Prevalence of diabetes in pregnancy expected to continue rising in Canada

Key takeaways:

• Type 1, type 2 and gestational diabetes rates rose since 2005 in Canada, especially for those aged 15 to 19 years.
• Pregnancies with vs. without any diabetes had higher hypertension and cesarean section rates.

From 2005 to 2019 in Canada, type 1, type 2 and gestational diabetes prevalence in pregnancy steadily increased and is expected to continue to rise as more women with overweight conceive, researchers reported.

“Recent estimates show that the prevalence of type 2 diabetes and gestational diabetes is increasing globally. A rise in type 1 diabetes is being documented internationally in younger populations,” Chantal R.M. Nelson, PhD, senior epidemiologist in the maternal and infant health section at the Centre for Surveillance and Applied Research at the Public Health Agency of Canada, and colleagues wrote in BMC Pregnancy and Childbirth. “Although there are national reports on diabetes during pregnancy, few distinguish between preexisting diabetes and gestational diabetes.”

Nelson and colleagues analyzed cross-sectional data from the Canadian Institute of Health Information hospitalization discharge abstract database on 4,320,778 hospital deliveries from 2005 to 2019. Researchers linked maternal delivery and birth records and calculated prevalence of type 1, type 2 and gestational diabetes.

For every 1,000 deliveries, researchers observed a relative increase of 25% for type 1 diabetes (2.4 to 3), 189% for type 2 diabetes (2.7 to 7.8), 162.7% for gestational diabetes not including data from British Columbia (36.5 to 95.9) and 153% for gestational diabetes including data from British Columbia (41.2 to 104.3).

The youngest population of women and girls aged 15 to 19 years had the largest increases in type 1, type 2 and gestational diabetes. From 2005 and 2019, for every 1,000 births, the younger population had a relative increase of 92.9% for type 1 diabetes (1.4 to 2.7), 330% for type 2 diabetes (1 to 4.3), 291% for gestational diabetes not including data from British Columbia (10.6 to 38.2) and 260% for gestational diabetes including data from British Columbia (9.9 to 37.8).

Compared with pregnancies without diabetes, pregnancies with type 1, type 2 or gestational diabetes had higher rates of hypertension and cesarean delivery, respectively.

In addition, pregnancies with type 1, type 2 or gestational diabetes vs. without any form of diabetes also had higher rates of adverse infant outcomes including:

• major congenital anomalies;
• preterm birth at less than 32 weeks’ gestation;
• preterm birth between 32 and 36 weeks’ gestation;
• large for gestational age; and
• stillbirth, respectively.

“Continued national surveillance of diabetes during pregnancy is needed to better inform and guide prevention efforts, as the rates of type 1 diabetes and type 2 diabetes and gestational diabetes are expected to continue to rise due to the increased trend of an older, and more obese maternal population in Canada,” the researchers wrote. “Additionally, the increase in diabetes during pregnancy amongst the younger population warrants particular attention.”