The only cure right now is to end the pregnancy
That is the hard truth at the center of severe preeclampsia. Doctors can control the blood pressure and prevent seizures, but none of that fixes the disease. When it turns dangerous, the fix is delivery, often weeks early, which trades the mother’s risk for a premature baby’s. It affects 3% to 8% of pregnancies worldwide, and for the severe cases it is one of the biggest threats to mothers and newborns anywhere.
Part of the reason there is no real treatment is that the disease has long been pinned on one organ: the placenta. A study published in Science Advances on July 24, 2026, argues that view is too small. By reading the genes of individual cells across the pregnancy, a team at University College London and UCLH found the mother’s own immune system tangled up in the disease, not just the placenta. That shift, from one broken organ to a body-wide problem, is where new targets might come from.
Reading 293,000 cells one at a time
The researchers used two techniques that let you see what individual cells are actually doing, single-cell RNA sequencing and spatial transcriptomics, on roughly 293,000 cells. They compared 20 pregnancies: 10 with severe preeclampsia and 10 healthy controls, sampled between 25 and 37 weeks. Out of all that, they sorted 27 distinct cell populations.
The clearest early failure was in a set of fetal cells called extravillous trophoblasts. Their normal job is to invade the uterine wall and remodel its arteries so blood pours into the placenta. In the affected pregnancies there were fewer of them and they did not reach deep enough. The result is a placenta running short on blood and oxygen, stressed and struggling, which sets off everything downstream.
The distress signals the placenta sends out
A starved placenta does not suffer quietly. It releases proteins and hormones into the mother’s blood, and two of them stood out in this study.
The first is a gene called FLT1, long tied to preeclampsia, which makes a receptor that jams up normal blood-vessel growth. The second is more of a surprise: leptin, the hormone most people know as an appetite regulator. The placenta was over-producing it, and the researchers think it is acting as a messenger, carrying the placenta’s distress out to the mother’s blood vessels and immune cells. That is the bridge from a local placental problem to a whole-body illness.
The mother’s immune system joins in
The most novel part sits outside the placenta entirely. In the mothers with severe disease, certain immune cells in the blood (monocytes and macrophages) had ramped up something called Type I interferon signaling, a pathway the body normally fires to fight off viruses. Here there is no virus. It appears instead to be a fingerprint of severe disease, and because it shows up in the blood, it is the kind of thing a future test could look for.
Alongside that, the cells showed signs of mitochondrial dysfunction and oxidative stress, meaning the tiny power packs inside cells were faltering and leaving damaging byproducts behind. This was most pronounced in early-onset cases, the ones striking at or before 34 weeks, which also tend to be the most dangerous.
What this could change, and the voices behind it
None of this is a treatment yet, but it points at levers that current care does not touch. Abdulla Al-Khan, MD, of Hackensack University Medical Center, said the work moves the field toward therapies aimed at the disease’s biology rather than just its symptoms. Sara Hillman, a consultant at UCLH and UCL, suggested the pathways it uncovered might eventually let doctors reach for existing drugs to help the severe cases, the ones that carry the highest risk of death.
That is the real prize here. If leptin, interferon, or mitochondrial stress can be targeted, the goal is a future where “deliver the baby now” is not the only tool.
Hold it loosely
This is an early map, and it deserves early-map skepticism. It rests on 20 pregnancies, which is small, so the findings need to hold up in much larger, multi-center studies before they touch clinical practice. The samples also ran from 25 to 37 weeks, and the biology of very early preeclampsia may not look the same as cases later in the third trimester.
What comes next
The most useful near-term question is whether that interferon signature in maternal blood can become a real test. If it can be caught early with a routine blood draw, it could flag at-risk pregnancies for closer watching before things turn severe. The team also plans to test these pathways in lab models and to check whether drugs that already target mitochondrial stress or interferon signaling could be repurposed here.
If you are pregnant and worried about preeclampsia, none of this changes today’s advice: keep up with blood-pressure checks and prenatal visits, and flag severe headaches, vision changes, or sudden swelling to your clinician early. This research is about where treatment is heading, not what is on the table right now.
Sources:
- Medscape, “Study Offers New Clues to Severe Preeclampsia, Points to Future Treatment Targets” (https://www.medscape.com/viewarticle/study-offers-new-clues-severe-preeclampsia-points-future-2026a1000pb4)
- News-Medical, “Study discovers new therapeutic targets for severe preeclampsia” (https://www.news-medical.net/news/20260724/Study-discovers-new-therapeutic-targets-for-severe-preeclampsia.aspx)
Disclaimer: This article is for general information only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about any medical condition or before making health decisions.