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Featured researches published by Jon Barrett.


BMJ | 2016

Prospective risk of stillbirth and neonatal complications in twin pregnancies: systematic review and meta-analysis

Fiona Cheong-See; Ewoud Schuit; David Arroyo-Manzano; Asma Khalil; Jon Barrett; K.S. Joseph; Elizabeth Asztalos; K. E. A. Hack; Liesbeth Lewi; Arianne Lim; Sophie Liem; Jane E. Norman; John C. Morrison; C. Andrew Combs; Thomas J. Garite; Kimberly Maurel; Vicente Serra; Alfredo Perales; Line Rode; Katharina Worda; Anwar H. Nassar; M. Aboulghar; Dwight J. Rouse; Elizabeth Thom; Fionnuala Breathnach; Soichiro Nakayama; Francesca Maria Russo; Julian N. Robinson; Jodie M Dodd; Roger B. Newman

Objective To determine the risks of stillbirth and neonatal complications by gestational age in uncomplicated monochorionic and dichorionic twin pregnancies. Design Systematic review and meta-analysis. Data sources Medline, Embase, and Cochrane databases (until December 2015). Review methods Databases were searched without language restrictions for studies of women with uncomplicated twin pregnancies that reported rates of stillbirth and neonatal outcomes at various gestational ages. Pregnancies with unclear chorionicity, monoamnionicity, and twin to twin transfusion syndrome were excluded. Meta-analyses of observational studies and cohorts nested within randomised studies were undertaken. Prospective risk of stillbirth was computed for each study at a given week of gestation and compared with the risk of neonatal death among deliveries in the same week. Gestational age specific differences in risk were estimated for stillbirths and neonatal deaths in monochorionic and dichorionic twin pregnancies after 34 weeks’ gestation. Results 32 studies (29 685 dichorionic, 5486 monochorionic pregnancies) were included. In dichorionic twin pregnancies beyond 34 weeks (15 studies, 17 830 pregnancies), the prospective weekly risk of stillbirths from expectant management and the risk of neonatal death from delivery were balanced at 37 weeks’ gestation (risk difference 1.2/1000, 95% confidence interval −1.3 to 3.6; I2=0%). Delay in delivery by a week (to 38 weeks) led to an additional 8.8 perinatal deaths per 1000 pregnancies (95% confidence interval 3.6 to 14.0/1000; I2=0%) compared with the previous week. In monochorionic pregnancies beyond 34 weeks (13 studies, 2149 pregnancies), there was a trend towards an increase in stillbirths compared with neonatal deaths after 36 weeks, with an additional 2.5 per 1000 perinatal deaths, which was not significant (−12.4 to 17.4/1000; I2=0%). The rates of neonatal morbidity showed a consistent reduction with increasing gestational age in monochorionic and dichorionic pregnancies, and admission to the neonatal intensive care unit was the commonest neonatal complication. The actual risk of stillbirth near term might be higher than reported estimates because of the policy of planned delivery in twin pregnancies. Conclusions To minimise perinatal deaths, in uncomplicated dichorionic twin pregnancies delivery should be considered at 37 weeks’ gestation; in monochorionic pregnancies delivery should be considered at 36 weeks. Systematic review registration PROSPERO CRD42014007538.


BMC Pregnancy and Childbirth | 2017

The effect of induction method in twin pregnancies: a secondary analysis for the twin birth study

Elad Mei-Dan; Elizabeth Asztalos; Andrew R. Willan; Jon Barrett

BackgroundThis secondary analysis for the Twin Birth Study, an international, multicenter trial, aimed to compare the cesarean section rates and safety between methods of induction of labor in twin pregnancies.MethodsWomen with twin pregnancies where the first twin was in a cephalic presentation and who presented for labor induction, were non-randomly assigned to receive prostaglandin or amniotomy and/or oxytocin. Main outcome measures were the rates of unplanned cesarean section and neonatal and maternal mortality or serious morbidity.Results153 (41.5%) were induced by prostaglandin (prostaglandin group) and 215 (58.5%) were induced by amniotomy and/or oxytocin alone (no prostaglandin group). Induction using prostaglandin was more common in countries with a low perinatal mortality rate <10/1000 (45.7 versus 32.5%, p = 0.02). Cesarean section rates were similar in the two groups: 62/153 (40.5%) in the prostaglandin group and 87/215 (40.5%) in the no prostaglandin group (odds ratio 1, 95% CI 0.65-1.5). Nulliparity, late maternal age, non-cephalic presentation of twin B and high country’s perinatal mortality rate were found to be independently associated with the induction to end with an unplanned cesarean section. There were no significant differences between groups with respect to maternal or neonatal adverse outcomes.ConclusionsThe need for cervical ripening by prostaglandin had no effect on the incidence of cesarean delivery or an abnormal outcome. There is a significant risk of unplanned cesarean section independent of chosen induction method.Trial registrationThis trial was registered at the International Standard Randomized Controlled Trial Register (identifier ISRCTN74420086; December 9, 2003) and retrospectively registered at the www.clinicaltrials.gov (identifier NCT 00187369; September 12, 2005).


Obstetric Anesthesia Digest | 1999

Effect of Epidural vs Parenteral Opioid Analgesia on the Progress of Labor A Meta-Analysis

S. H. Halpem; Barbara L. Leighton; Arne Ohlsson; Jon Barrett; A. Rice

Context.—Epidural labor analgesia, if selected by the patient, is associated with high cesarean delivery rates. Results of randomized trials comparing rates of cesarean delivery using epidural anesthesia vs parenteral opioids are inconsistent. Objective.—To review the effects of epidural vs parenteral opioid analgesia on cesarean delivery rates. Data Sources.—Studies were identified by searching MEDLINE from January 1966 through January 1998, the Cochrane Database of Perinatal Trials, and relevant nonindexed journals and abstracts. Study Selection.—We included all studies that randomized patients to epidural vs parenteral opioid labor analgesia. Data Extraction.—Two authors independently extracted data from 10 trials enrolling 2369 patients. Odds ratios (ORs) for categorical data, weighted mean differences (WMDs) for continuous data, and 95% confidence intervals (CIs) were calculated using a random-effects model. Data Synthesis.—The risk of cesarean delivery did not differ between patients receiving epidural (8.2%) vs parenteral opioid (5.6%) analgesia (OR, 1.5; 95% CI, 0.81-2.76). Epidural patients had longer first (WMD, 42 minutes; 95% CI, 17-68 minutes) and second (WMD, 14 minutes; 95% CI, 5-23 minutes) labor stages. While epidural patients were more likely to have instrumented delivery (OR, 2.19; 95% CI, 1.32-7.78), they were no more likely to have instrumented delivery for dystocia (OR, 0.68; 95% CI, 0.31-1.49). After epidural analgesia, neonates were less likely to have low 5-minute Apgar scores (OR, 0.38; 95% CI, 0.18-0.81) or to need naloxone (OR, 0.24; 95% CI, 0.07-0.77). Women receiving epidural analgesia had lower pain scores during the first (WMD, −40 mm on a 100-mm scale; 95% CI, −42 to −38 mm) and second (WMD, −29 mm; 95% CI, −38 to −21 mm) stages of labor. The odds of dissatisfaction were lower with epidural analgesia (OR, 0.25; 95% CI, 0.20-0.32). Conclusions.—Epidural labor analgesia is not associated with increased rates of instrumented vaginal delivery for dystocia or cesarean delivery. Patients receiving epidural analgesia have longer labors. Patient satisfaction and neonatal outcome are better after epidural than parenteral opioid analgesia. JAMA. 1998;280:2105-2110


Diabetes Care | 2018

Pumps or Multiple Daily Injections in Pregnancy Involving Type 1 Diabetes: A Prespecified Analysis of the CONCEPTT Randomized Trial

Denice S. Feig; Rosa Corcoy; Lois E. Donovan; Kellie Murphy; Jon Barrett; Johanna Sanchez; Tim Wysocki; Katrina J. Ruedy; Craig Kollman; George Tomlinson; Helen R. Murphy

OBJECTIVE To compare glycemic control, quality of life, and pregnancy outcomes of women using insulin pumps and multiple daily injection therapy (MDI) during the Continuous Glucose Monitoring in Women With Type 1 Diabetes in Pregnancy Trial (CONCEPTT). RESEARCH DESIGN AND METHODS This was a prespecified analysis of CONCEPTT involving 248 pregnant women from 31 centers. Randomization was stratified for pump versus MDI and HbA1c. The primary outcome was change in HbA1c from randomization to 34 weeks’ gestation. Key secondary outcomes were continuous glucose monitoring (CGM) measures, maternal-infant health, and patient-reported outcomes. RESULTS At baseline, pump users were more often in stable relationships (P = 0.003), more likely to take preconception vitamins (P = 0.03), and less likely to smoke (P = 0.02). Pump and MDI users had comparable first-trimester glycemia: HbA1c 6.84 ± 0.71 vs. 6.95 ± 0.58% (51 ± 7.8 vs. 52 ± 6.3 mmol/mol) (P = 0.31) and CGM time in target (51 ± 14 vs. 50 ± 13%) (P = 0.40). At 34 weeks, MDI users had a greater decrease in HbA1c (−0.55 ± 0.59 vs. −0.32 ± 0.65%, P = 0.001). At 24 and 34 weeks, MDI users were more likely to achieve target HbA1c (P = 0.009 and P = 0.001, respectively). Pump users had more hypertensive disorders (P = 0.011), mainly driven by increased gestational hypertension (14.4 vs. 5.2%; P = 0.025), and more neonatal hypoglycemia (31.8 vs. 19.1%, P = 0.05) and neonatal intensive care unit (NICU) admissions >24 h (44.5 vs. 29.6%; P = 0.02). Pump users had a larger reduction in hypoglycemia-related anxiety (P = 0.05) but greater decline in health/well-being (P = 0.02). CONCLUSIONS In CONCEPTT, MDI users were more likely to have better glycemic outcomes and less likely to have gestational hypertension, neonatal hypoglycemia, and NICU admissions than pump users. These data suggest that implementation of insulin pump therapy is potentially suboptimal during pregnancy.


Archive | 1998

Effect of Epidural vs Parenteral Opioid Analgesia on the Progress of Labor

Stephen H. Halpern; Barbara L. Leighton; Arne Ohlsson; Jon Barrett; Amy Rice


American Journal of Obstetrics and Gynecology | 2016

Twin Birth Study: 2-year neurodevelopmental follow-up of the randomized trial of planned cesarean or planned vaginal delivery for twin pregnancy

Elizabeth Asztalos; Mary E. Hannah; Eileen K. Hutton; Andrew R. Willan; Alexander C. Allen; B. Anthony Armson; Amiram Gafni; K.S. Joseph; Arne Ohlsson; Susan Ross; Johanna Sanchez; Kathryn Mangoff; Jon Barrett


Archive | 2000

Management of Twin Pregnancies (Part 1)

Jon Barrett; Alan D. Bocking; Nan Okun; Gareth Seaward; J. J. Wilkinson; Tony Armson; André Bastide; Robert Goldenberg; Mary E. Hannah; Steve Lye; Renato Natale; David Rouselle; Rory Windrim; Kathy Fong; Louis G. Keith; Ian Lange; David Rosman; David Young; Greg Davies; Michael Helewa; Ken Milne; Knox Ritchie; Karen Ash; Nicholas M. Fisk; André Gagnon; Rob Gratton; Greg Ryan; John R. Smith; Elizabeth Bryan; Cathy Cameron


Obstetric Anesthesia Digest | 2017

Prospective Risk of Stillbirth and Neonatal Complications in Twin Pregnancies: Systematic Review and Meta-analysis

Fiona Cheong-See; Ewoud Schuit; David Arroyo-Manzano; Asma Khalil; Jon Barrett; K.S. Joseph; Elizabeth Asztalos; K. E. A. Hack; Liesbeth Lewi; Arianne Lim; Sophie Liem; Jane E. Norman; John P. Morrison; C.A. Combs; Thomas J. Garite; Kimberly Maurel; Vicente Serra; Alfredo Perales; Line Rode; Katharina Worda; Anwar H. Nassar; M. Aboulghar; Dwight J. Rouse; Elizabeth Thom; Fionnuala Breathnach; Soichiro Nakayama; Francesca Maria Russo; Julian N. Robinson; Jodie M Dodd; Roger B. Newman


/data/revues/00029378/v208i1sS/S0002937812015517/ | 2012

303: Labour induction versus elective cesarean section in nulliparous women with unfavourable cervix at term: maternal and perinatal consequences

B. Anthony Armson; Ks Joseph; Elizabeth Asztalos; Colleen O'Connell; Jon Barrett


/data/revues/00029378/v208i1sS/S0002937812012641/ | 2012

7: The Twin Birth Study: a multicenter RCT of planned cesarean section (CS) and planned vaginal birth (VB) for twin pregnancies 320 to 386/7 weeks

Jon Barrett; Elizabeth Aztalos; Andrew Willan; K.S. Joseph; B. Anthony Armson; Eileen Hutton; Alexander C. Allen; Arne Ohlsson; Sue Ross; Scott A. Farrell; Amiram Gafni; Nan Okun; Mary Hannah

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K.S. Joseph

University of British Columbia

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Mary E. Hannah

Sunnybrook Health Sciences Centre

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Julian N. Robinson

Brigham and Women's Hospital

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