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

Alex Butwick, MD
CAP Profile

Pervez Sultan, MD
CAP Profile

Brian Bateman,MD,MSc
CAP Profile

Jessica Ansari, MD, MS
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) and, by courtesy, of Obstetrics and Gynecology (Maternal Fetal Medicine)


  • Physical activity among pregnant inpatients and outpatients and associations with anxiety. European journal of obstetrics, gynecology, and reproductive biology Panelli, D. M., Miller, H. E., Simpson, S. L., Hurtado, J., Shu, C. H., Boncompagni, A. C., Chueh, J., Carvalho, B., Sultan, P., Aghaeepour, N., Druzin, M. L. 2024; 297: 8-14


    Physical activity is linked to lower anxiety, but little is known about the association during pregnancy. This is especially important for antepartum inpatients, who are known to have increased anxiety yet may not be able to achieve target levels of physical activity during hospitalization. We compared physical activity metrics between pregnant inpatients and outpatients and explored correlations with anxiety.This was a prospective cohort between 2021 and 2022 of pregnant people aged 18-55 years carrying singleton gestations ≥ 16 weeks. Three exposure groups were matched for gestational age: 1) outpatients from general obstetric clinics; 2) outpatients from high-risk Maternal-Fetal Medicine obstetric clinics; and 3) antepartum inpatients. Participants wore Actigraph GT9X Link accelerometer watches for up to 7 days to measure physical activity. The primary outcome was mean daily step count. Secondary outcomes were metabolic equivalent tasks (METs), hourly kilocalories (kcals), moderate to vigorous physical activity (MVPA) bursts, and anxiety (State-Trait Anxiety Inventory [STAI]). Step counts were compared using multivariable generalized estimating equations adjusting for maternal age, body-mass index, and insurance type as a socioeconomic construct, accounting for within-group clustering by gestational age. Spearman correlations were used to correlate anxiety scores with step counts.58 participants were analyzed. Compared to outpatients, inpatients had significantly lower mean daily steps (primary outcome, adjusted beta -2185, 95 % confidence interval [CI] -3146, -1224, p < 0.01), METs (adjusted beta -0.18, 95 % CI -0.23, -0.13, p < 0.01), MVPAs (adjusted beta -38.2, 95 % CI -52.3, -24.1, p < 0.01), and kcals (adjusted beta -222.9, 95 % CI -438.0, -7.8, p = 0.04). Over the course of the week, steps progressively decreased for inpatients (p-interaction 0.01) but not for either of the outpatient groups. Among the entire cohort, lower step counts correlated with higher anxiety scores (r = 0.30, p = 0.02).We present antenatal population norms and variance for step counts, metabolic equivalent tasks, moderate to vigorous physical activity bursts, and kcals, as well as correlations with anxiety. Antepartum inpatients had significantly lower physical activity than outpatients, and lower step counts correlated with higher anxiety levels. These results highlight the need for physical activity interventions, particularly for hospitalized pregnant people.

    View details for DOI 10.1016/j.ejogrb.2024.03.033

    View details for PubMedID 38554481

  • Continuous wound infusion catheter as part of a multimodal analgesia regimen for post-Caesarean delivery pain: a quality improvement impact study. BJA open Fowler, C., Stockert, E., Hoang, D., Guo, N., Riley, E., Sultan, P., Carvalho, B. 2024; 9: 100242


    The role of continuous wound infusion catheters as part of a multimodal analgesia strategy after Caesarean delivery is unclear. We introduced continuous wound infusion catheters to our multimodal analgesia regimen to evaluate the impact on analgesic outcomes after Caesarean delivery.After institutional review board (IRB) approval, a 4-month practice change was instituted as a quality improvement initiative. In addition to multimodal analgesia, continuous wound infusion catheters for up to 3 days were offered on alternate weeks for all women undergoing Caesarean deliveries. The primary outcome was postoperative in-hospital opioid consumption. Secondary outcomes were static and dynamic pain scores at 24 and 72 h, time until first analgesic request, opioid-related side-effects, length of stay, satisfaction (0-100%), and continuous wound infusion catheter-related complications.All women scheduled for Caesarean delivery (n=139) in the 4-month period were included in the analysis, with 70 women receiving continuous wound infusion catheters, and 69 in the control group. Opioid consumption (continuous wound infusion catheter group 11.3 [7.5-61.9] mg morphine equivalents vs control group 30.0 [11.3-48.8] mg morphine equivalents), pain scores (except 24 h resting pain scores which were higher in the control group 2 [1-3] vs 1.5 [0-3] in the continous wound infusion catheters group; P=0.05), side-effects, length of stay, and complications were similar between groups. Satisfaction scores at 24 h were higher with continuous wound infusion catheters (100% [91-100%] vs 90% [86-100%]; P=0.003) with no differences at 72 h. One patient demonstrated symptoms of systemic local anaesthetic toxicity which resolved without significant harm.The addition of continuous wound infusion catheters to a multimodal analgesia regimen for post-Caesarean delivery pain management demonstrated minimal clinically significant analgesic benefits. Future studies are needed to explore the use of continuous wound infusion catheters in populations that may benefit most from this intervention.

    View details for DOI 10.1016/j.bjao.2023.100242

    View details for PubMedID 38179106

    View details for PubMedCentralID PMC10761342

  • Ethnicity, socio-economic deprivation and postpartum outcomes following caesarean delivery: a multicentre cohort study. Anaesthesia O'Carroll, J. E., Zucco, L., Warwick, E., Radcliffe, G., Moonesinghe, S. R., El-Boghdadly, K., Guo, N., Carvalho, B., Sultan, P. 2024


    Disparities relating to postpartum recovery outcomes in different socio-economic and racial ethnic groups are underexplored. We conducted a planned analysis of a large prospective caesarean delivery cohort to explore the relationship between ethnicity, socio-economic status and postpartum recovery. Eligible patients were enrolled and baseline demographic, obstetric and medical history data were collected 18 h and 30 h following delivery. Patients completed postpartum quality of life and recovery measures in person on day 1 (EuroQoL EQ-5D-5L, including global health visual analogue scale; Obstetric Quality of Recovery-10 item score; and pain scores) and by telephone between day 28 and day 32 postpartum (EQ-5D-5L and pain scores). Socio-economic group was determined according to the Index of Multiple Deprivation quintile of each patient's usual place of residence. Data from 1000 patients who underwent caesarean delivery were included. There were more patients of Asian, Black and mixed ethnicity in the more deprived quintiles. Patients of White ethnicities had shorter postpartum duration of hospital stay compared with patients of Asian and Black ethnicities (35 (28-56 [18-513]) h vs. 44 (31-71 [19-465]) h vs. 49 (33-75 [23-189]) h, respectively. In adjusted models at day 30, patients of Asian ethnicity had a significantly greater risk of moderate to severe pain (numerical rating scale ≥ 4) at rest and on movement (odds ratio (95%CI) 2.42 (1.24-4.74) and 2.32 (1.40-3.87)), respectively). There were no differences in readmission rates or incidence of complications between groups. Patients from White ethnic backgrounds experience shorter postpartum duration of stay compared with patients from Asian and Black ethnic groups. Ethnic background impacts pain scores and recovery at day 1 postpartum and following hospital discharge, even after adjusting for socio-economic group. Further work is required to understand the underlying factors driving differences in pain and recovery and to develop strategies to reduce disparities in obstetric patients.

    View details for DOI 10.1111/anae.16241

    View details for PubMedID 38359531

  • A Cost and Waste-Savings Comparison Between Single-Use and Reusable Pulse Oximetry Sensors Across US Operating Rooms. Anesthesia and analgesia Stockert, E. W., Carvalho, B., Sun, E. C. 2024


    BACKGROUND: Operating room (OR) expenditures and waste generation are a priority, with several professional societies recommending the use of reprocessed or reusable equipment where feasible. The aim of this analysis was to compare single-use pulse oximetry sensor stickers ("single-use stickers") versus reusable pulse oximetry sensor clips ("reusable clips") in terms of annual cost savings and waste generation across all ORs nationally.METHODS: This study did not involve patient data or research on human subjects. As such, it did not meet the requirements for institutional review board approval. An economic model was used to compare the relative costs and waste generation from using single-use stickers versus reusable clips. This model took into account: (1) the relative prices of single-use stickers and reusable clips, (2) the number of surgeries and ORs nationwide, (3) the workload burden of cleaning the reusable clips, and (4) the costs of capital for single-use stickers and reusable clips. In addition, we also estimated differences in waste production based on the raw weight plus unit packaging of single-use stickers and reusable clips that would be disposed of over the course of the year, without any recycling interventions. Estimated savings were rounded to the nearest

  • The Accuracy of ChatGPT-Generated Responses in Answering Commonly Asked Patient Questions About Labor Epidurals: A Survey-Based Study. Anesthesia and analgesia Mootz, A. A., Carvalho, B., Sultan, P., Nguyen, T. P., Reale, S. C. 2024

    View details for DOI 10.1213/ANE.0000000000006801

    View details for PubMedID 38180897

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