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
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Alex Butwick, MD
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Pervez Sultan, MD
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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)


  • Impact of enhanced recovery after caesarean delivery on maternal outcomes: A systematic review and meta-analysis. Anaesthesia, critical care & pain medicine Pervez, S., Sharawi, N., Blake, L., Habib, A. S., Brookfield, K. F., Carvalho, B. 2021: 100935


    BACKGROUND: This meta-analysis explores the impact of enhanced recovery after caesarean delivery (ERAC) on maternal outcomes.METHODS: We searched 4 databases (Web of Science, Embase, PubMed and CINAHL) in October 2020 without date limiters for studies quantitatively comparing ERAC implementation to a control group. The primary outcome was length of hospital stay and secondary outcomes included time to mobilization and time to urinary catheter removal, opioid consumption, readmission rates and cost savings. Mean differences and odds ratios (MD and OR with 95% confidence intervals) were calculated. Level of evidence was assessed using GRADE.RESULTS: Twelve studies involving 17,607 patients (9,693 without ERAC and 7,914 with ERAC) were included. ERAC was associated with reduced: length of hospital stay (MD -0.51 days [-0.94, -0.09]; p = 0.018; I2 = 99%), time to first mobilization (MD -11.05hours [-18.64, -3.46]; p = 0.004; I2 = 98%), time to urinary catheter removal (MD -13.19hours [-17.59, -8.79]; p < 0.001; I2 = 97% and opioid consumption (MD -21.85mg morphine equivalents [-33.19, -10.50]; p = < 0.001; I2 = 91%), with no difference in maternal readmission rate (OR 1.23 [0.96, 1.57]; p = 0.10; I2 = 0%). Three studies reported cost savings associated with ERAC. The GRADE level of evidence was rated as low or very low quality for all study outcomes.CONCLUSION: ERAC is associated with reduction in length of stay, times to first mobilization and urinary catheter removal and opioid consumption. ERAC does not significantly affect maternal hospital readmission rates following discharge. Further studies are required to determine which ERAC interventions to implement and which outcomes best determine ERAC efficacy.

    View details for DOI 10.1016/j.accpm.2021.100935

    View details for PubMedID 34390864

  • Evidence-based guidance for use of intrathecal morphine as an alternative to diamorphine for Caesarean delivery analgesia. British journal of anaesthesia Sultan, P., Carvalho, B. 2021


    Intrathecal morphine in combination with fentanyl is an effective and safe alternative to diamorphine for Caesarean delivery analgesia. Evidence suggests minimal differences in clinical efficacy and side-effects between intrathecal morphine and diamorphine. Recommended intrathecal morphine doses for Caesarean delivery analgesia are 100-150 ug.

    View details for DOI 10.1016/j.bja.2021.06.023

    View details for PubMedID 34362559

  • Estimating Obstetric Anaesthesia Workload: Number of Deliveries Compared to Time-Based Workload TURKISH JOURNAL OF ANAESTHESIOLOGY AND REANIMATION Kowalczyk, J. J., Lipman, S. S., Carvalho, B. 2021; 49 (4): 292-297
  • Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of abdominal wall, paraspinal, and chest wall blocks. Regional anesthesia and pain medicine El-Boghdadly, K., Wolmarans, M., Stengel, A. D., Albrecht, E., Chin, K. J., Elsharkawy, H., Kopp, S., Mariano, E. R., Xu, J. L., Adhikary, S., Altiparmak, B., Barrington, M. J., Bloc, S., Blanco, R., Boretsky, K., Borglum, J., Breebaart, M., Burckett-St Laurent, D., Capdevila, X., Carvalho, B., Chuan, A., Coppens, S., Costache, I., Dam, M., Egeler, C., Fajardo, M., Gadsden, J., Gautier, P. E., Grant, S. A., Hadzic, A., Hebbard, P., Hernandez, N., Hogg, R., Holtz, M., Johnson, R. L., Karmakar, M. K., Kessler, P., Kwofie, K., Lobo, C., Ludwin, D., MacFarlane, A., McDonnell, J., McLeod, G., Merjavy, P., Moran, E., O'Donnell, B. D., Parras, T., Pawa, A., Perlas, A., Rojas Gomez, M. F., Sala-Blanch, X., Saporito, A., Sinha, S. K., Soffin, E. M., Thottungal, A., Tsui, B. C., Tulgar, S., Turbitt, L., Uppal, V., van Geffen, G. J., Volk, T., Elkassabany, N. M. 2021; 46 (7): 571-580


    BACKGROUND: There is heterogeneity in the names and anatomical descriptions of regional anesthetic techniques. This may have adverse consequences on education, research, and implementation into clinical practice. We aimed to produce standardized nomenclature for abdominal wall, paraspinal, and chest wall regional anesthetic techniques.METHODS: We conducted an international consensus study involving experts using a three-round Delphi method to produce a list of names and corresponding descriptions of anatomical targets. After long-list formulation by a Steering Committee, the first and second rounds involved anonymous electronic voting and commenting, with the third round involving a virtual round table discussion aiming to achieve consensus on items that had yet to achieve it. Novel names were presented where required for anatomical clarity and harmonization. Strong consensus was defined as ≥75% agreement and weak consensus as 50% to 74% agreement.RESULTS: Sixty expert Collaborators participated in this study. After three rounds and clarification, harmonization, and introduction of novel nomenclature, strong consensus was achieved for the names of 16 block names and weak consensus for four names. For anatomical descriptions, strong consensus was achieved for 19 blocks and weak consensus was achieved for one approach. Several areas requiring further research were identified.CONCLUSIONS: Harmonization and standardization of nomenclature may improve education, research, and ultimately patient care. We present the first international consensus on nomenclature and anatomical descriptions of blocks of the abdominal wall, chest wall, and paraspinal blocks. We recommend using the consensus results in academic and clinical practice.

    View details for DOI 10.1136/rapm-2020-102451

    View details for PubMedID 34145070

  • Integrated trajectories of the maternal metabolome, proteome, and immunome predict labor onset. Science translational medicine Stelzer, I. A., Ghaemi, M. S., Han, X., Ando, K., Hedou, J. J., Feyaerts, D., Peterson, L. S., Rumer, K. K., Tsai, E. S., Ganio, E. A., Gaudilliere, D. K., Tsai, A. S., Choisy, B., Gaigne, L. P., Verdonk, F., Jacobsen, D., Gavasso, S., Traber, G. M., Ellenberger, M., Stanley, N., Becker, M., Culos, A., Fallahzadeh, R., Wong, R. J., Darmstadt, G. L., Druzin, M. L., Winn, V. D., Gibbs, R. S., Ling, X. B., Sylvester, K., Carvalho, B., Snyder, M. P., Shaw, G. M., Stevenson, D. K., Contrepois, K., Angst, M. S., Aghaeepour, N., Gaudilliere, B. 2021; 13 (592)


    Estimating the time of delivery is of high clinical importance because pre- and postterm deviations are associated with complications for the mother and her offspring. However, current estimations are inaccurate. As pregnancy progresses toward labor, major transitions occur in fetomaternal immune, metabolic, and endocrine systems that culminate in birth. The comprehensive characterization of maternal biology that precedes labor is key to understanding these physiological transitions and identifying predictive biomarkers of delivery. Here, a longitudinal study was conducted in 63 women who went into labor spontaneously. More than 7000 plasma analytes and peripheral immune cell responses were analyzed using untargeted mass spectrometry, aptamer-based proteomic technology, and single-cell mass cytometry in serial blood samples collected during the last 100 days of pregnancy. The high-dimensional dataset was integrated into a multiomic model that predicted the time to spontaneous labor [R = 0.85, 95% confidence interval (CI) [0.79 to 0.89], P = 1.2 * 10-40, N = 53, training set; R = 0.81, 95% CI [0.61 to 0.91], P = 3.9 * 10-7, N = 10, independent test set]. Coordinated alterations in maternal metabolome, proteome, and immunome marked a molecular shift from pregnancy maintenance to prelabor biology 2 to 4 weeks before delivery. A surge in steroid hormone metabolites and interleukin-1 receptor type 4 that preceded labor coincided with a switch from immune activation to regulation of inflammatory responses. Our study lays the groundwork for developing blood-based methods for predicting the day of labor, anchored in mechanisms shared in preterm and term pregnancies.

    View details for DOI 10.1126/scitranslmed.abd9898

    View details for PubMedID 33952678

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