Timely Intervention, Lasting Impact: Are We Learning? A Retrospective Insight into Perimortem Caesarean Sections and the Critical Value of Time

Objective: To evaluate the critical role of time in perimortem caesarean section (PMCS) outcomes and reinforce simulation- based preparedness. Design: Retrospective observational cohort study. Setting: Tertiary referral centre in Northern India. Population: Pregnant women with cardiac arrest >20 weeks’ gestation from Jan 2020 to Dec 2024. Methods: Retrospective chart review of 20 cases undergoing PMCS. Time from cardiac arrest to surgical intervention, survival outcomes, comorbidities, and gestational age were analysed. Outcomes were stratified based on early ( 5 min) intervention. Main Outcome Measures: Maternal and fetal survival rates in relation to intervention timing. Results: Early intervention improved maternal survival (28.6% vs 15.4%) and fetal survival (100% vs 61.5%). Timing was significantly associated with fetal outcome (AUC 0.733), though maternal outcomes were influenced by multiple factors. Conclusions: Early PMCS within 5 minutes significantly enhances fetal outcomes and potentially maternal outcomes. Simulation drills and dedicated emergency teams are critical in bridging the preparedness gap.

Cardiac arrest during pregnancy is a very challenging clinical scenario with the lives of both mother and fetus at risk. Cardiac arrest during antenatal hospitalization was reported to be approximately 1 in 9000 admissions in the United States [1]. Due to the limited availability of maternal data registries and inadequate reporting in India, there is insufficient information about the precise prevalence of such events. This is a rare event that most obstetricians may encounter only once in their lifetime, making it an apprehensive and challenging task to promptly perform perimortem cesarean section (PMCS) as part of resuscitation. Although the resuscitation algorithms during pregnancy are the same as in nonpregnant individuals, there are a few important anatomical and physiological interpretations to be kept in mind while managing these patients for example displacing the gravid uterus manually to improve venous return, etc [2]. However, the key distinguishing step is the timely initiation of PMCS in these patients. Delay in this might have calamitous consequences for the families. Ideally, PMCS should be initiated within 4 minutes of failure to return of spontaneous circulation (ROSC) and this is defined as ‘Cesarean delivery being initiated after the initiation of cardiopulmonary resuscitation’ [3]. Perimortem cesarean section is now being referred to as a maternal resuscitative measure rather than the earlier references as a fetal-centric measure. Therefore, PMCS is better pronounced as resuscitative hys- terotomy (RH) as suggested in the literature [4]. In this study, we will evaluate the details of 20 RH being conducted at our center in the last 5 years to assess the impact of timely intervention on maternal and fetal mortality. This study will help to create awareness about this undervalued intervention during maternal resuscitation. It will encourage emergency departments at a tertiary referral center to create simulation 1 Posted on 17 Apr 2025 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.174487478.86130074/v1 — This is a preprint and has not been peer-reviewed. Data may be preliminary. models and conduct mock drills to further enhance the outcomes. Through this study, we would like to pro- pose that all high-volume tertiary referral hospitals must have a dedicated team PRISM (P erimortemR esuscitation and I mmediate S urgicalM anagement) trained to handle such emergencies effectively.

Study Design and Setting This is a retrospective descriptive cohort study conducted at a tertiary care center in northern India. This institute is a high-volume referral center for high-risk obstetrics patients from all over northern India. Study Population This study included all women who underwent perimortem cesarean delivery (PMCD) following maternal cardiac arrest between January 2020 and December 2024 at our institute. Inclusion Criteria Documented cardiac arrest at a gestational age of > 20 weeks. Those who underwent perimortem cesarean delivery at the time of maternal resuscitation. Exclusion Criteria • Incomplete medical records. • Gestational age < 20 weeks. • Pregnant females brought dead to the casualty. The clinical team immediately assessed patients presenting to the emergency department. Upon arrival, if the Modified Early Warning Score (MEWS) (table 1) was greater than or equal to 4, the rapid response team was activated.[5] Immediate resuscitative measures, including airway management, chest compressions, and administration of appropriate medications, were initiated in line with protocols for non-pregnant patients. Throughout resuscitation, continuous left uterine displacement was maintained by an assistant to optimize maternal hemodynamics and prevent aortocaval compression. If there was no return of spontaneous circulation (ROSC) within 4 minutes of initiating resuscitation, a perimortem cesarean section was performed at the site of resuscitation in the emergency department. In this study, we performed PMCD via Pfannenstiel incision in all patients. Data on the precise timing of interventions and outcomes were meticulously recorded for each case. Data Collection A comprehensive retrospective review of medical records was performed. Data was collected using a stan- dardized, predesigned proforma that included: Demographic information Maternal age Gravidity and parity Clinical parameters • Gestational age • Cause of maternal morbidity • Time interval between cardiac arrest and cesarean section Perimortem caesarean section details Maternal and fetal outcomes as post-procedure maternal and newborn survival. Statistical analysis 2 Posted on 17 Apr 2025 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.174487478.86130074/v1 — This is a preprint and has not been peer-reviewed. Data may be preliminary. Statistical analysis was done using Microsoft Excel, where mean age, frequency of early ( 4 minutes) cesarean was calculated. Fischer exact test was used to drive a statistical correlation of the time interval between diagnosis and cesarean section and maternal and fetal outcomes in the form of survival. Ethical considerations The study was approved by the Institutional Ethics Committee and due to the retrospective nature of the study and anonymized data collection, a waiver of individual patient consent was obtained.

Patient characteristics This study included 20 patients. All patients were received in the obstetric emergency and managed individ- ually as per the clinical circumstances. The mean maternal age was 32, ranging from 19 to 42 years. Eight (40%) patients were primigravida and 12 (60%) were multigravida. The mean gestational age at the time of maternal cardiac arrest was 33.8 weeks (SD 3.2 weeks, range 26-38 weeks). Age-related patterns: Mothers aged 35 years and older showed the highest maternal survival rate (28.6%), followed by those aged 25-34 years (18.2%). Interestingly, fetal survival was 100% in both the youngest ( <25 years) and oldest ([?]35 years) age groups, while it was lower (54.5%) in the middle age group. However, the maternal age shows no significant impact on the survival rates of both mother and fetus. Gestational age relationships analysis: Patients were categorized by gestational age at the time of cardiac arrest as follows: * Early preterm ( <32 weeks): 4 cases (20%) * Late preterm (32–36 weeks): 11 cases (55%) * Term pregnancies ([?]37 weeks): 5 cases (25%) There was no statistically significant difference in maternal and fetal survival outcomes across these gesta- tional age groups (Fisher’s exact test, p = 0.44). Mothers presenting at early gestational age ( 37 weeks. Notably, fetal sur- vival was 100% in early preterm pregnancies. Figure 1 depicts fetal survival after early intervention across different gestational age groups. Table 1 illustrates the maternal survival and early intervention outcomes for different gestational age groups. Comorbidities Comorbid conditions were common among mothers with cardiac arrest. Hypertensive disorders of pregnancy (including pre-eclampsia, eclampsia, and gestational hypertension) were the most frequent, present in 9 (45%) of cases. Other comorbidities included infections (dengue, sepsis, meningitis) in 5 (25%), hemorrhagic shock due to splenic artery aneurysm rupture in 3 (15%), transfusion reactions in 2 (10%), and miscellaneous causes like chronic kidney disease in 1 (5%) patient. Cardiovascular comorbidities show better survival in comparison to infectious complications. Timing of Intervention and Survival Outcomes Early intervention (PMCD within 5 minutes of maternal cardiac arrest) was associated with better survival outcomes. Maternal survival was higher in the early intervention group (28.6%) compared to the late intervention group (15.4%). Fetal survival was 100% with early intervention, compared to 61.5% with later intervention. However, these differences were not statistically significant (Table 2). 3 Posted on 17 Apr 2025 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.174487478.86130074/v1 — This is a preprint and has not been peer-reviewed. Data may be preliminary. The maternal and fetal survival rates decline as the interval between the maternal cardiac arrest and the resuscitative hysterotomy increases beyond 4 minutes,t as shown in Figure 2. The receiver operating char- acteristic (ROC) analysis, as shown in Figure 3, indicates that the time interval between maternal cardiac arrest and hysterotomy has a moderate ability to predict maternal survival outcomes (AUC = 0.594) and a strong ability to predict fetal survival outcomes (AUC = 0.733).

The perimortem cesarean section (PMCS) is the surgical procedure done to deliver a fetus at the time of maternal cardiac arrest. This procedure’s performance was known to exist since 715 BC when it was believed that no child should be buried with their mother.[6] Since then, indications have been developing to perform this procedure with the largest landmark literature review by Katz et al. [3] Out of 269 cases, 188 (70%) infants survived if delivered within 5 minutes from the death of the mother. Thus, it was suggested to initiate the procedure within 4 minutes of failure to return of spontaneous circulation (ROSC) and deliver the fetus by 5 minutes. The justification for performing PMCS was that reducing the volume of the uterus alleviates the compression on the inferior vena cava (IVC), thus increasing the venous return and subsequently increasing the cardiac output in these patients. This procedure also increases the pulmonary functional residual capacity of the mother by decreasing the diaphragmatic elevation. This procedure, being an integral part of maternal resuscitation in the emergency department, can also be named as resuscitative hysterotomy. At the end of this procedure, cardiopulmonary resuscitation becomes more effective with early return of spontaneous circulation (ROSC). [7] The incidence of cardiac arrest during pregnancy is very low, occurring in 1 in 12,500 pregnancies.[8] Due to this, very few case series are published in the literature, highlighting the importance of timing in achieving positive maternal and fetal outcomes. Principal findings: This study demonstrates the details of 20 patients who underwent perimortem cesarean section after maternal cardiac arrest. This study highlights that the cardiovascular causes of arrest had better outcomes after early intervention as compared to that of sepsis-induced comorbidity. This study strongly suggests that the timing of intervention has an important impact on the survival of both mother and fetus. Although the difference was not statistically significant, this study suggests that early intervention is crucial in improving the outcomes. Most importantly this study demonstrates that the relationship between time to intervention and fetal survival is stronger than for maternal survival as shown by the AUC of 0.733 for fetal outcome as compared to the AUC of 0.594 for maternal outcome. The reason for this is that the maternal outcome is influenced by multiple factors beyond the intervention timing alone including the severity of the associated comorbidities. The lack of statistical significance is likely due to the small sample size rather than a lack of true effect. Earlier gestational ages showed slightly better maternal outcomes. Mothers presenting at less than 32 weeks had a 25% survival rate, compared to 20% for 32-36 weeks and 16.7% for [?]37 weeks. The reason for this can be that the mother with gestational age less than 32 weeks had the highest rate of early intervention (75%). Fetal survival was excellent (100%) across all gestational age groups when the PMCD was performed within 5 minutes of cardiac arrest, suggesting that earlier presentation might allow for better preparation and management of both maternal and fetal complications and also emphasizes the importance of timely intervention. Therefore, early gestational age or immaturity alone should not preclude us from early intervention. In this study, the maternal survival was low, which is consistent with the data in the literature. At the time of cardiac arrest, mothers are more vulnerable as compared to fetus because of the physiological peripheral vasodilatation maintaining the uteroplacental blood flow to a greater extent.[9] Comparison with existent literature: Our results were consistent with the existing recommendations for rapid delivery following maternal cardiac arrest. The scientific statement from the American Heart Association states that the perimortem cesarean 4 Posted on 17 Apr 2025 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.174487478.86130074/v1 — This is a preprint and has not been peer-reviewed. Data may be preliminary. section should be considered as the core part of maternal resuscitation. They emphasized that the procedure should be performed at the site of arrest without wasting time in shifting the patient to the operation theatre. Mothers are more vulnerable to hypoxic brain injury as compared to non-pregnant patients and can happen as early as within 4 minutes of cardiac arrest. Therefore, it is recommended that PMCD should begin at 4 minutes to effect delivery at 5 minutes after failure to ROSC. [9,10] In our study, only 7 (35%) patients had early perimortem cesarean delivery ( <5 minutes). Postcode analysis and debriefing revealed that the delay in initiating the procedure is mainly due to reluctance, unawareness, and lack of confidence in performing the procedure. In comparison, McDonell [11] recommends that each tertiary care center must have regular training modules to involve all required staff including obstetricians in frequent mock drills to help them cross this mental barrier. Frequent audits should be conducted to measure the resuscitation skills of the obstetricians and other team members as suggested by the Royal College of Obstetricians and Gynecologists. [12] At our institution, all the PMCDs were performed via the Pfannenstiel incision contrary to the vertical midline incision as recommended in the literature. [7] We preferred this incision to reduce our anxiety and prevent delay in performing the procedure as we are more familiar with the Pfannenstiel type of incision. We have not faced any difficulty in performing the procedure via this incision. In our study maternal survival rate was poor (20%) and the overall fetal survival rate was 75% with 100% survival among those who had early PMCD. This is consistent with the nationwide assessment of all PMCD cases done in the Netherlands from 1993 to 2008. In their study, the maternal case fatality rate was high with only 17% surviving after PMCD and the fetal survival rate was 42% in the PMCD group.[13] In our study, figure 2 shows that as the time from maternal cardiac arrest increases, maternal and fetal survival decreases which is consistent with the study by Benson MD et al. [14] and the study by Einav S et al clearly stated that the PMCD was beneficial to 31.7% of mothers without any harm to them. [15] Strengths and Limitations Strengths: This study is among the few from India evaluating PMCD outcomes in a real-world tertiary care setting. The inclusion of cases across a broad gestational age spectrum adds valuable insights that we should not hesitate in performing PMCD even in early gestation age.

• The retrospective nature limits the ability to control for confounding variables and may have introduced bias in reporting. • The small sample size reduces statistical power and may under-represent important events. • We did not capture neurological outcomes for neonates, which must also be included as an outcome measure for better assessment rather than only survival. Clinical and future implications: This study emphasized conducting PMCD within 5 minutes of maternal cardiac arrest to have better out- comes irrespective of the gestational age of the patient. This study suggests that the frequent conduction of training and simulation models for obstetrics emergency teams is a way forward to prevent cognitive dissonance at the time of maternal cardiac arrest. We recommend for training and establishing a dedicated PRISM (Perimortem Resuscitation and Immediate Surgical Management) team to handle such emergencies effectively.

Perimortem cesarean section or Resuscitative hysterotomy is a time-sensitive intervention. It should be considered as one of the steps in maternal resuscitation during cardiac arrest. This study highlights the importance of early intervention in improving the survival outcome in both mother and fetus. This study 5 Posted on 17 Apr 2025 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.174487478.86130074/v1 — This is a preprint and has not been peer-reviewed. Data may be preliminary. supports prioritizing rapid intervention regardless of gestational age as prematurity alone should not delay intervention. Training and simulation models will help in creating the desired expert team which will alleviate the horror of performing PMCD at the site of maternal cardiac arrest.

1. Ford ND, DeSisto CL, Galang RR, Kuklina EV, Sperling LS, Ko JY. Cardiac Arrest During Delivery Hospitalization: A Cohort Study. Ann Intern Med. 2023 Apr;176(4):472-479. doi: 10.7326/M22-2750. Epub 2023 Mar 14. PMID: 36913690; PMCID: PMC10264156. 2. Paterson-Brown S, Howell C, editors. The MOET course manual: managing obstetric emergencies and trauma. 3rd ed. Cambridge: Cambridge University Press; 2014. 3. Katz VL, Dotters DJ, Droegemueller W. Perimortem cesarean delivery. Obstet Gynecol. 1986 Oct;68(4):571-6. PMID: 3528956. 4. Lipman SS, Cohen S, Mhyre J, Carvalho B, Einav S, Arafeh J, et al. Challenging the 4- to 5-minute rule: from perimortem cesarean to resuscitative hysterotomy. Am J Obstet Gynecol. 2016 Jul;215(1):129-31. doi: 10.1016/j.ajog.2016.03.043. Epub 2016 Mar 31. PMID: 27040085. 5. Hester J, Youn TS, Trifilio E, Robinson CP, Babi MA, Ameli P et al. The Modified Early Warn- ing Score: A Useful Marker of Neurological Worsening but Unreliable Predictor of Sepsis in the Neurocritically Ill-A Retrospective Cohort Study. Crit Care Explor. 2021 May 18;3(5):e0386. doi: 10.1097/CCE.0000000000000386. PMID: 34036267; PMCID: PMC8133042. 6. Fadel HE. Postmortem and perimortem cesarean section: historical, religious and ethical consid- erations. J IMA. 2011 Dec;43(3):194-200. doi: 10.5915/43-3-7099. PMID: 23610509; PMCID: PMC3516125. 7. Drukker L, Hants Y, Sharon E, Seia HY, Grisaru-Granovsky S. Perimortem cesarean section for ma- ternal and fetal salvage: concise review and protocol. Acta Obstet Gynecol Scand 2014;93:965–72. 8. Rose CH, Faksh A, Traynor KD, Cabrera D, Arendt KW, Brost BC. Challenging the 4- to 5-minute rule: from perimortem cesarean to resuscitative hysterotomy. Am J Obstet Gynecol. 2015 Nov;213(5):653-6, 653.e1. doi: 10.1016/j.ajog.2015.07.019. Epub 2015 Jul 26. PMID: 26212180. 9. Jeejeebhoy FM, Zelop CM, Lipman S, Carvalho B, Joglar J, Mhyre JM, et al; American Heart As- sociation Emergency Cardiovascular Care Committee, Council on Cardiopulmonary, Critical Care, Perioperative and Resuscitation, Council on Cardiovascular Diseases in the Young, and Council on Clinical Cardiology. Cardiac Arrest in Pregnancy: A Scientific Statement from the American Heart Association. Circulation. 2015 Nov 3;132(18):1747-73. doi: 10.1161/CIR.0000000000000300. Epub 2015 Oct 6. PMID: 26443610. 10. Panchal AR, Bartos JA, Caba˜ nas JG, Donnino MW, Drennan IR, Hirsch KG, et al; Adult Basic and Advanced Life Support Writing Group. Part 3: Adult Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2020 Oct 20;142(16 suppl 2):S366-S468. doi: 10.1161/CIR.0000000000000916. Epub 2020 Oct 21. PMID: 33081529. 11. McDonnell NJ. Cardiopulmonary arrest in pregnancy: two case reports of successful outcomes in association with perimortem Caesarean delivery. Br J Anaesth. 2009 Sep;103(3):406-9. doi: 10.1093/bja/aep176. Epub 2009 Jun 26. PMID: 19561013. 12. Chu J, Johnston TA, Geoghegan J; Royal College of Obstetricians and Gynaecologists. Maternal Col- lapse in Pregnancy and the Puerperium: Green-top Guideline No. 56. BJOG. 2020 Apr;127(5):e14-e52. doi: 10.1111/1471-0528.15995. Epub 2019 Dec 17. PMID: 31845507. 13. Dijkman A, Huisman CM, Smit M, Schutte JM, Zwart JJ, van Roosmalen JJ, et al. Cardiac arrest in pregnancy: increasing use of perimortem caesarean section due to emergency skills training? BJOG. 2010 Feb;117(3):282-7. doi: 10.1111/j.1471-0528.2009.02461.x. PMID: 20078586. 14. Benson MD, Padovano A, Bourjeily G, Zhou Y. Maternal collapse: Challenging the four-minute ru- le. EBioMedicine. 2016 Apr;6:253-257. doi: 10.1016/j.ebiom.2016.02.042. Epub 2016 Mar 2. PMID: 27211568; PMCID: PMC4856753. 15. Einav S, Kaufman N, Sela HY. Maternal cardiac arrest and perimortem caesarean delivery: evidence or 6 Posted on 17 Apr 2025 — The copyright holder is the author/funder. All rights reserved. No reuse without permission. — https://doi.org/10.22541/au.174487478.86130074/v1 — This is a preprint and has not been peer-reviewed. Data may be preliminary. expert-based? Resuscitation. 2012 Oct;83(10):1191-200. doi: 10.1016/j.resuscitation.2012.05.005. Epub 2012 May 18. PMID: 22613275. Hosted file bjog figures.docx available at https://authorea.com/users/914149/articles/1287356-timely- intervention-lasting-impact-are-we-learning-a-retrospective-insight-into-perimortem- caesarean-sections-and-the-critical-value-of-time Hosted file tables bjog.docx available at https://authorea.com/users/914149/articles/1287356-timely- intervention-lasting-impact-are-we-learning-a-retrospective-insight-into-perimortem- caesarean-sections-and-the-critical-value-of-time 7