Despite causing over 70,000 maternal deaths every year, the root causes of pre-eclampsia, a life-threatening pregnancy complication, remain a mystery. This condition, characterized by dangerously high blood pressure and organ damage, has left medical experts searching for answers.
One of the many women who experienced the shocking impact of pre-eclampsia is Allyson Felix, an athlete known for her stellar track and field career, including seven Olympic gold medals and 14 world championship titles. Felix, who meticulously cared for her body throughout her career, assumed her pregnancy would be smooth sailing. But at a routine check-up at 32 weeks, she received a devastating diagnosis: severe pre-eclampsia. She was immediately hospitalised, and her daughter Camryn was delivered via emergency C-section two months early.
"All my life, I've taken care of my body; it's been my tool and has never failed me. I was expecting a beautiful, natural birth after all the hypnobirthing classes," says Felix. "But that routine check-up changed everything. It was terrifying."
While Felix and her daughter were eventually able to go home, Felix remains acutely aware of others who haven't been so fortunate. In 2023, her teammate Tori Bowie, a world 100m champion and relay gold medallist, tragically died from childbirth complications linked to pre-eclampsia. She was only 32.
Unravelling the Pre-Eclampsia Enigma
Pre-eclampsia claims the lives of over 70,000 mothers and 500,000 foetuses every year. This condition, often striking without warning, can occur at any stage of pregnancy or even postpartum. Early-onset pre-eclampsia occurs before 34 weeks, while some women experience it later, and postpartum pre-eclampsia strikes after childbirth.
While researchers have uncovered some clues, the condition remains largely unexplained. Excessive inflammation in the uterus disrupts communication between the mother's body and the foetus, impairing the reshaping of blood vessels that form the placenta. This abnormal blood flow interferes with the mother’s ability to regulate blood pressure, gradually leading to hypertension and pre-eclampsia.
“When a woman becomes pregnant, her heart has to pump extra blood for the baby and placenta,” says Ian Wilkinson, professor of therapeutics at the University of Cambridge. "In a normal pregnancy, blood flow increases by one-and-a-half to two times, but in pre-eclampsia, the body struggles to manage this increased demand."
The Disproportionate Impact on Black Women
Black women face an even greater risk, with rates of pre-eclampsia up to 60% higher than in white women. While some researchers attribute this disparity to socioeconomic factors like access to healthcare and nutrition, others believe structural racism also plays a role. According to Dr. Garima Sharma, director of cardio-obstetrics at Inova Health System, “There’s structural racism where certain communities don’t have the same access to early interventions and screenings, but that doesn’t fully explain why the condition starts in the first place.”
Despite known risk factors such as age, ethnicity, and medical history, predicting who will develop pre-eclampsia remains difficult. “The accuracy of these clinical risk factors is poor,” Sharma notes.
New Diagnostics Offer Hope
While doctors treating other diseases can often take biopsies for analysis, this isn't feasible during pregnancy. Researchers have instead focused on identifying biomarkers in the blood that signal potential problems. One such biomarker is a protein called soluble fms-like tyrosine kinase 1 (sFlt-1), which accumulates to 100 times its normal levels in women developing pre-eclampsia.
In 2022, Thermo Fisher Scientific received FDA approval for a diagnostic tool that measures sFlt-1 levels to predict whether a pregnant woman showing early signs of hypertension will develop severe pre-eclampsia within the next two weeks. This tool has been proven effective, allowing healthcare providers to take preventive measures before symptoms worsen.
While this diagnostic test is a promising advancement, Cindy Anderson, professor of maternal-infant health at Ohio State University, emphasises the need for earlier detection. “If we could detect these warning signs before the placenta is fully developed, it might still be possible to prevent the condition entirely,” she says.
Innovations on the Horizon: Placenta on-a-Chip
To improve understanding of the disease, researchers in Sydney have developed a "placenta on-a-chip"—a model made from placental cells that mimics the processes that occur during early pre-eclampsia. This breakthrough allows scientists to study the condition outside the human body and could lead to the discovery of new biomarkers and treatments.
"With this model, we can understand what’s happening to placental cells under conditions like inflammation and restricted blood vessel development, which precede pre-eclampsia," says Lana McClements, associate professor at the University of Technology Sydney.
This innovation could also help researchers test new treatments. One promising area of research involves drug repurposing, where existing medications are used to treat new conditions. For example, drugs commonly used to treat indigestion, such as proton pump inhibitors, may help reverse the inflammatory processes that drive pre-eclampsia.
A Race Against Time
In the battle against pre-eclampsia, time is of the essence. Currently, the only recommended treatment for women at high risk is low-dose aspirin, which reduces the risk of developing pre-eclampsia in about 60% of cases. However, this leaves a significant number of women vulnerable.
New treatments and technologies offer hope, but more investment is needed to develop effective therapies and improve diagnostics. "Two out of three women who experience pre-eclampsia will die prematurely from heart disease or other cardiovascular complications,” McClements warns. "We need to find new treatments that can prevent both pregnancy-related and post-pregnancy diseases."
The stakes are high. With advancements like the placenta-on-a-chip and innovative drugs like CBP-4888, which inhibits the production of sFlt-1, there is potential to change the course of this devastating condition. Researchers are hopeful that these breakthroughs will save lives, especially in vulnerable populations, including women of colour.
The Way Forward
Pre-eclampsia remains a deadly enigma, but researchers are making strides toward understanding and preventing the condition. As awareness grows and new technologies emerge, there is hope that more women will have safe, healthy pregnancies free from the risks posed by this life-threatening condition.
"We all come from pregnancy," McClements says. "Women are half of the population, and mothers to the other half. Finding solutions to pre-eclampsia will benefit us all."
Note: Originally published by https://www.bbc.com/
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