Pregnancy Hypertensive Disorders Need New Model of Care

The rate of hypertensive disorders of pregnancy (HDP) is rising among women in Canada, while the morbidity associated with them is falling, according to findings of a study published in the Canadian Medical Association Journal (CMAJ). Experts say that new ways are needed to improve monitoring for HDPs and to ensure women have access to appropriate obstetric care.

The population-based study of close to three million hospital births in Canada between 2012 and 2021 found that the rate of HDPs rose 2.4% during that time period. 

However, rates of commonly seen complications associated with HDPs, including early preterm delivery, intrauterine fetal death, maternal hospital length of stay for 7 days or longer, admission to the maternal intensive care unit, severe hemorrhage, and severe maternal morbidity, trended downward.

Hypertensive disorders of pregnancy include chronic hypertension, gestational hypertension, and preeclampsia or eclampsia. They affect 5%-10% of pregnancies worldwide, and cause more than 50,000 maternal deaths and 500,000 deaths in fetuses and infants every year. 

“Contemporary rates of hypertension in pregnancy are lacking for Canada, as is our knowledge about how hypertension in pregnancy has negatively impacted the mother and her fetus,” senior author, Joel G. Ray, MD, obstetrical medicine specialist at St. Michael’s Hospital, Toronto, Ontario, Canada, told Medscape Medical News. “These issues prompted us to do this study.”

Real-World Data

The study included 2,804,473 hospital births in Canada but not from the province of Québec. 

Analysis of the data showed that the rate of any HDP increased from 6.1% to 8.5% between 2012 and 2021. The rate of preeclampsia increased from 1.6% to 2.6%.

Among women with HDP, rates of Cesarean delivery rose from 42.0% in 2012 to 44.3% in 2021. 

Rates of HDP were higher in women aged under 20 years and over 34 years. 

There was also variability in rates across provinces and territories, with the Northwest Territories (6.5%) and Ontario (6.9%) having the lowest rates, and Newfoundland and Labrador with the highest rate (10.7%). 

“We need to keep figuring out ways to better manage blood pressure in pregnancy using existing, effective, and safe medications,” Ray said.

“We also need to optimize the message to women about the importance of taking low-dose aspirin prophylaxis starting at 12-18 weeks of pregnancy, specifically in women at higher risk of preeclampsia. We also need to improve the way we monitor for new-onset hypertension and preeclampsia soon after birth,” he said.

Ray would like to see a handout created for all new mothers.

The handout would describe, in clear and simple terms, the typical symptoms of preeclampsia. It would encourage new mothers to go to their local pharmacy to check their blood pressure about 1-3 days after hospital discharge following delivery. If the systolic blood pressure is above 150 mm Hg or she has symptoms of preeclampsia, she would be encouraged to contact her family physician, midwife, or obstetrician, or otherwise seek help at her local hospital, he explained.

Emergency Department Alternatives Needed

In a related editorial, Catherine Varner, MD, an emergency physician in Toronto and deputy editor of CMAJ, wrote that the “growing population of high-risk obstetrical patients should alert health policy makers that more people need easily accessed, specialized obstetrical care.” 

In an interview with Medscape Medical News, Varner added that the study “is another indicator that people are coming into their reproductive lives with more medical problems than they did a generation ago and our healthcare system is not prepared for that, as evidenced by the number of postpartum patients who find themselves having to go to an emergency department their first week postpartum.”

She pointed out that Canada has higher rates of emergency department utilization in the early postpartum period than its peer countries. Most of those patients do not require hospitalization, “which means that many of these concerns could have been managed in an out-patient clinic,” Varner said.

She explained that, frequently, emergency departments visits are from women who have been instructed to monitor their blood pressure and notice it has started rising. But these women might not have access to a family doctor or an obstetrician and don’t have anywhere but an emergency department to seek care.

“An emergency department waiting room is a terrible place to be for a new parent with an infant to feed. In addition to concerns about infant feeding, we also worry about an infant acquiring an infection in a crowded waiting room,” she added.

Models of care that include midwives could help fill in some gaps to better serve the postpartum population, Varner said. 

“It would have to be team based. We simply do not have enough high-risk obstetrical care providers to look after our current high-risk population, so we will be reliant on team-based models of care which could conceivably provide the timely care that these patients need both during and after pregnancy,” she said.

The study was funded in part by the Public Health Agency of Canada. Dzakpasu, Ray, and Varner report no relevant financial relationships.