Introduction

The rates of lower-segment cesarean sections (LSCS) have been increasing in the last decades aiming to improve maternal and fetal outcomes.1 According to the World Health Organization (WHO), LSCS constitutes as high as 15% of all deliveries worldwide.² This rise in LSCS rates comes with risks including postpartum bleeding, anesthesia-related complications, and infections.

Literature has shown that LSCS increases the risk of maternal infections by five to twenty times when compared to vaginal delivery. Surgical site infections (SSI) and urinary tract infections (UTI) are the main healthcare-associated infections.1 An SSI is an infection involving the abdominal incision or deep tissue within 30 days after surgery.³ Every year, SSIs endanger millions of patients' lives and contribute to the development of antibiotic resistance. More than 10% of patients undergoing lower segment cesarean section (LSCS) in low- and middle-income countries develop SSI.⁴ Globally, the estimated rate of LSCS-related SSI is around 6%.⁵

Post-LSCS SSI can lead to a considerable negative impact on maternal and neonatal outcomes leading to delayed recovery, increased length of hospital stays, and higher morbidity and mortality.⁶ Even with the availability of antibiotics, managing SSI remains challenging in some cases.⁷ Therefore, many guidelines recommend a comprehensive evaluation of patients undergoing LSCS is essential to mitigate SSI risks. This evaluation should aim to identify areas that can be amended before, during, and after LSCS to lower the risk of occurrence of SSI.^8-9 Coordinated efforts aimed at reducing the risks of SSIs were shown to be effective.⁹

One step to avoid SSI among patients undergoing LSCS is to identify patients at higher risk of LSCS. Many studies were conducted to identify the risk factors of SSI. According to the literature, several risk factors have been associated with post-LSCS SSI. These include obesity, diabetes mellitus, prolonged labor, prolonged rupture of membranes, multiple vaginal examinations, emergency cesarean section, excessive blood loss, and prolonged operative time.^12-15 A systematic review also identified factors such as chorioamnionitis, previous cesarean delivery, lack of antibiotic prophylaxis, and lower socioeconomic status as significant risk factors.¹⁶ Additionally, tobacco use, hypertension, and corticosteroid use were found to be associated with increased SSI risk following cesarean delivery.¹⁷

Although many studies were done to identify the risk factors of post-LSCS infection, no previous studies were conducted to assess this topic in Bahrain. To close this gap, this study aimed to identify the risk factors associated with the occurrence of SSI among females who underwent an LSCS at Salmaniya Medical Complex (SMC), Bahrain.

Method

Design and setting

A retrospective analytical study was conducted at the Obstetrics and Gynecology Department at Salmaniya Medical Complex (SMC). SMC is a tertiary center that provides medical services to citizens and residents in Bahrain.

Selection criteria

Patients who underwent either emergency or elective LSCS in the period between 2022-2023 were eligible for inclusion.

Sample size

Based on a total number of LSCS of 8011, assumed 10.3% of cases were diagnosed with post-LSCS wound infections, an acceptable estimate of 5%, a design effect of 1 and a confidence interval (CI) of 95%, the total sample size that was considered in this study was 343 pateints.

Sampling process

In the period between 2020-2023, a total of 8011 females underwent LSCS at SMC. All females who got SSI were recruited in the study, while a comparable sample was taken from those who did not have SSI post-LSCS. The data was collected during the period between March and April of 2024.

Diagnosis of cellulitis and bloody discharges, stitch abscess alone (minimal inflammation and discharge confined to the points of suture penetration), patients presented after 30 days of surgery were not included in the cases group. Patients were considered as SSI based on criteria set by the CDC.11 The patient presentation must be within 30 days of surgery AND have at least one of the following:

  a. purulent drainage from the superficial incision.

  b. organism(s) identified from an aseptically obtained specimen from tissue by a culture or        nonculture-based microbiologic testing method which is performed for purposes of                clinical diagnosis or treatment.

  c. a superficial incision that is deliberately opened by a surgeon, physician, or physician             designee and patient must have at least one of the following signs or symptoms:                   localized pain or tenderness; localized swelling; erythema; or heat.

Another 172 females who did not develop SSI were selected to serve as controls. Females that were proven to be free from SSI and were operated on during the selected period and had complete medical records were considered controls, however only 172 consecutive females were chosen until attaining the required sample (Figure 1).

Data collection process

Patients’ names who underwent LSCS were collected from the registry logbook of the hospital in all the surgical wards, and then the electronic medical records (iSeha) were used to collect the relevant data. The data was coded and anonymized.

Ethical consideration

The protocol of the present research was approved by the Research and Research Ethics Committee at SMC number 80090723. Since there was no direct contact with cases, no informed consent was considered for the study.

Data management

Numerical data were presented as median and Interquartile range (IQR), while categorical data were described using frequencies and percentages. As appropriate, the chi-square test, fisher exact test, and Mann-Whitney test were performed. All statistical calculations were done using SPSS (Statistical Package for the Social Science; SPSS Inc., Chicago, IL, USA) version 27 and Prism Graph Pad. For all analyses, a P value of less than 0.05 was considered statistically significant.

Results

Out of a total of 8301 LSCS surgeries, 171 cases had SSI constituting an incidence of 2.1% (Figure 2)

Table 1 presents the association between patient characteristics and risk of SSI. A significant association was found between diabetes mellitus and post-LSCS SSI (p<0.001). Patients who underwent emergency LSCS had a higher rate of post-LSCS SSI compared to their counterparts (p<0.001). In addition, a significant association was found between hospital stay length and SSI postLSCS (p=0.005). Pre and post-operative blood pressure was also significantly different between both groups (p<0.05).

Table 2 shows the logistic regression analysis of risk factors of SSI among women who underwent LSCS. The presence of diabetes mellitus was significantly protective against the occurrence of SSI (OR=0.29, 95% CI=0.15-0.58; P<0.001). Also, emergency LSCS was associated with a 4.82 times higher risk of occurrence of SSI compared to the elective LSCS (OR=414, 95% CI=2.17-7.9; P<0.001). A one-day increase in hospital stay was associated with a 37% increase in the likelihood of SSI (OR=1.37, 95% CI=1.11-1.7; P=0.003). In addition to that, having stage 1 pre-operative sitting blood pressure was associated with increased risk for SSI (OR=2.66, 95% CI=1.16-6.12; P=0.021), while having post-operative elevated laying blood pressure was associated with decreased risk for SSI (OR=0.42, 95% CI=0.22-0.8; P=0.009).

Discussion

This study aimed to determine the prevalence and risk factors of post-LSCS SSI among patients in SMC. The study revealed an SSI rate of 2.13% with a higher risk among patients who had longer hospital stays and had emergency LSCS. This rate of SSI post-LSCS is consistent with global findings that report SSI rates post-cesarean delivery ranging from 5% to 20%.¹⁸ The reported rate of SSI in this study is lower than that reported by Gupta et al. (10.3%) but comparable to the rate reported by Ketcheson et al (2.7%).^1,6 The variation in the rates of SSI in the post-LSCS period can be attributed to different preventive measures, patients’ characteristics, and research methods.

The data of this study revealed that emergency LSCS was significantly associated with a 4.14- fold increase in the risk of SSI compared to elective procedures. This aligns with the existing literature that consistently shows higher rates of SSI in emergency surgeries. Possible reasons for this finding include higher contamination risk, suboptimal patient preparation, and often poorer patient health status at the time of surgery.⁷ Contrary to our study, Gupta et al. found no association between the type of LSCS and the risk of SSI.¹ The high proportion of emergency surgeries (84.2% in SSI cases) underscores the need for enhanced preoperative optimization and risk stratification protocols for patients undergoing emergency cesarean sections.

Our findings indicated that each additional day of hospital stay was associated with a 37% increase in the likelihood of developing SSI. This correlation suggests that prolonged hospitalization may expose patients to additional risks of nosocomial infections. This observation resonates with the work of Zimlichman et al. who highlighted that longer hospital stays increase exposure to pathogens and complicate recovery.²¹ Interestingly, our study identified that elevated pre-operative sitting blood pressure was associated with increased SSI risk (OR=2.66, 95% CI=1.16-6.12; P=0.021), whereas elevated post-operative laying blood pressure was linked to a decreased risk of SSI (OR=0.42, 95% CI=0.22-0.8; P=0.009). These findings suggest a complex relationship between hemodynamic status and infection risk, indicating that hypertension may compromise immune response or contribute to vascular complications that predispose patients to infection.²² Further research is warranted to elucidate these relationships.

One of the most surprising findings of our study was the significant association between diabetes mellitus and the incidence of SSI. Contrary to expectations that diabetes would heighten the risk of infection, our results indicated that the presence of DM was significantly protective against SSI. This finding is paradoxical and may warrant further investigation into the role of preoperative blood glucose management and perioperative care in diabetic patients. Previous studies have shown that diabetes has increased the risk of SSI.19 Also, a systematic review that recruited eight studies to investigate the relationship between glycemic control strategies performed and the occurrence of surgical site infection in adult patients undergoing surgery, concluded that proper glycemic control gave satisfactory results in preventing the occurrence of SSI.20 This finding suggests that careful metabolic control preoperatively could be a critical factor in reducing SSI rates.

This study recommends adopting strategies to minimize hospital stays, improve the care of patients undergoing emergency LSCS, and apply strict preventive measures in these patients.

This study carries inherent limitations, including its retrospective design, which may introduce selection bias. Furthermore, the single-center nature of the study limits the generalizability of findings to broader populations. Further prospective studies to determine the influence of diabetes on SSI among women who underwent LSCS are needed.

Conclusion

In summary, this study revealed a low rate of SSI among women who underwent LSCS in SMC in Bahrain. Patients who had emergency surgery and who were admitted for longer duration were at a higher risk of SSI compared to their counterparts. Surprisingly, patients with diabetes were found to have lower risks of SSI post-LSCS. Further studies to determine the effective measures to mitigate the risks of SSI among patients undergoing LSCS are needed.

Source of funding

This study did not receive any source of funding.

Conflict of interest

The authors declared no conflict of interest.

Acknowledgment

The authors would like to thank the administrators at SMC who gave valuable help and support to conduct this study.