Obstetric Anesthesiology Research

Advancing Obstetric and Perinatal Anesthetic Care

Research Mission Statement

To advance knowledge in the field of obstetric anesthesiology and peripartum care through clinical, epidemiological, and outcomes-based research.

Research Vision Statement

To optimize and personalize maternal care provided by obstetric anesthesiologists.


Our Research Faculty

Our faculty are internationally recognized experts in obstetric anesthesiology. 

We aim to advance the health and well-being of mothers by:

  1. Ensuring each woman obtains high-quality pain relief during and after her delivery.
  2. Identifying approaches for preventing and treating postpartum hemorrhage.
  3. Expanding knowledge related to women’s recovery after delivery.

Featured Researchers

Brendan Carvalho, MD
CAP Profile

Pamela Flood, MD
CAP Profile

Alex Butwick, MD
CAP Profile

Pervez Sultan, MD
CAP Profile

How our research has changed practice

Research from our group has been instrumental in advancing maternal and peripartum care. Through our research, we have developed new protocols and approaches for preventing and managing postpartum hemorrhage, enhanced methods to manage mothers’ pain during labor and after cesarean delivery, improved knowledge of how drugs behave in the peripartum setting, and designed instruments to measure recovery after childbirth.

Research Recognition

Our faculty have gained recognition for their outstanding contributions to innovation and knowledge in peripartum care and obstetric anesthesiology. Our work has received funding support from the National Institute for Health, Stanford Maternal & Child Health Research Institute and industry partners. Our research has been recognized with the receipt of numerous scientific awards from several international medical societies.

At the Society of Obstetric Anesthesiology and Perinatology annual scientific meetings, the most prestigious obstetric anesthesia meeting in the world, we have won the Best Scientific Paper award on 3 occasions, and been a finalist for this award on 7 occasions. Our trainee-mentored research has been consistently recognized with an unprecedented 13 Resident/Fellow Research Presentation awards in the past 18 years. We have also received scientific meeting research awards from the American Society of Anesthesiology, Obstetric Anaesthetists’ Association of Great Britain, and the Canadian Anesthesiologists' Society.

Our work has been published in high-impact scientific journals on numerous occasions (see all publications). We have produced and contributed towards several national guidelines and consensus statements produced by the Society of Obstetric Anesthesiology and Perinatology, the American Heart Association and the World Health Organization.

Our obstetric anesthesia facility was the first in the nation to be designated as a Society for Obstetric Anesthesia and Perinatology Center of Excellence, and Brendan Carvalho was appointed as President of the Society for Obstetric Anesthesia and Perinatology between 2017 and 2018.

Recent Publications

Professor of Anesthesiology, Perioperative and Pain Medicine (Adult MSD)


  • Assessment of fatigue in postpartum women using patient-reported outcome measures: a systematic review utilising Consensus Based Standards for the Selection of Health Measurement Instruments (COSMIN) guidelines FATIGUE-BIOMEDICINE HEALTH AND BEHAVIOR Ciechanowicz, S., Pandal, P., Carvalho, B., Blake, L., Van Damme, S., Taylor, J., Sultan, P. 2022
  • A Systematic Scoping Review of Peridelivery Pain Management for Pregnant People With Opioid Use Disorder: From the Society for Obstetric Anesthesia and Perinatology and Society for Maternal Fetal Medicine. Anesthesia and analgesia Lim, G., Soens, M., Wanaselja, A., Chyan, A., Carvalho, B., Landau, R., George, R. B., Klem, M. L., Osmundson, S. S., Krans, E. E., Terplan, M., Bateman, B. T. 2022


    The prevalence of pregnant people with opioid use disorder (OUD), including those receiving medications for opioid use disorder (MOUD), is increasing. Challenges associated with pain management in people with OUD include tolerance, opioid-induced hyperalgesia, and risk for return to use. Yet, there are few evidence-based recommendations for pain management in the setting of pregnancy and the postpartum period, and many peripartum pain management studies exclude people with OUD. This scoping review summarized the available literature on peridelivery pain management in people with OUD, methodologies used, and identified specific areas of knowledge gaps. PubMed and Embase were comprehensively searched for publications in all languages on peripartum pain management among people with OUD, both treated with MOUD and untreated. Potential articles were screened by title, abstract, and full text. Data abstracted were descriptively analyzed to map available evidence and identify areas of limited or no evidence. A total of 994 publications were imported for screening on title, abstracts, and full text, yielding 84 publications identified for full review: 32 (38.1%) review articles, 14 (16.7%) retrospective studies, and 8 (9.5%) case reports. There were 5 randomized controlled trials. Most studies (64%) were published in perinatology (32; 38.1%) journals or anesthesiology (22; 26.2%) journals. Specific areas lacking trial or systematic review evidence include: (1) methods to optimize psychological and psychosocial comorbidities relevant to acute pain management around delivery; (2) alternative nonopioid and nonpharmacologic analgesia methods; (3) whether or not to use opioids for severe breakthrough pain and how best to prescribe and monitor its use after discharge; (4) monitoring for respiratory depression and sedation with coadministration of other analgesics; (5) optimal neuraxial analgesia dosing and adjuncts; and (6) benefits of abdominal wall blocks after cesarean delivery. No publications discussed naloxone coprescribing in the labor and delivery setting. We observed an increasing number of publications on peripartum pain management in pregnant people with OUD. However, existing published works are low on the pyramid of evidence (reviews, opinions, and retrospective studies), with a paucity of original research articles (<6%). Opinions are conflicting on the utility and disutility of various analgesic interventions. Studies generating high-quality evidence on this topic are needed to inform care for pregnant people with OUD. Specific research areas are identified, including utility and disutility of short-term opioid use for postpartum pain management, role of continuous wound infiltration and truncal nerve blocks, nonpharmacologic analgesia options, and the best methods to support psychosocial aspects of pain management.

    View details for DOI 10.1213/ANE.0000000000006167

    View details for PubMedID 36135926

  • Obstetric services in the UK during the COVID-19 pandemic: A national survey. Anaesthesia, critical care & pain medicine O'Carroll, J. E., Zucco, L., Warwick, E., Arbane, G., Moonesinghe, R., El-Boghdadly, K., Guo, N., Carvalho, B., Sultan, P. 2022: 101137


    The management of obstetric patients with coronavirus disease 2019 (COVID-19) due to human-to-human transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) requires unique considerations. Many aspects of labour and delivery practice required adaptation in response to the global pandemic and were supported by guidelines from the Royal College of Obstetrics and Gynaecologists. The adoption and adherence to these guidelines is unknown.Participating centres in "Quality of Recovery in Obstetric Anaesthesia study - a multicentre study" (ObsQoR) completed an electronic survey based on the provision of services and care related to COVID-19 in October 2021. The survey was designed against the Royal College of Obstetricians and Gynaecologists COVID-19 guidelines.One hundred and five of the 107 participating centres completed the survey (98% response rate representing 54% of all UK obstetric units). The median [IQR] annual number of deliveries among the included sites was 4389 [3000-5325]. Ninety-nine of the 103 (94.3%) sites had guidelines for the management of peripartum women with COVID-19. Sixty-one of 105 (58.1%) had specific guidance for venous thromboembolism (VTE) prophylaxis. Thirty-seven of 104 (35.6%) centres restricted parturient birthing plans if a positive diagnosis of COVID-19 was made. A COVID-19 vaccination referral pathway encouraging full vaccination for all pregnant women was present in 63/103 centres (61.2%).We found variability in care delivered and adherence to guidelines related to COVID-19. The clinical implications for this related to quality of peripartum care is unclear, however there remains scope to improve pathways for immunisation, birth plans and VTE prophylaxis.

    View details for DOI 10.1016/j.accpm.2022.101137

    View details for PubMedID 35914704

  • Incidence, prevalence, and timing of postpartum complications and mortality in Canada and the United States: a systematic review and meta-analysis protocol. JBI evidence synthesis Ke, J. X., Vidler, M., Dol, J., Carvalho, B., Blake, L. E., George, R. B., Bone, J., Seligman, K., Coombs, M., Chau, A. A., Saville, L., Gibbs, R. S., Sultan, P. 2022


    The goal of this systematic review is to assess the incidence, prevalence, and timing of common postpartum (up to one year after delivery) medical, surgical/procedural, and psychosocial complications and mortality.Childbirth is the most common cause for hospitalization, and cesarean delivery is the most commonly performed inpatient surgery. After delivery, mothers are at risk of short- and long-term complications that can impact their well-being. The results of this review will inform evidence-based recommendations for patient education, monitoring, and follow-up.We will include studies performed in Canada and/or the United States that report the incidence or prevalence of medical, procedural/surgical, and psychosocial complications within one year postpartum. Observational studies (analytical cross-sectional studies, retrospective and prospective cohorts), randomized or non-randomized controlled trials with a control or standard of care group, systematic reviews, and meta-analyses will be included. Studies with <100 patients, age <18 years, no reporting of duration, and focus on patients with a specific condition rather than a general postpartum population will be excluded.The search strategy was co-developed with a medical librarian and included full-text English-language articles published within the past 10 years (2011-2021) in PubMed, CINHAL, Web of Science, and Cochrane Database of Systematic Reviews. Screening, critical appraisal, and data extraction will be performed by two independent reviewers using Covidence, standardized JBI tools, and a standardized form, respectively. For each complication, the incidence or prevalence, timing of the frequency measurement, and duration of follow-up from individual studies will be determined. Meta-analysis will be performed if feasible.PROSPERO CRD42022303047.

    View details for DOI 10.11124/JBIES-21-00437

    View details for PubMedID 35975310

  • Obstetric Anesthesia Procedure-Based Workload and Facility Utilization of Society of Obstetric Anesthesia and Perinatology Centers of Excellence Designated Institutions. Anesthesia and analgesia Im, M., Riley, E. T., Hoang, D., Lim, G., Zakowski, M., Carvalho, B. 2022


    BACKGROUND: Optimal workload and staffing for obstetric anesthesia services have yet to be determined. We surveyed Society of Obstetric Anesthesia and Perinatology (SOAP) Centers of Excellence (COE) for Obstetric Anesthesia Care institutions to evaluate procedure-based obstetric anesthesia workload and facility use.METHODS: After institutional review board (IRB) exemption, an online survey instrument (REDCap) was sent by email (1 initial and 2 reminders) to all SOAP COEs. Survey data included the number of deliveries, cesarean delivery rate, neuraxial labor analgesia rate, the number of labor and operating rooms, and the number of in-house and backup obstetric anesthesia providers. Obstetric anesthesia activity was estimated using a time-based workload ratio per provider (Stanford Work Index, 1.0 = clinically working every minute of every hour on duty) during weekday, weeknight, and weekend shifts. We compared workload between academic and nonacademic centers and correlated operating and labor rooms with cesarean and vaginal delivery volume.RESULTS: Fifty-one of 53 surveys were returned (96% response rate). Data from 33 academic and 14 nonacademic US institutions were analyzed. For academic centers, median Stanford Work Index for all staff (included trainees and Certified Registered Nurse Anesthetists) was 0.20 (weekday) and 0.19 (weeknight and weekends); nonacademic centers were 0.33 (weekday, P < .001 versus academic), 0.23 (weeknight, P = .009 versus academic), and 0.23 (weekends, P = .03 versus academic practices). Attending-only Stanford Work Indices were similar between academic and nonacademic centers. Total number of rooms on the obstetric suite (operating, labor, or triage room) was strongly correlated with delivery volume (R2 = 0.55).CONCLUSIONS: The results outline staffing procedure-based workload ratios and facility utilization at SOAP COEs in the United States. These data can be used by other institutions that provide obstetric anesthesia services to guide their obstetric anesthesia staffing. The importance of considering the workload associated with different shifts and between academic and nonacademic centers is also highlighted. The results show that approximately one-third of an obstetric anesthesiologist's workload is spent on performing procedures. We did not, however, measure the other tasks anesthesiologists practice as peripartum physicians (eg, managing critically ill parturients, doing pre- and postprocedural evaluations, or performing emergent and unexpected procedures), and future studies are required to determine the time required to perform these tasks. Studies to determine the optimal staffing models to handle workload fluctuations and improve outcomes are also required.

    View details for DOI 10.1213/ANE.0000000000006112

    View details for PubMedID 35759390

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