Preeclampsia is a life-threatening pregnancy complication that affects  approximately 5% of women, and is the leading cause of pregnancy-related death. New findings by Technion researchers indicate that early-onset and late-onset preeclampsia are, in fact, not the same disease. Understanding these findings could lead to better diagnosis, treatment, and survival rates.

Preeclampsia is often detected during routine prenatal visits as new-onset hypertension. It is caused by abnormalities in the placenta – the organ of the fetus that enables the transfer of oxygen and nutrients from the mother to the fetus. 

In severe cases, preeclampsia may damage the mother’s organs, such as the kidneys, liver, or the brain. Late-onset preeclampsia usually begins in the last few weeks of pregnancy, and is less severe than early-onset preeclampsia, which may begin as early as 20 weeks. While symptomatic treatment is available, the only cure is delivery of the baby and the placenta, often called the “afterbirth.”

Doctoral student Inbal Admati began to study preeclampsia after she found herself having an emergency C-section six weeks before she was scheduled to give birth due to the disease. Together with master’s student Niv Skarbianskis, she set out to study the exact placental aberrations that cause preeclampsia, collecting samples from placentas from women who have just given birth. Placentas were gathered from preterm births in otherwise healthy mothers, healthy births carried to term, women with early preeclampsia, and from women with late-onset preeclampsia. 

“We needed fresh samples for the study,” Admati said. “So sometimes I was rushing to maternity wards in the middle of the night with a cooler to immediately process them in the lab.”

The team found that the aberrations in early-onset and late-onset preeclampsia are quite different. Examining all samples on a single-cell level for the first time ever, they discovered massive dysregulation of gene expression in all cell classes that was almost exclusive to early preeclampsia. Early preeclampsia placentas also showed signs of inflammation that were absent in late-onset preeclampsia. In late-onset preeclampsia, the cells of the placenta were surprisingly almost unaffected.

Understanding the molecular changes that occur in early and late preeclampsia could open the door to early diagnosis and treatment and provide additional care to women expected to have complications.

The students worked under the supervision of Professor Amit Zeisel from the Technion Faculty of Biotechnology and Food Engineering and Dr. Ido Solt from the Ruth and Bruce Rappaport Faculty of Medicine and the Rambam Health Care Campus. The study was published in MED, the flagship journal for clinical and translational research, and funded by the Preeclampsia Foundation.