New research published in the Canadian Medical Association Journal (CMAJ) indicates an increase in hypertensive disorders of pregnancy rates in Canada, but a decline in related health conditions.
Hypertensive disorders of pregnancy (HDP) include chronic hypertension, gestational hypertension, and preeclampsia. They affect 5%-10% of pregnancies globally and cause over 50,000 maternal and 500,000 fetal and infant deaths every year.
In this study, researchers looked at the data of over 2.8 million births in hospitals between 2012 and 2021. They wanted to understand trends in HDP and related outcomes.
When researchers observed the collected data, they found an increase in HDP rates from 6.1% to 8.5%, with a relative increase of 40%. Pre-existing hypertension also increased temporally and gestationally from 0.6% to 0.9%, preeclampsia from 1.2% to 2.6% and gestational hypertension increased from 3.9% to 5.1%
The researchers found that rates of high blood pressure disorders were higher in females under 20 and over 34 years old. They also observed differences in rates across different provinces and territories. Northwest Territories and Ontario had the lowest rates of HDP. On the other hand, Newfoundland and Labrador had the highest rates of HDP.
The study found that adjusting for risk factors like maternal age, previous livebirths, pre-existing diabetes, and rural residence did not significantly affect the risk of HDP. But the authors did not account for factors like body mass index (BMI) that is a known risk factor for hypertension, including during pregnancy that could explain the rise in HDP.
The percentage of females aged 18-34 years who are overweight or obese in Canada increased from 41% to 48% between 2015 and 2021. Researchers also found that provinces with more overweight and obese women also had more cases of high blood pressure during pregnancy.
The authors of this study said that the clinical management of high blood pressure during pregnancy has improved over time and that reduced the risk of negative outcomes. They also emphasize the importance of regularly measuring blood pressure during prenatal visits and using evidence-based antihypertensive therapy.
Dr. Catherine Varner, deputy editor of CMAJ, said that the increasing number of high-risk obstetrical patients should prompt health policymakers to prioritize accessible and specialized obstetrical care.
Females with hypertension and other disorders need to be monitored after giving birth. But there is a shortage of qualified healthcare providers.
This study highlights the need for more obstetrical care providers with expertise in caring for high-risk patients. The current number of obstetricians is unable to meet the needs of the growing population with more health issues. Hence, team-based maternity care may be a solution and can effectively reduce the risk of HDP.
Reference Link:
Trends in rate of hypertensive disorders of pregnancy and associated morbidities in Canada: a population-based study (2012–2021), Canadian Medical Association Journal (2024).
