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The incidence of gestational diabetes and pre-gestational diabetes in pregnancy has doubled over the last 14 years


The rate of both gestational diabetes (GDM) and pre-gestational diabetes (pre-GDM) doubled from 1996 to 2010, according to a study by researchers at the Institute for Clinical Evaluative Sciences (ICES) and Mount Sinai Hospital.

“By 2010, almost one in every 10 pregnant women over the age of 30 had diabetes in pregnancy,” said Dr. Denice Feig, a staff physician in the Division of Endocrinology at Mount Sinai Hospital and head of its Diabetes in Pregnancy Program and an adjunct scientist at ICES.

In this large, population-based study, published today in the journal Diabetes Care, researchers examined 1,109,605 women who delivered in Ontario between April 1, 1996 and March 31, 2010. Although congenital anomaly rates declined over the study period by 20 to 23 per cent in the children of women with GDM and pre-GDM respectively, perinatal mortality rates remained unchanged, and the risk of both remained significantly elevated compared to women without diabetes. In 2010, compared to women without diabetes, infants of women with pre-GDM had a two-fold higher risk of congenital anomalies while women with GDM had a 26 per cent higher risk of having an infant with a congenital anomaly.

Young women with pre-GDM were more likely to have infants with congenital anomalies than their counterparts without diabetes. This may reflect reduced pregnancy planning in this group.  Increased efforts to educate young women with diabetes, even those in their teens, regarding the need to seek preconception care is needed, and may improve rates of anomalies in the children of these young women. 

The authors stress that increased efforts are also needed to educate and empower women with type 2 diabetes, who have the lowest rates of attending for preconception care. Women with type 2 diabetes tend to be of lower socioeconomic status, and include many ethnic minorities and new immigrants.

The authors found that living in a rural community increased the risk of both congenital anomalies and perinatal mortality in infants of women with pre-GDM.  Decreased education and awareness regarding pregnancy planning, along with reduced access to care, may be playing a role in this observed risk.  Seeing an obstetrician reduced the risk of mortality in infants of women with both GDM and pre-GDM.

With the steadily increasing rates of diabetes in pregnancy, and the serious nature of perinatal complications, the burden of these high risk pregnancies is increasing. 

“While we have come a long way in improving care for women with diabetes in pregnancy, further efforts are needed to decrease the prevalence of these serious perinatal outcomes in women with diabetes through improved preconception and perinatal care,” said Feig. 

As part of her clinical work in Leadership Sinai’s Centre for Diabetes, Dr. Feig cares for over 250 pregnant women annually.  Women with pre-existing diabetes receive preconception counseling and care to optimize glycemic control and diabetes complications prior to pregnancy. During pregnancy Dr. Feig follows patients closely, in collaboration with the high risk obstetric team. Women with gestational diabetes are seen by Dr. Feig and her multi-disciplinary team of diabetes nurses and dieticians. Women are given nutritional advice along with self blood glucose monitoring education, while being counseled regarding their postpartum risk of diabetes and strategies for prevention.

Mount Sinai’s researchers rank #1 by citations worldwide for diabetes research compared to other medical research institutes.

Authors: Denice S Feig MD, Jeremiah Hwee MSc, Baiju R Shah MD, Giliian L Booth MD, Arlene S Bierman MD, Lorraine L Lipscombe MD.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.

For the latest ICES news, follow us on Twitter: @ICESOntario

Mount Sinai Hospital is as an internationally recognized 442-bed acute care academic health sciences centre affiliated with the University of Toronto that is dedicated to delivering the best medicine and best patient experience. It is focused on excellence in patient and family-centred care, innovative education and leading-edge research. Clinical strengths include women’s and infants’ health, chronic disease management, specialized cancer, emergency medicine, and geriatrics. The hospital has been designated with Exemplary Status from Accreditation Canada and every aspect of patient care is anchored in a rigorous quality plan and monitoring of safety and quality goals. Mount Sinai’s Lunenfeld-Tanenbaum Research Institute ranks in the top ten biomedical research institutes in the world. The Hospital is considered to be a top employer in Canada, receiving multiple awards for its employment and culture centred programs.  www.mountsinai.ca.


  • Sally Szuster
  • Mount Sinai Hospital
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