Abstract
Objective:
To compare perioperative outcomes of emergency gynecologic surgeries performed during working hours and off-hours, and to evaluate temporal trends in surgical approach, particularly laparoscopy.
Methods:
This retrospective cohort study included patients who underwent emergency surgery for ovarian torsion, ovarian cyst rupture, or ruptured tubal ectopic pregnancy between January 1, 2020 and October 1, 2025 at a tertiary referral center. Patients were grouped according to surgical timing as working hours or off-hours. Demographic characteristics, surgical approach, operative time, hemoglobin decrease, transfusion requirement, hospital stay, intraoperative and postoperative complications, and reoperation were compared within each diagnostic group. Annual trends in surgical approach were also analyzed, and multivariable linear regression assessed the association of off-hours surgery with operative time and length of hospital stay.
Results:
A total of 386 patients were included: 69 with ovarian torsion, 77 with ovarian cyst rupture, and 240 with ruptured tubal ectopic pregnancy. Most procedures were performed during off-hours. In ovarian torsion and ovarian cyst rupture, perioperative outcomes were comparable between groups. In ruptured tubal ectopic pregnancy, operative time was longer during off-hours than during working hours and remained independently associated with off-hours surgery after adjustment, while hemoglobin decrease, transfusion requirement, hospital stay, complications, and reoperation rates were similar. The proportion of laparoscopic procedures increased from 17.9% in 2020 to 90.0% in the first 9 months of 2025.
Conclusion:
Off-hours emergency gynecologic surgery showed largely comparable outcomes to working-hours surgery. The marked shift toward laparoscopy suggests increasing integration of minimally invasive surgery into emergency gynecologic practice.
Keywords: Gynecologic emergencies, Laparoscopy, Off-hours surgery, Ovarian cyst rupture, Ovarian torsion
INTRODUCTION
Emergency gynecologic surgery is performed for acute conditions such as ruptured ectopic pregnancy, ovarian torsion, and ovarian cyst rupture. These patients often present with severe pelvic pain, hemoperitoneum, or hemodynamic instability, requiring urgent surgical intervention. Because these cases occur unpredictably, surgery is frequently performed outside routine working hours.1
Several studies in general surgery have suggested that operations performed during off-hours may be associated with worse outcomes because of factors such as clinician fatigue, reduced staffing, and limited resource availability.2 However, findings have been inconsistent, and outcomes appear to depend on surgical urgency, institutional resources, and patient complexity.3–11 Evidence specific to gynecologic surgery remains limited, with conflicting reports regarding the impact of operative timing on perioperative outcomes.12,13
Emergency gynecologic care presents unique challenges because delays in treatment may adversely affect outcomes in conditions such as ovarian torsion and ruptured ectopic pregnancy.14–16 At the same time, minimally invasive surgery has become increasingly used in emergency gynecology, offering potential benefits including reduced morbidity and shorter hospital stay.14,15,17
Despite growing interest in the effect of operative timing, few studies have specifically evaluated common emergency gynecologic pathologies. Therefore, the aim of this study was to compare perioperative outcomes of emergency surgery for ovarian torsion, ovarian cyst rupture, and ruptured tubal ectopic pregnancy performed during working hours versus off-hours. A secondary objective was to assess temporal trends in surgical approach, particularly the adoption of laparoscopy in emergency gynecologic surgery.
METHODOLOGY
This retrospective cohort study included patients who underwent emergency gynecologic surgery between January 1, 2020 and October 1, 2025 at a tertiary referral center. The study was designed to compare perioperative outcomes of emergency gynecologic operations performed during working hours and off-hours, and to evaluate annual changes in surgical approach over the study period. Ethical approval for the study was obtained from the Institutional Ethics Committee, and all procedures were carried out in accordance with the principles of the Declaration of Helsinki.
Patients were eligible for inclusion if they underwent emergency surgery for ovarian torsion, ovarian cyst rupture, or ruptured tubal ectopic pregnancy. These 3 conditions were selected because they represent common causes of emergency gynecologic surgery and frequently require urgent operative decision-making. Patients were excluded if they underwent elective gynecologic surgery, obstetric procedures other than surgery for ruptured ectopic pregnancy, had incomplete medical records, lacked documentation regarding surgical timing, or had a final diagnosis outside the 3 predefined emergency gynecologic conditions. The final study population consisted of 386 patients, including 69 patients with ovarian torsion, 77 patients with ovarian cyst rupture, and 240 patients with ruptured ectopic pregnancy.
The final diagnosis was based on operative findings, supported by preoperative clinical, laboratory, and imaging findings when available. Ovarian torsion was defined by intraoperative confirmation of adnexal twisting. Ovarian cyst rupture was defined by operative evidence of a ruptured ovarian cyst with hemoperitoneum or intraperitoneal fluid and no alternative surgical diagnosis. Ruptured tubal ectopic pregnancy was defined by operative identification of tubal ectopic pregnancy with rupture and/or hemoperitoneum, supported by β-human chorionic gonadotropin (hCG) testing and preoperative ultrasonography.
The decision to proceed with emergency surgery was based on clinical urgency, including hemodynamic instability, suspected or confirmed hemoperitoneum, persistent severe pelvic pain, suspected ovarian torsion, ruptured ectopic pregnancy, or failure of conservative management. Stable patients without signs of ongoing bleeding, hemodynamic instability, or urgent surgical pathology could be observed or scheduled according to clinical judgment.
In our institution, emergency gynecologic surgeries are performed under the supervision or direct involvement of an attending gynecologist, and residents do not operate independently without attending oversight.
Patients were divided into 2 groups according to the timing of surgery. Working hours were defined as surgeries performed on weekdays between 8 am and 4:30 pm. Off-hours were defined as surgeries performed after 4:30 pm on weekdays, during nighttime, on weekends, or during holidays. This classification was used consistently for each diagnostic subgroup.
Data were obtained from institutional medical records, operative notes, anesthesia records, laboratory results, and postoperative follow-up documentation. The recorded variables included age, body mass index, gravida, parity, previous abdominal surgery, comorbidity, surgical approach, operative time, intraoperative complications, hemoglobin decrease, length of hospital stay, transfusion requirement, postoperative complications, and reoperation. Surgical approach was categorized as laparoscopic, Pfannenstiel laparotomy, midline laparotomy, or conversion from laparoscopy to laparotomy.
The primary outcome was the comparison of perioperative outcomes between working-hours and off-hours surgery within each diagnostic group. These outcomes included operative time, intraoperative complications, hemoglobin decrease, transfusion requirement, hospital stay, postoperative complications, and reoperation. The secondary outcome was the annual trend in surgical approach over the study period, with particular attention to the proportion of procedures performed laparoscopically. For this analysis, all included emergency gynecologic surgeries were grouped by year, and the annual numbers and proportions of laparoscopic surgery, Pfannenstiel laparotomy, midline laparotomy, and conversion were calculated. Because the study period ended on October 1, 2025, data for 2025 represented the first 9 months of that year.
Statistical analyses were performed using SPSS Statistics for Windows, version 24.0 (IBM Corp., Armonk, NY, USA). The distribution of continuous variables was assessed using visual methods and normality tests. Continuous variables with normal distribution were expressed as mean ± standard deviation and compared using the independent-samples t test. Non-normally distributed continuous variables were expressed as median [interquartile range] and compared using the Mann–Whitney U test. Categorical variables were expressed as number and percentage, and comparisons were performed using the χ2 test or Fisher’s exact test, as appropriate. In addition, multivariable linear regression analyses were performed within each diagnostic group to evaluate the association of off-hours surgery with operative time and, separately, length of hospital stay. In these models, operative time and length of hospital stay were entered as dependent variables, while surgical timing was entered as the main exposure variable. Models were adjusted for age, body mass index, previous abdominal surgery, comorbidity, and surgical approach. Surgical approach was entered as laparoscopic versus nonlaparoscopic because midline laparotomy and conversion were uncommon. Temporal trends in the proportion of laparoscopic procedures were assessed using the linear-by-linear association test. A binary logistic regression model was also used to explore factors associated with laparoscopic surgery, including year of surgery, diagnosis, body mass index, previous abdominal surgery, off-hours status, and comorbidity. All analyses were 2-sided, and a P-value of <.05 was considered statistically significant.
RESULTS
A total of 386 patients who underwent emergency gynecologic surgery were included in the study. Of these, 69 patients underwent surgery for ovarian torsion, 77 for ovarian cyst rupture, and 240 for ruptured tubal ectopic pregnancy. Overall, 91 procedures were performed during working hours and 295 during off-hours. The overall distribution of surgical approach was 192 laparoscopic procedures, 187 Pfannenstiel laparotomies, 4 midline laparotomies, and 3 conversions from laparoscopy to laparotomy.
Among patients with ovarian torsion, 15 underwent surgery during working hours and 54 during off-hours. Baseline characteristics were comparable between the 2 groups, including age, body mass index, gravida, parity, previous abdominal surgery, and comorbidity. The distribution of surgical approach also did not differ significantly between groups. Laparoscopy was performed in 6 patients (40.0%) during working hours and in 28 patients (51.9%) during off-hours. Pfannenstiel laparotomy was performed in 8 patients (53.3%) and 23 patients (42.6%), respectively. Midline laparotomy was used in 1 patient in each group, and conversion from laparoscopy to laparotomy occurred in 2 patients in the off-hours group. Operative time was numerically longer during off-hours, but this difference was not statistically significant: 78 [60–105] minutes versus 60 [45–105] minutes, P = .122. Hemoglobin decrease, hospital stay, transfusion requirement, intraoperative complications, postoperative complications, and reoperation rates were similar between the groups. Two intraoperative complications were observed in the ovarian torsion cohort, both corresponding to conversion from laparoscopy to laparotomy. One postoperative complication occurred, namely trocar-site herniation, and this patient required reoperation (Table 1).
Table 1.
Comparison of Ovarian Torsion Cases According to Working Hours Status
| Working Hours (n = 15) | Off-Hours (n = 54) | P-Value | |
|---|---|---|---|
| Age, years | 27 ± 6.14 | 30 ± 7.48 | .159 |
| BMI, kg/m2 | 24.97 [24.24–25.60] | 25.15 [24.88–25.41] | .517 |
| Gravida | 0 [0–2] | 1 [0–2] | .198 |
| Parity | 0 [0–1] | 0.5 [0–1.25] | .137 |
| Previous abdominal surgery | 3 (20.0%) | 17 (31.5%) | .526 |
| Comorbidity | 1 (6.7%) | 4 (7.4%) | 1.000 |
| Surgical approach | .546 | ||
| Laparoscopic | 6 (40.0%) | 28 (51.9%) | |
| Pfannenstiel | 8 (53.3%) | 23 (42.6%) | |
| Midline | 1 (6.7%) | 1 (1.9%) | |
| Conversion | 0 (0%) | 2 (3.7%) | |
| Operation time, minutes | 60 [45–105] | 78 [60–105] | .122 |
| Intraoperative complication | 0 (0%) | 2 (3.7%) | 1.000 |
| Hemoglobin decrease, g/dL | 1.95 ± 1.01 | 1.64 ± 1.01 | .288 |
| Hospital stay, hours | 72 [48–76] | 48 [44–72] | .088 |
| Transfusion requirement | 1 (6.7%) | 4 (7.4%) | 1.000 |
| Postoperative complication | 0 (0%) | 1 (1.9%) | 1.000 |
| Reoperation | 0 (0%) | 1 (1.9%) | 1.000 |
Abbreviation: BMI, body mass index.
Among patients with ovarian cyst rupture, 19 underwent surgery during working hours and 58 during off-hours. Age, body mass index, gravida, parity, previous abdominal surgery, and comorbidity did not statistically differ between groups. Surgical approach was also comparable. Laparoscopy was performed in 8 patients (42.1%) during working hours and in 28 patients (48.3%) during off-hours, while Pfannenstiel laparotomy was performed in 10 patients (52.6%) and 29 patients (50.0%), respectively. One patient in each group underwent midline laparotomy, and no conversions occurred in this cohort. Operative time, hemoglobin decrease, hospital stay, and transfusion requirement did not differ significantly between working-hours and off-hours groups. No intraoperative complications, postoperative complications, or reoperations were observed among patients with ovarian cyst rupture (Table 2).
Table 2.
Comparison of Ovarian Cyst Rupture Cases According to Working Hours Status
| Working Hours (n = 19) | Off-Hours (n = 58) | P-Value | |
|---|---|---|---|
| Age, years | 29.32 ± 6.82 | 26.31 ± 6.22 | .078 |
| BMI, kg/m2 | 24.97 [22.03–26.49] | 24.88 [23.89–25.32] | .869 |
| Gravida | 2 [0–3] | 1 [0–2] | .124 |
| Parity | 1 [0–2] | 0 [0–2] | .378 |
| Previous abdominal surgery | 4 (21.1%) | 17 (29.3%) | .483 |
| Comorbidity | 0 (0%) | 4 (6.9%) | .567 |
| Surgical approach | .594 | ||
| Laparoscopic | 8 (42.1%) | 28 (48.3%) | |
| Pfannenstiel | 10 (52.6%) | 29 (50.0%) | |
| Midline | 1 (5.3%) | 1 (1.7%) | |
| Conversion | 0 (0%) | 0 (0%) | |
| Operation time, minutes | 69 [49–110] | 65 [60–100.50] | .608 |
| Intraoperative complication | 0 (0%) | 0 (0%) | 1.000 |
| Hemoglobin decrease, g/dL | 1.60 [0.70–2.10] | 1.45 [0.30–2.40] | .566 |
| Hospital stay, hours | 48 [24–71] | 44.5 [31.75–52] | .740 |
| Transfusion requirement | 7 (36.8%) | 16 (27.6%) | .444 |
| Postoperative complication | 0 (0%) | 0 (0%) | 1.000 |
| Reoperation | 0 (0%) | 0 (0%) | 1.000 |
Abbreviation: BMI, body mass index.
Among patients with ruptured tubal ectopic pregnancy, 57 underwent surgery during working hours and 183 during off-hours. Demographic and clinical characteristics, including age, body mass index, gravida, parity, previous abdominal surgery, and comorbidity, were similar between groups. The distribution of surgical approach did not differ significantly. Laparoscopy was performed in 27 patients (47.4%) during working hours and in 95 patients (51.9%) during off-hours, while Pfannenstiel laparotomy was performed in 30 patients (52.6%) and 87 patients (47.5%), respectively. One conversion from laparoscopy to laparotomy occurred in the off-hours group. Operative time was significantly longer in the off-hours group compared with the working-hours group: 69 [60–96] minutes versus 60 [45–80] minutes, P = .016. In contrast, hemoglobin decrease, hospital stay, transfusion requirement, intraoperative complications, postoperative complications, and reoperation rates were comparable between groups. In this cohort, intraoperative complications included one conversion from laparoscopy to laparotomy, one bowel injury, and one case of massive bleeding. Postoperative complications included 2 wound infections, one pelvic abscess, and one atelectasis. No reoperations were required in the ruptured tubal ectopic pregnancy cohort (Table 3).
Table 3.
Comparison of Ruptured Tubal Ectopic Pregnancy Cases According to Working Hours Status
| Working Hours (n = 57) | Off-Hours (n = 183) | P-Value | |
|---|---|---|---|
| Age, years | 31 [27.5–37] | 31 [26–35] | .323 |
| BMI, kg/m2 | 24.37 ± 2.53 | 24.02 ± 1.98 | .274 |
| Gravida | 3 [2–4] | 3 [2–4] | .547 |
| Parity | 1 [1–2] | 1 [0–2] | .733 |
| Previous abdominal surgery | 22 (38.6%) | 66 (36.1%) | .729 |
| Comorbidity | 1 (1.8%) | 7 (3.8%) | .684 |
| Surgical approach | .698 | ||
| Laparoscopic | 27 (47.4%) | 95 (51.9%) | |
| Pfannenstiel | 30 (52.6%) | 87 (47.5%) | |
| Midline | 0 (0%) | 0 (0%) | |
| Conversion | 0 (0%) | 1 (0.5%) | |
| Operation time, minutes | 60 [45–80] | 69 [60–96] | .016 |
| Intraoperative complication | 1 (1.8%) | 2 (1.1%) | .558 |
| Hemoglobin decrease, g/dL | 1.3 [0.85–1.95] | 1.4 [0.8–2.0] | .946 |
| Hospital stay, hours | 48 [48–71.5] | 48 [45–72] | .372 |
| Transfusion requirement | 12 (21.1%) | 32 (17.5%) | .543 |
| Postoperative complication | 1 (1.8%) | 3 (1.6%) | 1.000 |
| Reoperation | 0 (0%) | 0 (0%) | 1.000 |
Abbreviation: BMI, body mass index.
In multivariable linear regression analyses adjusted for age, body mass index, previous abdominal surgery, comorbidity, and surgical approach, off-hours surgery was not independently associated with operative time or length of hospital stay in ovarian torsion or ovarian cyst rupture cases. In ruptured tubal ectopic pregnancy cases, off-hours surgery remained independently associated with longer operative time (adjusted β = 12.26 minutes, 95% CI 3.14 to 21.38, P = .009), but was not associated with length of hospital stay (adjusted β = 0.05 hours, 95% CI –5.96 to 6.05, P = .988). The adjusted results are shown in Table 4.
Table 4.
Multivariable Linear Regression Analysis for Operative Time and Length of Hospital Stay
| Diagnostic Group | Outcome | Adjusted β for Off-Hours | 95% CI | P-Value |
|---|---|---|---|---|
| Ovarian torsion | Operative time, minutes | −1.04 | −24.47 to 22.38 | .929 |
| Ovarian torsion | Hospital stay, hours | −4.37 | −25.54 to 16.80 | .681 |
| Ovarian cyst rupture | Operative time, minutes | −4.29 | −24.90 to 16.33 | .680 |
| Ovarian cyst rupture | Hospital stay, hours | −3.44 | −18.74 to 11.87 | .656 |
| Ruptured tubal EP | Operative time, minutes | 12.26 | 3.14 to 21.38 | .009 |
| Ruptured tubal EP | Hospital stay, hours | 0.05 | −5.96 to 6.05 | .988 |
Abbreviation: EP, ectopic pregnancy. β values represent adjusted mean differences for off-hours surgery compared with working-hours surgery. Models were adjusted for age, body mass index, previous abdominal surgery, comorbidity, and surgical approach. Surgical approach was categorized as laparoscopic versus nonlaparoscopic.
Annual analysis of surgical approach demonstrated a marked shift toward laparoscopy over the study period. The proportion of laparoscopic procedures increased from 17.9% in 2020 to 43.2% in 2021, 55.2% in 2022, 56.4% in 2023, 85.7% in 2024, and 90.0% in the first 9 months of 2025. The temporal increase in laparoscopy was statistically significant (linear-by-linear association, P ≤ .001). In binary logistic regression analysis, year of surgery was independently associated with laparoscopic surgery (adjusted OR = 1.92 per calendar year, 95% CI 1.62 to 2.27, P ≤ .001), whereas diagnosis, body mass index, previous abdominal surgery, off-hours status, and comorbidity were not. In parallel, the proportion of Pfannenstiel laparotomy decreased from 81.0% in 2020 to 6.7% in 2025. Midline laparotomy and conversion from laparoscopy to laparotomy remained uncommon throughout the study period. This annual change in surgical approach is shown in Figure 1.
Figure 1.
Trend in surgical approach in emergency gynecologic surgery: a shift toward laparoscopy. Annual distribution of surgical approaches from 2020 to 2025. Data for 2025 represent the first 9 months. Conversion indicates laparoscopy-to-laparotomy conversion.
DISCUSSION
In this retrospective cohort study, perioperative outcomes were largely comparable between emergency gynecologic surgeries performed during working hours and those performed during off-hours. Across ovarian torsion, ovarian cyst rupture, and ruptured tubal ectopic pregnancy, no significant differences were observed in hemoglobin decrease, transfusion requirement, length of hospital stay, intraoperative or postoperative complications, or reoperation rates. The only significant difference was a longer operative time among off-hours ruptured tubal ectopic pregnancy cases. In addition, we observed a marked increase in the use of laparoscopy during the study period, rising from 17.9% in 2020 to 90.0% in the first 9 months of 2025.
The relationship between surgical timing and outcomes remains controversial. Although previous studies have reported higher morbidity and mortality associated with after-hours surgery, these findings have not been consistent across specialties or clinical settings.2–5,18,19 Our results suggest that emergency gynecologic surgery can be performed safely outside routine working hours when institutional resources, surgical expertise, and operating room availability are adequate. These findings are consistent with studies showing comparable outcomes between daytime and after-hours surgery for selected urgent procedures.6–8
The longer operative time observed in off-hours ruptured tubal ectopic pregnancy cases persisted after adjustment for available baseline and surgical variables. However, detailed acuity-related variables such as preoperative hemodynamic status, shock index, β-hCG level, ultrasound findings, and estimated hemoperitoneum volume were not incorporated into the present analysis. Therefore, residual confounding by disease severity or operative complexity remains possible. Importantly, although this difference was statistically significant, the absolute difference in median operative time was approximately 9 minutes in the unadjusted comparison and was not accompanied by increased transfusion requirements, complications, reoperations, or prolonged hospitalization. Therefore, its clinical significance appears limited.
The low overall complication rate observed in this cohort is reassuring. Major adverse events were uncommon across all diagnostic groups, and no complications occurred in patients undergoing surgery for ovarian cyst rupture. However, the small number of complications limits statistical power and precludes identification of independent predictors of adverse outcomes.
The marked increase in laparoscopy was another important finding of this study. This trend likely reflects growing surgeon experience, improved availability of laparoscopic equipment, and broader institutional acceptance of minimally invasive surgery in emergency gynecologic practice. However, this finding should be interpreted cautiously because the study period began during the COVID-19 pandemic, when concerns regarding pneumoperitoneum, surgical smoke, and potential aerosol exposure may have influenced the use of laparoscopy, particularly in 2020. Overall, this descriptive trend supports the feasibility of minimally invasive management in acute gynecologic emergencies, but it should not be interpreted as evidence of a single causal factor driving the change in surgical approach.
This study has several strengths. It focused on 3 common emergency gynecologic conditions and analyzed each diagnosis separately, thereby reducing clinical heterogeneity. Additionally, the study evaluated both the effect of surgical timing and temporal changes in surgical approach, providing insight into evolving emergency gynecologic practice.
Several limitations should also be acknowledged. The retrospective single-center design introduces the potential for selection bias and limits generalizability. The low frequency of complications restricted statistical power and prevented multivariable modeling for adverse outcomes. Off-hours procedures were analyzed as a single group, although evenings, nights, weekends, and holidays may differ in staffing and resource availability. Finally, factors such as detailed disease severity measures, surgeon experience, staffing patterns, team composition, fatigue, and institutional resource availability were not incorporated into the present analysis and could have influenced outcomes.
In conclusion, emergency gynecologic surgeries performed during off-hours demonstrated perioperative outcomes comparable to those performed during working hours. Although operative time was longer for off-hours ruptured tubal ectopic pregnancy cases, no differences were observed in complications, transfusions, reoperations, or length of stay. The marked increase in laparoscopic surgery over time highlights the growing integration of minimally invasive techniques into emergency gynecologic care. These findings support the feasibility of safe off-hours emergency gynecologic surgery in experienced centers; however, the temporal trend toward laparoscopy should be interpreted cautiously because of potential temporal and institutional confounders.
Footnotes
Ethics approval was obtained from the Tepecik Training and Research Hospital Ethics Committee (Approval No: 2025/10-12), and the study was performed in line with the principles of the Declaration of Helsinki.
Conflict of interests: none.
Funding sources: none
Disclosure: none.
Contributor Information
Alaattin Karabulut, Department of Obstetrics and Gynecology, University of Health Sciences Tepecik Training and Research Hospital, Izmir, Türkiye..
Sercan Kantarcı, Department of Obstetrics and Gynecology, University of Health Sciences Tepecik Training and Research Hospital, Izmir, Türkiye..
Uğurcan Dağlı, Department of Obstetrics and Gynecology, University of Health Sciences Tepecik Training and Research Hospital, Izmir, Türkiye..
Didem Sezen, Department of Obstetrics and Gynecology, University of Health Sciences Tepecik Training and Research Hospital, Izmir, Türkiye..
Elif Atıcı, Department of Obstetrics and Gynecology, University of Health Sciences Tepecik Training and Research Hospital, Izmir, Türkiye..
Abdurrahman Hamdi İnan, Department of Obstetrics and Gynecology, University of Health Sciences Tepecik Training and Research Hospital, Izmir, Türkiye..
Mehmet Özer, Department of Obstetrics and Gynecology, University of Health Sciences Tepecik Training and Research Hospital, Izmir, Türkiye..
Mehmet Özeren, Department of Obstetrics and Gynecology, University of Health Sciences Tepecik Training and Research Hospital, Izmir, Türkiye..
References:
- 1.McWilliams GD, Hill MJ, Dietrich CS., 3rd.Gynecologic emergencies. Surg Clin North Am. 2008;88(2):265–283, vi. [DOI] [PubMed] [Google Scholar]
- 2.Kelz RR, Freeman KM, Hosokawa PW, et al. Time of day is associated with postoperative morbidity: an analysis of the national surgical quality improvement program data. Ann Surg. 2008;247(3):544–552. [DOI] [PubMed] [Google Scholar]
- 3.Aylin P, Alexandrescu R, Jen MH, Mayer EK, Bottle A. Day of week of procedure and 30 day mortality for elective surgery: retrospective analysis of hospital episode statistics. BMJ. 2013;346:f2424. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Yang N, Elmatite WM, Elgallad A, Gajdos C, Pourafkari L, Nader ND. Patient outcomes related to the daytime versus after-hours surgery: a meta-analysis. J Clin Anesth. 2019;54:13–18. [DOI] [PubMed] [Google Scholar]
- 5.Cortegiani A, Ippolito M, Misseri G, et al. Association between night/after-hours surgery and mortality: a systematic review and meta-analysis. Br J Anaesth. 2020;124(5):623–637. [DOI] [PubMed] [Google Scholar]
- 6.Chan YM, Tang N, Chow SKH. Surgical outcome of daytime and out-of-hours surgery for elderly patients with hip fracture. Hong Kong Med J. 2018;24(1):32–37. [DOI] [PubMed] [Google Scholar]
- 7.Bauer TM, Pienta MJ, Wu X, et al. Michigan Society of Thoracic and Cardiovascular Surgeons Quality Collaborative and The Video Assessment of CaRdiac Surgery QualITY (VARSITY) Surgery Investigators. Outcomes of nonemergency cardiac surgery after overnight operative workload: a statewide experience. JTCVS Open. 2024;20:101–111. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Oulasvirta E, Knuutinen O, Tommiska P, Kivisaari R, Raj R; FINISH study group. Night-time versus daytime surgical outcomes in chronic subdural hematomas: a post hoc analysis of the FINISH randomized trial. Acta Neurochir (Wien). 2024;166(1):421. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Ricci WM, Gallagher B, Brandt A, Schwappach J, Tucker M, Leighton R. Is after-hours orthopaedic surgery associated with adverse outcomes? A prospective comparative study. J Bone Joint Surg Am. 2009;91(9):2067–2072. [DOI] [PubMed] [Google Scholar]
- 10.Kshirsagar A, Kannur S. Impact of nighttime emergency surgeries on patients’ outcome: a prospective study. Niger J Surg. 2020;26(2):99–103. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Barlow AP, Wilkinson DA, Wordsworth M, Eyre-Brook IA. An emergency daytime theatre list: utilisation and impact on clinical practice. Ann R Coll Surg Engl. 1993;75(6):441–444. [PMC free article] [PubMed] [Google Scholar]
- 12.Hu H, Goh A. The impact of surgical start time on complications in gynaecological surgery: a retrospective cohort study. Gynecol Pelvic Med. 2022;5(0):23. [Google Scholar]
- 13.Slaughter KN, Frumovitz M, Schmeler KM, et al. Minimally invasive surgery for endometrial cancer: does operative start time impact surgical and oncologic outcomes? Gynecol Oncol. 2014;134(2):248–252. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Lo LM, Chang SD, Horng SG, Yang TY, Lee CL, Liang CC. Laparoscopy versus laparotomy for surgical intervention of ovarian torsion. J Obstet Gynaecol Res. 2008;34(6):1020–1025. [DOI] [PubMed] [Google Scholar]
- 15.Promecene PA. Laparoscopy in gynecologic emergencies. Surg Innov. 2002;9(1):64–75. [PubMed] [Google Scholar]
- 16.Keyif B, Yurtçu E, Yıldız SM, Boğan M. Acil Servis Jinekolojik Konsültasyonların 12 Yıllık Retrospektif İncelemesi: Başvuru Zamanının Klinik Sonuçlara Etkisi. Jinekoloji. Obstetrik ve Neonatoloji Tıp Derg. 2025;22(3):359–366. [Google Scholar]
- 17.Fuentes MN, Rodríguez-Oliver A, Naveiro Rilo JC, Paredes AG, Aguilar Romero MT, Parra JF. Complications of laparoscopic gynecologic surgery. JSLS. 2014;18(3):e2014.00058. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Oh TK, Song IA. Outcomes of after-hours surgeries performed under general anaesthesia: a South Korean nationwide cohort study. Anaesthesia. 2025;80(6):645–651. [DOI] [PubMed] [Google Scholar]
- 19.Pasupathy D, Wood AM, Pell JP, Fleming M, Smith GCS. Time of birth and risk of neonatal death at term: retrospective cohort study. BMJ. 2010;341:c3498. [DOI] [PMC free article] [PubMed] [Google Scholar]