'Zombie cells' in the placenta may cause heart failure in pregnancy

"Zombie cells" lurking in the placenta may underpin a type of heart failure that strikes in late pregnancy or shortly after birth, a new study finds.

These undead cells point to potential ways to treat the poorly understood condition, known as postpartum cardiomyopathy (PPCM), which weakens the heart so it can't pump blood as efficiently. Symptoms of this type of heart failure range from mild to deadly, and it affects an estimated 1 in 1,000 live births in the U.S. and closer to 1 in 100 live births in Nigeria.

The new study, published Wednesday (April 17) in the journal Science Translational Medicine, may also shed light on biological aging — a process that appears to speed up during pregnancy, at least by some measures. 

"We do believe that there may be a link here," first study author Dr. Jason Roh, an assistant professor of medicine at Harvard Medical School and a cardiologist at Massachusetts General Hospital, told Live Science in an email.

Studies of biological aging in pregnancy have looked mostly at epigenetics — chemical tags found on top of DNA — but the new study looked at proteins made by cells in the placenta. There isn't yet direct evidence linking these two processes, but that could potentially be revealed in later research.

Related: 'Mini placentas' may reveal roots of pregnancy disorders like preeclampsia

Biological aging in the placenta

The exact cause of PPCM is a mystery, but the condition has been tied to preeclampsia, a condition involving persistent high blood pressure that emerges between midpregnancy and the postpartum period. It's well established that preeclampsia is a risk factor for this type of heart failure, but in recent years, emerging evidence has suggested that the two conditions may actually share underlying causes.