title: Recurrence of hypertensive disorders of pregnancy: an individual patient data metaanalysis.
abstract: OBJECTIVE
  We performed an individual participant data (IPD) metaanalysis to calculate the recurrence risk of hypertensive disorders of pregnancy (HDP) and recurrence of individual hypertensive syndromes.
  
  
  METHODS
  We performed an electronic literature search for cohort studies that reported on women experiencing HDP and who had a subsequent pregnancy. The principal investigators were contacted and informed of our study; we requested their original study data. The data were merged to form one combined database. The results will be presented as percentages with 95% confidence interval (CI) and odds ratios with 95% CI.
  
  
  RESULTS
  Of 94 eligible cohort studies, we obtained IPD of 22 studies, including a total of 99,415 women. Pooled data of 64 studies that used published data (IPD where available) showed a recurrence rate of 18.1% (n=152,213; 95% CI, 17.9-18.3%). In the 22 studies that are included in our IPD, the recurrence rate of a HDP was 20.7% (95% CI, 20.4-20.9%). Recurrence manifested as preeclampsia in 13.8% of the studies (95% CI,13.6-14.1%), gestational hypertension in 8.6% of the studies (95% CI, 8.4-8.8%) and hemolysis, elevated liver enzymes and low platelets (HELLP) syndrome in 0.2% of the studies (95% CI, 0.16-0.25%). The delivery of a small-for-gestational-age child accompanied the recurrent HDP in 3.4% of the studies (95% CI, 3.2-3.6%). Concomitant HELLP syndrome or delivery of a small-for-gestational-age child increased the risk of recurrence of HDP. Recurrence increased with decreasing gestational age at delivery in the index pregnancy. If the HDP recurred, in general it was milder, regarding maximum diastolic blood pressure, proteinuria, the use of oral antihypertensive and anticonvulsive medication, the delivery of a small-for-gestational-age child, premature delivery, and perinatal death. Normotensive women experienced chronic hypertension after pregnancy more often after experiencing recurrence (odds ratio, 3.7; 95% CI, 2.3-6.1).
  
  
  CONCLUSIONS
  Among women that experience hypertension in pregnancy, the recurrence rate in a next pregnancy is relatively low, and the course of disease is milder for most women with recurrent disease. These reassuring data should be used for shared decision-making in women who consider a new pregnancy after a pregnancy that was complicated by hypertension.
authors.affiliation: Department of Obstetrics and Gynecology, Erasmus Medical Center, Rotterdam, the Netherlands. Electronic address: miriamvanoostwaard@gmail.com.
authors.forename: Miriam F
authors.initials: MF
authors.lastname: van Oostwaard
authors.affiliation: Department of Obstetrics and Gynecology, Atrium Medical Center, Heerlen, the Netherlands.
authors.forename: Josje
authors.initials: J
authors.lastname: Langenveld
authors.affiliation: Julius Center for Health Sciences and Primary Care, Universitair Medisch Centrum, Utrecht, the Netherlands; Department of Obstetrics and Gynecology, Academic Medical Center, Amsterdam, the Netherlands; Stanford Prevention Research Center, Stanford University, Stanford, CA.
authors.forename: Ewoud
authors.initials: E
authors.lastname: Schuit
authors.affiliation: Department of Obstetrics and Gynecology, Amphia Ziekenhuis, Breda, the Netherlands.
authors.forename: Dimitri N M
authors.initials: DN
authors.lastname: Papatsonis
authors.affiliation: Department of Renal Medicine, St. George Hospital, Sydney, NSW, Australia.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Brown
authors.affiliation: Department of Obstetrics and Gynecology, St. Raphael of St. Francis Hospital, Nsambya Kampala, Uganda.
authors.forename: Romano N
authors.initials: RN
authors.lastname: Byaruhanga
authors.affiliation: Dugald Baird Center for Research on Women's Health, Aberdeen Maternity Hospital, Aberdeen, Scotland.
authors.forename: Sohinee
authors.initials: S
authors.lastname: Bhattacharya
authors.affiliation: Department of Obstetrics and Gynecology, Aberdeen Maternity Hospital, Aberdeen, Scotland.
authors.forename: Doris M
authors.initials: DM
authors.lastname: Campbell
authors.affiliation: Women's Health Academic Centre, King's College London, London, England, UK.
authors.forename: Lucy C
authors.initials: LC
authors.lastname: Chappell
authors.affiliation: Department of Obstetrics, Gynecology, and Neonatology, IRCSS Fondazione Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Chiaffarino
authors.affiliation: Department of Obstetrics and Gynecology, Ospedale San Gerardo, Università degli Studi di Milano-Bicocca, Monza, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Crippa
authors.affiliation: Department of Obstetrics and Gynecology, Universit' degli Studi di Modena e Reggio Emilia, Modena, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Facchinetti
authors.affiliation: Department of Obstetrics and Gynecology, Università Cattolica del S. Cuore, Rome, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Ferrazzani
authors.affiliation: Department of Woman, Mother, and Neonate, Buzzi Children's Hospital, Istituti Clinici di Perfezionamento, Biomedical and Clinical School of Medicine University of Milan, Milan, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Ferrazzi
authors.affiliation: Faculty of Medicine, Federal University of Mato Grosso do Sul, Campo Grande, Brazil.
authors.forename: Ernesto A
authors.initials: EA
authors.lastname: Figueiró-Filho
authors.affiliation: Department of Obstetrics and Gynecology, Jeroen Bosch Ziekenhuis, 's Hertogenbosch, the Netherlands.
authors.forename: Ingrid P M
authors.initials: IP
authors.lastname: Gaugler-Senden
authors.affiliation: Department of Gynecology and Obstetrics and Institute of Clinical Medicine, Akershus University Hospital, University of Oslo, Lørenskog, Norway.
authors.forename: Camilla
authors.initials: C
authors.lastname: Haavaldsen
authors.affiliation: Department of Obstetrics and Gynecology, Hvidovre Hospital, and Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jacob A
authors.initials: JA
authors.lastname: Lykke
authors.affiliation: Department of Epidemiology and Biostatistics, University of South Florida, Tampa, FL.
authors.forename: Alfred K
authors.initials: AK
authors.lastname: Mbah
authors.affiliation: Center for Biological and Health Sciences, Federal University of Mato Grosso do Sul, Campo Grande, Brazil.
authors.forename: Vanessa M
authors.initials: VM
authors.lastname: Oliveira
authors.affiliation: Women's Health Academic Centre, King's College London, London, England, UK.
authors.forename: Lucilla
authors.initials: L
authors.lastname: Poston
authors.affiliation: Nuffield Department of Obstetrics and Gynecology, John Radcliffe Hospital, University of Oxford, Oxford, England, UK.
authors.forename: Christopher W G
authors.initials: CW
authors.lastname: Redman
authors.affiliation: Department of Obstetrics and Gynecology, Ha'Emek Medical Center, Afula, Israel.
authors.forename: Raed
authors.initials: R
authors.lastname: Salim
authors.affiliation: Lanesborough Wing, St George's, University of London, London, England, UK.
authors.forename: Baskaran
authors.initials: B
authors.lastname: Thilaganathan
authors.affiliation: Department of Obstetrics and Gynecology, Ospedale San Gerardo, Università degli Studi di Milano-Bicocca, Monza, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Vergani
authors.affiliation: Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Obstetrics and Gynecology, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Eric A P
authors.initials: EA
authors.lastname: Steegers
authors.affiliation: School of Pediatrics and Reproductive Health, Robinson Institute, University of Adelaide, SA, Australia.
authors.forename: Ben Willem J
authors.initials: BW
authors.lastname: Mol
authors.affiliation: Department of Obstetrics and Gynecology, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Wessel
authors.initials: W
authors.lastname: Ganzevoort
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000627:therapeutic use; D002908:Chronic Disease; D015331:Cohort Studies; D005260:Female; D017359:HELLP Syndrome / Q000188:drug therapy / Q000453:epidemiology*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D046110:Hypertension, Pregnancy-Induced / Q000188:drug therapy / Q000453:epidemiology; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D049590:Postpartum Period; D011225:Pre-Eclampsia / Q000188:drug therapy / Q000453:epidemiology*; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology; D012008:Recurrence; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D000927:Anticonvulsants; D000959:Antihypertensive Agents
keywords: HELLP syndrome; IPD; gestational hypertension; preeclampsia; pregnancy; recurrence