Researchers with Tulane University may have found a way to detect preeclampsia, a dangerous pregnancy-related disorder, before it becomes life-threatening, according to a study published in the journal Scientific Reports.
The research could help prevent maternal and fetal deaths and other serious pregnancy complications. According to the researchers, the hypertensive disorder accounts for 14 percent of maternal deaths around the world.
The symptoms of preeclampsia, which typically occurs in the second or third trimester of pregnancy, include high blood pressure and protein in the mother's urine.
If it goes undetected, it can lead to eclampsia, which can result in seizures and comas, and can kill both mother and baby. Maternal deaths from the disorder are widely thought to be preventable.
In Louisiana, three of 47 — or about 6 percent — of confirmed maternal deaths reported between 2011 and 2016 were caused by preeclampsia or eclampsia, according to the Louisiana Department of Health.
The Tulane study, which was published online in late January, was led by Carolyn Bayer, an assistant professor of biomedical engineering, along with a team of graduate students and researchers with the university's School of Medicine and the School of Public Health and Tropical Medicine.
Bayer and the other researchers found that by using spectral photoacoustic imaging, a noninvasive technique already used on patients to detect some forms of cancer, they were able to spot a lowered blood supply to the placenta — a change associated with preeclampsia.
That change occurred before the onset of other telltale symptoms, including dangerously high blood pressure, severe headaches and dizziness.
Bayer said the study showed such screening or imaging "is a powerful preclinical tool" that has many promising applications for pregnant women.
“It provides new imaging techniques to look at the progression of the disease through gestation, which might be a better way to understand which patients need interventions to treat the preeclampsia," she said.
The Tulane study was conducted on rats. Bayer and other researchers took photoacoustic images of the placentas of normal pregnant rats and compared them to rats with induced preeclampsia in various stages of gestation.
Through the imaging, which is typically used to detect breast, ovarian and other types of cancers, the researchers were able to see that the disorder was restricting the blood supply to the tissues in the placenta, which in turn causes a shortage of oxygen needed for cellular function.
Two days after rats were induced with preeclampsia, their placentas were getting an average of 12 percent less oxygen than those of rats without the disorder, according to the study.
The imaging procedure used to detect early signs of preeclampsia in rats is considered especially promising for humans, researchers said, because it poses little to no risk to the fetus. Other detection methods for pregnancy complications use cordocentesis, a fetal blood sampling that is much more dangerous to the baby.
Dylan Lawrence, another researcher on the study, said it would be "fairly simple" and not too cost-prohibitive to integrate the imaging into current ultrasound systems, but that researchers are still developing technology to see deep into tissue to detect oxygen levels in human placentas.
The problem, Lawrence said, is that placentas can sometimes be deep in the uterine wall, but several labs — including those at Tulane — are working on making the imaging more sensitive.
Even though the disease was recognized nearly 2,000 years ago, the cause of preeclampsia is still not fully understood, according to the Preeclampsia Foundation.
And research has found that, in the United States, the number of reported cases of preeclampsia has increased in the last 20 years. Women who are pregnant before they turn 20 or after they turn 40 are more likely to have the condition, as are women who are obese or suffer from high blood pressure.
In 2014, almost 5 percent of all inpatient deliveries in the U.S. involved preeclampsia or eclampsia — a 21 percent increase from 2005, according to a brief published by the Agency for Healthcare Research and Quality, part of the U.S. Department of Health and Human Services.