Understanding the Links Between the Placenta and Preeclampsia

Preeclampsia is a pregnancy-associated high blood pressure disorder. Although the cause of the disorder is unknown, the placenta likely plays a role, because researchers have found differences in placentas from preeclamptic pregnancies. Preeclamptic placentas often have imbalances in lipids and their inflammatory products, which also recruit and activate immune cells and change the placental environment.

Low-dose aspirin is now the standard of care for the prevention of preeclampsia in at-risk pregnant people. But some people will develop preeclampsia despite following an aspirin regimen, a situation called “aspirin failure.” Researchers supported by NICHD through the Human Placenta Project (HPP) are studying the relationship between aspirin, the placenta, and preeclampsia.

Monitoring Lipid Production

Lipids, a category of fatty acids insoluble in water, have different purposes and are found in many places in nature, including the human body. People with preeclampsia have higher levels of a lipid called thromboxane, which is associated with high blood pressure even in people who are not pregnant. Aspirin is commonly thought to reduce preeclampsia risk by preventing thromboxane synthesis and production, but HPP researchers found that low-dose aspirin also reduces a process called lipid peroxidation, which can damage cells in the placenta.

To better understand why aspirin does not always prevent preeclampsia, the researchers are studying lipids in the placenta. They undertook a comprehensive evaluation of whether lipids other than thromboxane—lipids that are not affected by aspirin—might also contribute to preeclampsia. The team also analyzed the plasma of pregnant people’s blood to see whether it was possible to identify other lipids that might be linked to preeclampsia.

Examining Non–Aspirin-Sensitive Lipids

The researchers measured numerous aspirin-sensitive and non–aspirin-sensitive lipids produced by the placenta. Abnormalities in lipids that are not sensitive to aspirin might explain why some aspirin-treated pregnant people develop preeclampsia. In one analysis, the team found significantly higher levels of non–aspirin-sensitive lipids associated with preeclampsia in pregnant people who developed severe preeclampsia and delivered preterm.

Initial Research Implications

By 22 weeks of pregnancy, study participants who would go on to develop preeclampsia had different levels of more than 25 non–aspirin-sensitive lipids than people who did not develop preeclampsia. This finding shows that a variety of lipids can influence the development of preeclampsia. It also suggests that in the future, health care providers may be able to check a person’s lipid levels early in pregnancy to identify their risk for preeclampsia later. Future research may uncover the reasons why some pregnant people have more of these lipids and may suggest ways to prevent it.

Learn more about the team

Principal Investigator(s):

Learn more about the HPP-funded project:
The utilization of photonics technology to rapidly detect bioactive lipids associated with preeclampsia development