Sara McGinnis was pregnant with her second child and something felt off. Her body was swollen. She was tired and dizzy.

Her husband, Bradley, said she had told her doctor and nurses about her symptoms and even went to the emergency room when they worsened. But, he said, what his wife was told in response was “ ‘It’s summertime and you’re pregnant.’ That haunts me.”

Two days later, Sara had a massive stroke followed by a seizure. It happened on the way to the hospital, where she was headed again because of a splitting headache.

Sara, from Kalispell, Montana, never met her son, Owen, who survived through an emergency delivery and has her oval eyes and thick dark hair. She died the day after he was born.

Sara had eclampsia, a sometimes deadly pregnancy complication caused by persistent high blood pressure, also known as hypertension. High blood pressure makes the heart work in overdrive, which can damage organs.

Sara died in 2018. Today, more pregnant people are being diagnosed with dangerously high blood pressure, a finding that could save their lives. Recent studies show that the rates of newly developed and chronic maternal high blood pressure have roughly doubled since 2007. Researchers say the jump in cases is likely due in part to more testing that discovers the conditions.

But that’s not the whole story. Data shows that the overall maternal mortality rate in the United States is also climbing, with high blood pressure one of the leading causes.

Medical experts are trying to stem the tide.

In 2022, the American College of Obstetricians and Gynecologists lowered the threshold for when doctors should treat pregnant and postpartum patients for high blood pressure. And federal agencies offer training in best practices for screening and care. Federal data shows that maternal deaths from high blood pressure declined in Alaska and West Virginia after implementation of those guidelines.

But applying those standards to everyday care takes time, and hospitals are still working to incorporate practices that might have saved Sara’s life.

In Montana, which last year became one of 35 states to implement the federal patient safety guidelines, more than two-thirds of hospitals provided timely care to patients, said Annie Glover, a senior research scientist with the Montana Perinatal Quality Collaborative. Starting in 2022, just over half of hospitals met that threshold.

“It just takes some time in a hospital to implement a change,” she said.

High blood pressure can damage a person’s eyes, lungs, kidneys or heart, with consequences long after pregnancy. Preeclampsia — consistent high blood pressure in pregnancy — can also lead to a heart attack. The problem can develop from inherited or lifestyle factors: For example, being overweight predisposes people to high blood pressure. So does older age, and more people are having babies later in life.

Black and Indigenous people are far more likely than the general population to develop and die from high blood pressure in pregnancy.

“Pregnancy is a natural stress test,” said Natalie Cameron, a physician and an epidemiologist with Northwestern University’s Feinberg School of Medicine who has studied the rise in high blood pressure diagnoses. “It’s unmasking this risk that was there all the time.”

But pregnant women who don’t fit the typical risk profile are also getting sick, and Cameron said more research is needed to understand why.

Mary Collins, 31, of Helena, Montana, developed high blood pressure while pregnant this year. Halfway through her pregnancy, Collins still hiked and attended strength training classes. Yet she felt sluggish and was gaining weight too rapidly while her baby’s growth slowed drastically.

Collins said she was diagnosed with preeclampsia after she asked an obstetrician about her symptoms. Just before that, she said, the doctor had said all was going well as he checked her baby’s development.

“He pulled up my blood pressure readings, did a physical assessment and just looked at me,” Collins said. “He was like, ‘Actually, I’ll take back what I said. I can easily guarantee that you’ll be diagnosed with preeclampsia during this pregnancy, and you should buy life flight insurance.’ ”

Indeed, Collins was airlifted to Missoula, Montana, for the delivery; her daughter, Rory, was born two months early. The baby had to spend 45 days in a neonatal intensive care unit. Rory, now about 3 months old, and Collins are still recovering.

The typical cure for preeclampsia is delivering the baby. Medication can help prevent seizures and speed up the baby’s growth to shorten pregnancy if the health of the mother or fetus warrants a premature delivery. In rare cases, preeclampsia can develop soon after delivery, a condition researchers still don’t fully understand.

Wanda Nicholson, chair of the U.S. Preventive Services Task Force, an independent panel of experts in disease prevention, said steady monitoring is needed during and after a pregnancy to truly protect patients. Blood pressure “can change in a matter of days, or in a 24-hour period,” Nicholson said.

And symptoms aren’t always clear-cut.

That was the case for Emma Trotter. Days after she had her first child in 2020 in San Francisco, she felt her heartbeat slow. Trotter said she called her doctor and a nurse helpline, and both told her she could go to an emergency room if she was worried but advised her that it wasn’t needed. So she stayed home.

In 2022, about four days after she delivered her second child, her heart slowed again. That time, the care team in her new home of Missoula checked her vitals. Her blood pressure was so high the nurse thought the monitor was broken.

“ ‘You could have a stroke at any second,’ ” Trotter recalled her midwife telling her before sending her to the hospital.

Stephanie Leonard, an epidemiologist at Stanford University School of Medicine who studies high blood pressure in pregnancy, said more monitoring could help with complex maternal health problems.

“Blood pressure is one component that we could really have an impact on,” she said. “It’s measurable. It’s treatable.”

In 2015, the federal Health Resources and Services Administration worked with the American College of Obstetricians and Gynecologists to roll out best practices to make birth safer, including a specific guide to scan for and treat high blood pressure. Last year the federal government boosted funding for such efforts to expand implementation of those guides.

“So much of the disparity in this space is about women’s voices not being heard,” said Carole Johnson, head of the health resources agency.

Katlin Tonkin is one of the nurses training Montana medical providers on how to make birth safer. She knows how important it is from experience: In 2018, Tonkin was diagnosed with severe preeclampsia when she was 36 weeks pregnant, weeks after she had developed symptoms. Her emergency delivery came too late and her son Dawson, who hadn’t been getting enough oxygen, died soon after his birth.

Tonkin has since had two more sons, both born healthy, and she keeps photos of Dawson, taken during his short life, throughout her family’s home.

“I wish I knew then what I know now,” she said. “We have the current evidence-based practices. We just need to make sure that they’re in place.”