J G Ray

University of Toronto, Toronto, Ontario, Canada

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Publications (3)2.82 Total impact

  • J G Ray, M L Urquia
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    ABSTRACT: Objective:To determine the risk of stillbirth between 20 to 41 weeks gestation, at highly detailed weight percentiles, including extreme degrees of small (SGA) and large (LGA) for gestational age birth weight.Study Design:We completed a population-based study of all births in Ontario, Canada between 2002 and 2007. We included 767 016 liveborn and 4,697 stillborn singletons delivered between 20 and 41 weeks gestation. Smoothed birthweight percentile curves were generated for males and females, combining livebirths and stillbirths. Quantile regression was used to calculate sex-specific absolute birthweight differences and 95% confidence intervals (CI) between stillborns vs liveborns at various gestational ages. Logistic regression was used to calculate the odds ratios (OR) for stillbirth at various sex-specific birthweight percentiles, including <1st and 99th percentile. OR were adjusted for maternal age and parity.Result:At the 10th percentile, stillborns weighed significantly less than liveborns starting at 24 weeks gestation. By 32 weeks, this difference was 590 g (95% CI 430 to 750) for males and 551 g (95% CI 345 to 448) for females. A reverse J-shaped association was observed between birthweight percentile and risk of stillbirth across all gestational ages. Relative to the 40th to 60th percentile referent, the adjusted OR for stillbirth was 9.63 (95% CI 8.39 to 11.06) at a birth weight <1st percentile. At 99th percentile, the adjusted OR was 2.24 (95% CI 1.76 to 2.86). The risk of stillbirth at extreme birthweight percentiles was robustly observed across gestational ages.Conclusion:Substantial birthweight differences exist between stillborns and newborns. As a possible hallmark of impending intrauterine death, severe SGA and LGA may each be potential targets for future stillbirth prevention initiatives.Journal of Perinatology advance online publication, 17 May 2012; doi:10.1038/jp.2012.60.
    Journal of perinatology: official journal of the California Perinatal Association 05/2012; · 1.59 Impact Factor
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    ABSTRACT: Non-alcoholic fatty liver disease (NAFLD) is associated with a higher risk of cardiovascular disease, but no data exist about the relation between NAFLD and adverse outcomes in persons with acute coronary syndromes (ACS). We evaluated elevated serum alanine aminotransferase (ALT) as a marker of NAFLD, in association adverse outcomes following ACS. We conducted a retrospective cohort study of participants enrolled in the Global Registry of Acute Coronary Events (GRACE) admitted for ACS to St Michael's Hospital, Toronto, between 1999 and 2007. Multivariable linear regression was used to determine the change in maximum measured cardiac troponin I (cTnI) per each 1 IU/l increase in serum ALT concentration. The association between an elevated ALT >90th centile, and adverse outcomes in-hospital and at 6 months were calculated using multiple logistic regression analyses, adjusting for age, sex, body mass index, serum creatinine, glucose, triglycerides and LDL-C, as well as chronic statin or other lipid-lowering agent use. 528 participants were included. Each 1 IU/l increase in ALT was associated with an increase in maximum measured cTnI of 0.16 µg/l (95% CI 0.10 to 0.22). An elevated ALT concentration >90th percentile was associated with a maximum measured cTnI in the highest quartile (adjusted OR 7.07, 95% CI 1.83 to 27.37). An elevated ALT >90th percentile was also significantly associated with all-cause mortality in-hospital, and up to 6 months after discharge (adjusted OR 8.96, 95% CI 3.28 to 24.49). NAFLD, determined by an elevated serum ALT, is associated with a higher risk of adverse outcomes in persons with ACS. Whether ALT is a valid and independent prognostic marker in ACS remains to be determined.
    Heart Asia. 02/2012; 4(1):137-140.
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    ABSTRACT: Information on newborn gestational age (GA) is essential in research on perinatal and infant health, but it is not always available from administrative databases. We developed and validated a GA prediction model for singleton births for use in epidemiological studies. Derivation of estimated GA was calculated based on 130 328 newborn infants born in Ontario hospitals between 2007 and 2009, using linear regression analysis, with several infant and maternal characteristics as the predictor (independent) variables. The model was validated in a separate sample of 130 329 newborns. The discriminative ability of the linear model based on infant birth weight and sex was reasonably approximate for infants born before the 37th week of gestation (r2 = 0.67; 95% CI: 0.65-0.68), but not for term births (37-42 weeks; r2 = 0.12; 95% CI: 0.12-0.13). Adding other infant and maternal characteristics did not improve the model discrimination. Newborn gestational age before 37 weeks can be reasonably approximated using locally available data on birth weight and sex.
    Chronic Diseases and Injuries in Canada 06/2011; 31(3):103-8. · 1.22 Impact Factor

Publication Stats

3 Citations
2.82 Total Impact Points


  • 2012
    • University of Toronto
      Toronto, Ontario, Canada
    • McMaster University
      • Faculty of Health Sciences
      Hamilton, Ontario, Canada
  • 2011
    • St. Michael's Hospital
      Toronto, Ontario, Canada