• von Dadelszen, Peter

    Investigator, BC Children's Hospital

    Consultant in Maternal Fetal Medicine, BC Women's Hospital & Health Centre
    Affiliate Professor, Division of Maternal Fetal Medicine, Department of Obstetrics & Gynaecology, University of British Columbia 

    Degrees / Designations
    Primary Area of Research
    Healthy Starts
    Secondary Area(s) of Research
    Lab Phone
    Loren Spagnuolo
    Assistant Phone
    Mailing Address

    Clinical Support Building
    Room V3-339
    948 West 28th Ave.
    Vancouver, BC V6H 3N1

    Affiliate Websites
    Research Areas
    • Pre-eclampsia / Hypertension in pregnancy / IUGR
    • Th2 pregnancy immunology / Infection & atherosis
    • Clinical epidemiology / Health services research
    • Flow cytometry / Cell & molecular biology / Translational research

    Pre-eclampsia ('toxaemia' of pregnancy; high blood pressure and the loss of protein in the urine) is the most common cause of maternal death in North America, and the second leading cause of maternal death globally. It also causes an excess burden of illness and death for fetuses, especially when pregnancies are affected remote from term. The process of pre-eclampsia seems to involve inappropriate activation of the immune system, causing inflammation and organ damage.

    We are investigating what aspect of the inflammatory response is specific to pre-eclampsia, how to quantify the multi-organ consequences of that inflammatory response, and how to modify the response to safely prolong pregnancies affected remote from term and to accelerate the recovery from the inflammation postnatally. In low and middle income countries, we are investigating community-level interventions to improve monitoring, prevention and treatment of women with pre-eclampsia to reduce the burden of life-ending, life-altering, and life-threatening events that complicate the pregnancies of these women.

    In addition, we are studying the relationship between a woman’s immune cells in the womb (uterus) and the successful formation of the afterbirth (placenta).

    Current Projects

    PRE-EMPT (PRE-eclampsia-Eclampsia Monitoring, Prevention & Treatment)
    We have been funded by the Bill & Melinda Gates Foundation (BMGF) to lead an international initiative designed to reduce the burden of pre-eclampsia through community-level prevention, case identification and monitoring, and treatment. PRE-EMPT has five component studies.

    The first is a clinical trial to determine if increased calcium intake prior to and during the first half of pregnancy reduces the risk of developing pre-eclampsia.

    Secondly, we will modify the PIERS model (see below) to develop and validate the miniPIERS model, which is symptom and signed-based, for use in rural and remote communities and low and middle income countries. The miniPIERS project has the support of the BMGF, WHO, USAID and the CIHR, and is taking place in Brazil, China, Fiji, Pakistan, South Africa, and Uganda.

    Third, we will incorporate the miniPIERS model into the CLIP (Community Level Intervention for Pre-eclampsia) package of care. This package of care will empower specifically trained community health workers to better identify women with pre-eclampsia, accelerate their transfer to effective care, and intervene with proven therapies to reduce the risks of seizures and stroke.

    Fourth, we will convene an international data and biological sample collaboration – the Pre-eclampsia CoLaboratory – that will facilitate new knowledge generation and rapidly increase our ability to intervene to avoid the adverse outcomes of pre-eclampsia.

    Fifth, we will support the WHO as it updates its international guidelines to improve the care of women with pre-eclampsia and other forms of pregnancy hypertension.

    PIERS (Pre-eclampsia Integrated Estimate of RiSk)
    We are investigating a range of potential predictors of adverse maternal outcomes in women admitted to hospital with pre-eclampsia. With CIHR support and in collaboration with the World Health Organization (WHO), fullPIERS is for use in well-resourced settings and was developed and validated in tertiary units in Canada, New Zealand, Australia, and the UK in women with pre-eclampsia. fullPIERS now requires external validation, which is underway. The second version, of the PIERS model, miniPIERS, is discussed above (PRE-EMPT).

    Recently, in collaboration with Mark Ansermino (co-PI) and Guy Dumont, we received a Saving Lives at Birth seed grant for the project, PIERS on the Move, whereby we will develop a cell phone-based pulse oximeter, sphygmomanometer and decision aid for use by community health workers in low and middle income countries. As pulse oximetry is a powerful component of fullPIERS, we anticipate that the phone oximeter will transform miniPIERS into a model that approximates fullPIERS in diagnostic and stratification performance.

    We are investigating the interaction between first trimester extravillous trophoblast (EVT) and decidual natural killer cells (dNK) using a novel ex vivo model of placentation. In this model we co-culture either maternal immune cells, dNK, or their conditioned medium, with either villous tip explants, isolated EVT, or an EVT-derived cell line, to examine the key interactions that appear to modulate the success or relative/complete failure of EVT invasion. We have determined that dNK limit EVT migration while appearing to promote EVT neovasculogenesis. These interactions underlie the quality of placentation and the risk of subsequent placental complications in pregnancy.

    Selected Publications

    • Thangaratinam S, Allotey J, Marlin N, Dodds J, Cheong-See F, von Dadelszen P, Ganzevoort W, Akkermans J, Kerry S, Mol BW, Moons KG, Riley RD, Khan KS, PREP Collaborative Network. "Prediction of complications in early-onset pre-eclampsia (PREP): Development and external multinational validation of prognostic models." BMC Med. 2017 Apr 04. PMID: 28356148
    • Sharma S, Adetoro OO, Vidler M, Drebit S, Payne BA, Akeju DO, Adepoju A, Jaiyesimi E, Sotunsa J, Bhutta ZA, Magee LA, von Dadelszen P, Dada O."A process evaluation plan for assessing a complex community-based maternal health intervention in Ogun State, Nigeria."  BMC Health Serv Res. 2017 Apr 4. PMID: 28351355
    • Mateus J, Newman R, Sibai BM, Li Q, Barton JR, Combs CA, Guzman E, Boggess KA, Gyamfi C, von Dadelszen P, Woelkers D. "Massive Urinary Protein Excretion Associated with Greater Neonatal Risk in Preeclampsia." AJP Rep. 2017 Apr 04. PMID: 28348923
    • von Dadelszen P, Payne B, Menzies JM, Li J, Ansermino JM, Broughton Pipkin F, Côté AM, Douglas MJ, Gruslin A, Hutcheon JA, Joseph KS, Kyle PM, Lee T, Loughna P, Merialdi M, Millman AL, Moore MP, Moutquin JM, Ouellet AB, Smith GN, Walker JJ, Walley KR, Walters BN, Widmer M, Lee SK, Russell JR, Magee LA, for the PIERS Study Group. Predicting adverse maternal outcomes in pre-eclampsia: the fullPIERS (Pre-eclampsia Integrated Estimate of RiSk) model – development and validation. Lancet 2011;377:219-227. PMID: 21185591
    • von Dadelszen P, Sawchuck D, McMaster R, Douglas MJ, Joseph KS, Lee SK, Mitton C, Saunders S, Liston RM, Magee LA, for the TESS (Translating Evidence-based Surveillance and treatment Strategies) Group. The active implementation of pregnancy hypertension guidelines in British Columbia. Obstet Gynecol 2010;116:659-666. PMID: 20733449
    • Steegers EAP, von Dadelszen P, Duvekot JJ, Pijnenborg R. Seminar: pre-eclampsia. Lancet 2010;376:631-6442010 (Epub ahead of print). PMID: 20598363
    • Hu Y, Eastabrook G, Tan R, MacCalman CD, Dutz JP, von Dadelszen P. Decidual NK cell-derived conditioned medium enhances capillary tube and network organization in an extravillous cytotrophoblast cell line through up-regulation of ICAM-1 expression. Placenta 2010;31:213-221. PMID: 20080299
    • Xie F, Hu Y, Turvey SE, Magee LA, Brunham RC, Choi KC, Krajden M, Leung PCK, Money DM, Patrick DM, Thomas E, von Dadelszen P. Toll-like receptors 2 and 4 and the cryopyrin inflammasome in normal pregnancy and pre-eclampsia. BJOG 2010;117:99-108. PMID: 20002372
    • Côté AM, von Dadelszen P, Brown MA, Firoz T, Lam EM, Liston RM, Magee LA. The urinary spot protein/creatinine ratio is a reasonable diagnostic test for proteinuria in hypertensive pregnancy: systematic review. BMJ 2008;336:1003-1006. PMID: 18403498
    • Menzies J, Magee LA, MacNab YC, Li J, Yin R, Stuart H, Baraty B, Lam E, Hamilton T, Lee SK, von Dadelszen P for the Pre-eclampsia Integrated Estimate of RiSk (PIERS) Study Group. Instituting surveillance guidelines and adverse outcomes in preeclampsia. Obstet Gynecol 2007;110:121-127. PMID: 17601906
    • Hu Y, Dutz R, Tan R, MacCalman C, Yong P, von Dadelszen P. Decidual natural killer cells alter in vitro first trimester extravillous cytotrophoblast migration; a role for interferon-gamma. J Immunol 2006:177 8522-8530. PMID: 17142750
    • Magee LA, Cham C, Waterman EJ, Ohlsson A, von Dadelszen P. Hydralazine for treatment of severe hypertension in pregnancy: meta-analysis. BMJ 2003;327:955-960. PMID: 14576246
    • von Dadelszen P, Ornstein MP, Bull SB, Logan AG, Koren G, Magee LA. Fall in mean arterial pressure and fetal growth restriction in pregnancy hypertension: a meta-analysis. Lancet 2000;355:87-92 (PMID: 10675164). PMID: 10675164
    • Magee LA, Ornstein MP, von Dadelszen P. Fortnightly review. The management of hypertension in pregnancy. BMJ 1999; 318:1332-1336. PMID: 10323823
    • Ukah UV, Adu PA, De Silva DA, von Dadelszen P. The Impact of a History of Adverse Childhood Experiences on Breastfeeding Initiation and Exclusivity: Findings from a National Population Health SurveyBreastfeed Med. 2016 Dec;11:544-550. PubMed PMID: 27726425.
    • Ukah UV, Mbofana F, Rocha BM, Loquiha O, Mudenyanga C, Usta M, Urso M, Drebit S, Magee LA, von Dadelszen P. Diagnostic Performance of Placental Growth Factor in Women With Suspected Preeclampsia Attending Antenatal Facilities in Maputo, Mozambique. Hypertension. 2017 Jan 1:HYPERTENSIONAHA-116 
    • Thornton C, Tooher J, Ogle R, von Dadelszen P, Makris A, Hennessy A. Benchmarking the Hypertensive Disorders of Pregnancy. Pregnancy Hypertens. 2016 Oct. PMID:27939468 
    • Robertson JE, Lisonkova S, Lee T, De Silva DA, von Dadelszen P, Synnes AR, Joseph KS, Liston RM, Magee LA. Fetal, Infant and Maternal Outcomes among Women with Prolapsed Membranes Admitted before 29 Weeks GestationPloS One.2016 Dec 21;11(12):e0168285.
    • Makanga PT, Schuurman N, Sacoor C, Boene HE, Vilanculo F, Vidler M, Magee L, Dadelszen P, Sevene E, Munguambe K, Firoz T. Seasonal variation in geographical access to maternal health services in regions of southern Mozambique. International Journal of Health Geographics. 2017 Jan 13;16(1):1.  
    • Magee LA, Pels A, Helewa M, Rey E, von Dadelszen P. Diagnostic, évaluation et prise en charge des troubles hypertensifs de la grossesse : Résumé directif. J Obstet Gynaecol Can. 2016 Dec PMID: 28063555
    • Duffy JM, van 't Hooft J, Gale C, Brown M, Grobman W, Fitzpatrick R, Karumanchi SA, Lucas N, Magee L, Mol B, Stark M, Thangaratinam S, Wilson M, von Dadelszen P, Williamson P, Khan KS, Ziebland S, McManus RJ; International Collaboration to Harmonise Outcomes for Pre-eclampsia (iHOPE). A protocol for developing, disseminating, and implementing a core outcome set for pre-eclampsia. Pregnancy Hypertens. 2016 Oct. PMID: 27939467



    CIHR Operating Grant - Project: "The Canadian STRIDER Trial: sildenafil for dismal prognosis IUGR" (2014-2019)

    CIHR Operating Grant - Project "The fullPIERS risk prediction model for women with pre-eclampsia: external validation and added value of a novel biomarker" (2014-2016)

    Honours & Awards

    Chesley Award, International Society for the Study of Hypertension in Pregnancy (ISSHP) - October 2014

    2014 APOG Excellence in Research Award, Association of Academic Professionals in Obstetrics and Gynecology of Canada - September 2014

    Grand Challenges Canada Direct Entry Program

    CIHR Knowledge Translation Award 

    Safe Motherhood and Newborn Health Committee

    JN de Villiers Memorial Lecture
    University of Stellenbosch, South Africa

    Physicians’ Board
    UN/WHO/UN University Women’s Health and Education Centre, United States

    Medical Advisory Board
    Preeclampsia Foundation, United States

    Senior Scholar Research Award
    Michael Smith Foundation for Health Research, Canada

    North American Society for the Study of Hypertension in Pregnancy, Canada

    Hypertension in Pregnancy

    New Investigator Research Award
    CIHR, Canada
    Research Group Members
    • Yuxiang Hu, MD, Laboratory Manager
    • Diane Sawchuck, RN, PhD, PRE-EMPT Project Manager & Perinatal Knowledge Broker
    • Jing (Larry) Li, MCS, Sr. Database Manager
    • Beth Payne, BSc, Research Coordinator, PIERS, CLIP, & CPN Projects & PhD Candidate
    • Theresa Yong, Research Coordinator, CPN Project
    • Frank Qu, BCSc, Database Manager, Research Assistant
    • Tang Lee, MSc, Statistician, Research Assistant
    • Jennifer Lee, RN, Research Coordinator, MIREC Project
    • Tanya Willar, Research Assistant
    • Raj Padda, MD, Research Assistant
    • Gabrielle Inglis, BSc, Research Assistant
    • Genevieve Eastabrook, MD, FRCSC, PhD Candidate & MFM Fellow
    • Samantha Benton, PhD Candidate