cesarean section delivery; both techniques are valid surgical options.

Neonatal mortality, risk factors and causes: a prospective population-based cohort study in urban Pakistan

OBJECTIVE

To evaluate the prevalence, sex distribution and causes of neonatal mortality, as well as its risk factors, in an urban Pakistani population with access to obstetric and neonatal care.

METHODS

Study area women were enrolled at 20-26 weeks' gestation in a prospective population-based cohort study that was conducted from 2003 to 2005. Physical examinations, antenatal laboratory tests and anthropometric measures were performed, and gestational age was determined by ultrasound to confirm eligibility. Demographic and health data were also collected on pretested study forms by trained female research staff. The women and neonates were seen again within 48 hours postpartum and at day 28 after the birth. All neonatal deaths were reviewed using the Pattinson et al. system to assign obstetric and final causes of death; the circumstances of the death were determined by asking the mother or family and by reviewing hospital records. Frequencies and rates were calculated, and 95% confidence intervals were determined for mortality rates. Relative risks were calculated to evaluate the associations between potential risk factors and neonatal death. Logistic regression models were used to compute adjusted odds ratios.

FINDINGS

Birth outcomes were ascertained for 1280 (94%) of the 1369 women enrolled. The 28-day neonatal mortality rate was 47.3 per 1000 live births. Preterm birth, Caesarean section and intrapartum complications were associated with neonatal death. Some 45% of the deaths occurred within 48 hours and 73% within the first week. The primary obstetric causes of death were preterm labour (34%) and intrapartum asphyxia (21%). Final causes were classified as immaturity-related (26%), birth asphyxia or hypoxia (26%) and infection (23%). Neither delivery in a health facility nor by health professionals was associated with fewer neonatal deaths. The Caesarean section rate was 19%. Almost all (88%) neonates who died received treatment and 75% died in the hospital.

CONCLUSION

In an urban population with good access to professional care, we found a high neonatal mortality rate, often due to preventable conditions. These results suggest that, to decrease neonatal mortality, improved health service quality is crucial.

Conception, complicated pregnancy, and labour of gods and heroes in Greek mythology

Pregnancy and labour are holy moments in a woman's life. Even in Greek mythology we can find descriptions of them. We searched in the Greek myths to find descriptions of labours of ancient heroes and gods. We identified descriptions of extracorporeal fertilization, superfecundation, ectopic pregnancy, preterm labour, prolonged pregnancy and Caesarean section. The use of imagination could help the reader to find similarities in present or future developments in the field of obstetrics. It could be concluded that various aspects of modern obstetrical practice are described in Greek mythology.

Surgical techniques for uterine incision and uterine closure at the time of caesarean section

BACKGROUND

Caesarean section is a common operation. Techniques vary depending on both the clinical situation and the preferences of the operator.

OBJECTIVES

To compare the effects of 1) different types of uterine incision, 2) methods of performing the uterine incision, 3) suture materials and technique of uterine closure (including single versus double layer closure of the uterine incision) on maternal health, infant health, and health care resource use.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (November 2007).

SELECTION CRITERIA

All published, unpublished, and ongoing randomised controlled trials comparing various types and closure of uterine incision during caesarean section.

DATA COLLECTION AND ANALYSIS

Two authors evaluated trials for inclusion and methodological quality without consideration of their results according to the stated eligibility criteria and extracted data independently.

MAIN RESULTS

We identified 30 studies, of which 15 (3972 women) were included. Ten trials compared single layer uterine closure with double layer uterine closure (2531 women), two trials compared blunt with sharp dissection at the time of the uterine incision (1241 women), and two trials compared auto-suture devices with traditional hysterotomy (300 women). Blunt dissection was associated with a reduction in mean blood loss at the time of the procedure when compared with sharp dissection of the uterine incision (one study, 945 women, mean difference (MD) -43.00, 95% confidence interval (CI) -66.12 to -19.88). There was no statistically significant difference related to need for blood transfusion (one study, 945 women, risk ratio (RR) 0.22, 95% CI 0.05 to 1.01). The use of an auto-suture instrument when compared with traditional methods of hysterotomy was associated with no difference in the amount of blood loss during the procedure (one study, 200 women, MD -87.00, 95% CI -175.09 to 1.09), but a statistically significant increase in the duration of the procedure (one study, 197 women, MD 3.30, 95% CI 0.02 to 6.62). Single layer closure compared with double layer closure was associated with a statistically significant reduction in mean blood loss (three studies, 527 women, MD -70.11, 95% CI -101.61 to -38.60); duration of the operative procedure (four studies, 645 women, MD -7.43, 95% CI -8.41 to -6.46); and presence of postoperative pain (one study, 158 women, RR 0.69, 95% CI 0.52 to 0.91).

AUTHORS' CONCLUSIONS

While caesarean section is a common procedure performed on women worldwide, there is little information available to inform the most appropriate surgical technique to adopt.

Techniques for caesarean section

BACKGROUND

Rates of caesarean section (CS) have been rising globally. It is important to use the most effective and safe technique.

OBJECTIVES

To compare the effects of complete methods of caesarean section; and to summarise the findings of reviews of individual aspects of caesarean section technique.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (August 2007), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2007, Issue 3) and reference lists of identified papers.

SELECTION CRITERIA

Randomised controlled trials of intention to perform caesarean section using different techniques.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies and extracted data.

MAIN RESULTS

'Joel-Cohen based' compared with Pfannenstiel CS was associated with: less blood loss, (five trials, 481 women; weighted mean difference (WMD) -64.45 ml; 95% confidence interval (CI) -91.34 to -37.56 ml); shorter operating time (five trials, 581 women; WMD -18.65; 95% CI -24.84 to -12.45 minutes); postoperatively, reduced time to oral intake (five trials, 481 women; WMD -3.92; 95% CI -7.13 to -0.71 hours); less fever (eight trials, 1412 women; relative risk (RR) 0.47; 95% CI 0.28 to 0.81); shorter duration of postoperative pain (two comparisons from one trial, 172 women; WMD -14.18 hours; 95% CI -18.31 to -10.04 hours); fewer analgesic injections (two trials, 151 women; WMD -0.92; 95% CI -1.20 to -0.63); and shorter time from skin incision to birth of the baby (five trials, 575 women; WMD -3.84 minutes; 95% CI -5.41 to -2.27 minutes). Serious complications and blood transfusions were too few for analysis.Misgav-Ladach compared with the traditional method (lower midline abdominal incision) was associated with reduced: blood loss (339 women; WMD -93.00; 95% CI -132.72 to -53.28 ml); operating time (339 women; WMD-7.30; 95% CI -8.32 to -6.28 minutes); time to mobilisation (339 women; WMD -16.06; 95% CI -18.22 to -13.90 hours); and length of postoperative stay for the mother (339 women; WMD -0.82; 95% CI -1.08 to -0.56 days). Misgav-Ladach compared with modified Misgav-Ladach methods was associated with a longer time from skin incision to birth of the baby (116 women; WMD 2.10; 95% CI 1.10 to 3.10 minutes).

AUTHORS' CONCLUSIONS

'Joel-Cohen based' methods have advantages compared to Pfannenstiel and to traditional (lower midline) CS techniques, which could translate to savings for the health system. However, these trials do not provide information on mortality and serious or long-term morbidity such as morbidly adherent placenta and scar rupture.

Extra-abdominal versus intra-abdominal repair of the uterine incision at caesarean section

BACKGROUND

Different techniques have been described to reduce morbidity during caesarean section. After the baby has been born by caesarean section and the placenta has been extracted, temporary removal of the uterus from the abdominal cavity (exteriorisation of the uterus) to facilitate repair of the uterine incision has been postulated as a valuable technique. This is particularly so when exposure of the incision is difficult and when there are problems with haemostasis. Several clinical trials have been done, with varying results, including substantial reduction in the rate of postoperative infection and morbidity with extra-abdominal closure of the uterine incision, and less associated peri-operative haemorrhage. Subsequent studies suggest that the method of placental removal rather than method of closure of the uterine incision influences peri-operative morbidity.

OBJECTIVES

To evaluate the effects of extra-abdominal repair of the uterine incision compared to intra-abdominal repair.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (September 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2003), MEDLINE (1966 to July 2003) and PubMed (1966 to 2003).

SELECTION CRITERIA

Randomised controlled trials involving a comparison of uterine exteriorisation with intra-abdominal repair of the uterine incision in women undergoing caesarean section.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed the trials identified for inclusion. We compared categorical data using relative risks and 95% confidence intervals and continuous data using the weighted mean difference with 95% confidence intervals. We tested for statistical heterogeneity between trials using the I squared test. Where no significant heterogeneity (greater than 50%) existed, we pooled data using a fixed effect model. If significant heterogeneity existed, a random effects model was used.

MAIN RESULTS

Six studies were included, with 1294 women randomised overall, and 1221 women included in the analysis. There were no statistically significant differences between the groups in most of the outcomes identified, except for febrile morbidity and length of hospital stay. With extra-abdominal closure of the uterine incision, febrile morbidity was lower (relative risk 0.41, 95% confidence interval (CI) 0.17 to 0.97), and the hospital stay was longer (weighted mean difference 0.24 days, 95% CI 0.08 to 0.39).

REVIEWERS' CONCLUSIONS

There is no evidence from this review to make definitive conclusions about which method of uterine closure offers greater advantages, if any. However, these results are based on too few and too small studies to detect differences in rare, but severe, complications.

Closure versus non-closure of the peritoneum at caesarean section

BACKGROUND

Caesarean section is a very common surgical procedure world wide. Suturing the peritoneal layers at caesarean section may or may not confer benefit, hence the need to evaluate whether this step should be omitted or not.

OBJECTIVES

The objective of this review was to assess the effects of non-closure as an alternative to closure of the peritoneum at caesarean section on intra-operative, immediate and long-term postoperative and long-term outcomes.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (November 2002).

SELECTION CRITERIA

Controlled trials comparing leaving the visceral and/or parietal peritoneum unsutured at caesarean section with a technique which involves suturing the peritoneum in women undergoing elective or emergency caesarean section.

DATA COLLECTION AND ANALYSIS

Trial quality was assessed and data were extracted by two reviewers.

MAIN RESULTS

Nine trials involving 1811 women were included and analysed. The methodological quality of the trials was variable. Non-closure of the peritoneum reduced operating time whether both or either layer was not sutured. For both layers, the operating time was reduced by 7.33 minutes, 95% confidence interval (CI) -8.43 to -6.24. There was significantly less postoperative fever and reduced postoperative stay in hospital for visceral peritoneum and for both layer non-closure. There were no other statistically significant differences. The trend for analgesia requirement and wound infection tended to favour non-closure, while endometritis results were variable. Long-term follow up in one trial showed no significant differences. The power of the study to show differences was low.

REVIEWER'S CONCLUSIONS

There was improved short-term postoperative outcome if the peritoneum was not closed. Long-term studies following caesarean section are limited, but data from other surgical procedures are reassuring. There is at present no evidence to justify the time taken and cost of peritoneal closure.