Trends in incidence of diabetes in pregnancy and serious perinatal outcomes: a large, population-based study in Ontario, Canada, 1996-2010.
OBJECTIVE
Women with diabetes in pregnancy have high rates of pregnancy complications. Our aims were to explore trends in the incidence of diabetes in pregnancy and examine whether the risk of serious perinatal outcomes has changed.


METHODS
We performed a population-based cohort study of 1,109,605 women who delivered in Ontario, Canada, between 1 April 1996 and 31 March 2010. We categorized women as gestational diabetes (GDM) (n = 45,384), pregestational diabetes (pre-GDM) (n = 13,278), or no diabetes (n = 1,050,943). The annual age-adjusted rates of diabetes in pregnancy were calculated, and rates of serious perinatal outcomes were compared between groups and by year using Poisson regression.


RESULTS
The age-adjusted rate of both GDM (2.7-5.6%, P < 0.001) and pre-GDM (0.7-1.5%, P < 0.001) doubled from 1996 to 2010. The rate of congenital anomalies declined by 23%, whereas the rate of perinatal mortality did not change significantly. However, compared with women with no diabetes, women with pre-GDM and GDM faced an increased risk of congenital anomalies (relative risk 1.86 [95% CI 1.49-2.33] and 1.26 [1.09-1.45], respectively), and perinatal mortality remained elevated in women with pre-GDM (2.33 [1.59-3.43]).


CONCLUSIONS
The incidence of both GDM and pre-GDM in pregnancy has doubled over the last 14 years, and the overall burden of diabetes in pregnancy on society is growing. Although congenital anomaly rates have declined in women with diabetes, perinatal mortality rates remain unchanged, and the risk of both remains significantly elevated compared with nondiabetic women. Increased efforts are needed to reduce these adverse outcomes.
Department of Medicine, University of Toronto, Toronto, Ontario, CanadaInstitute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, CanadaInstitute for Clinical Evaluative Sciences, Toronto, Ontario, CanadaDepartment of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, CanadaDivision of Endocrinology and Metabolism, Mount Sinai Hospital, Toronto, Ontario, Canada d.feig@utoronto.ca.
Denice S
DS
Feig
Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
Jeremiah
J
Hwee
Department of Medicine, University of Toronto, Toronto, Ontario, CanadaInstitute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, CanadaInstitute for Clinical Evaluative Sciences, Toronto, Ontario, CanadaDivision of Endocrinology and Metabolism, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
Baiju R
BR
Shah
Department of Medicine, University of Toronto, Toronto, Ontario, CanadaInstitute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, CanadaInstitute for Clinical Evaluative Sciences, Toronto, Ontario, CanadaKeenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, CanadaDivision of Endocrinology and Metabolism, St. Michael's Hospital, Toronto, Ontario, Canada.
Giliian L
GL
Booth
Department of Medicine, University of Toronto, Toronto, Ontario, CanadaInstitute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, CanadaInstitute for Clinical Evaluative Sciences, Toronto, Ontario, CanadaKeenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, CanadaDivision of Internal Medicine, St. Michael's Hospital, Toronto, Ontario, Canada.
Arlene S
AS
Bierman
Department of Medicine, University of Toronto, Toronto, Ontario, CanadaInstitute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, CanadaInstitute for Clinical Evaluative Sciences, Toronto, Ontario, CanadaWomen's College Research Institute and the Division of Endocrinology and Metabolism, Women's College Hospital, Toronto, Ontario, Canada.
Lorraine L
LL
Lipscombe
D000293:Adolescent; D000328:Adult; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D015331:Cohort Studies; D000013:Congenital Abnormalities / Q000453:epidemiology*; D016640:Diabetes, Gestational / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D008875:Middle Aged; D054238:Perinatal Mortality / Q000639:trends*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011256:Pregnancy Outcome; D055815:Young Adult