By Aaron Wagner,Pennsylvania State University

Credit: CC0 Public Domain

Pregnant women with a history of child abuse or neglect experienced increased inflammation when exposed to mild stress compared with women without those experiences, according to a new study led by Penn State researchers. Increased inflammation, in turn, was associated with a greater number of complications during pregnancy and birth, including premature birth, according to the research team.

Inflammation is a biologically protective response: When a person gets sick or hurt, parts of the body become inflamed to stop the spread of disease or injury. Once the threat is resolved, inflammation recedes and the body returns to normal. However, inflammation sometimes persists over time, increasing the risks of heart disease, diabetes, cancer and other health problems.

"Inflammation is not just a response to physical threats," said Heidemarie Laurent, Edna Bennett Pierce Professor of Compassion and Caring at Penn State and lead author of the studypublishedinDevelopmental Psychobiology.

"Inflammation can also be triggered by psychological stress, and people who were abused or neglected as children are at greater risk of excessive inflammation due to psychological stress. In this study, we wanted to see whether a path could be traced from childhood maltreatment to stress reactivity and then forward to pregnancy outcomes."

The research team recruited 158 pregnant women in their third trimester for a laboratory visit, where they provided saliva samples. After the first sample was collected, the women were subjected to mild stress—five minutes of public speaking followed by five minutes of mental math in front of an evaluator.

After the stressful experience, participants provided four more saliva samples at 20-minute intervals. They also answered questions about their experiences with neglect and abuse as children.

The researchers analyzed the saliva samples for the presence of several markers of inflammation in the body, including C-reactive protein and interleukin-6. Because the researchers collected five samples over time, they were able to detect not only how much inflammation the women experienced but also how quickly their bodies recovered from inflammation.

Women who reported childhood maltreatment—especially those who experienced physical neglect or sexual abuse—had a higher peak inflammatory response to stress and took longer to recover.

With this connection between childhood trauma and inflammatory response to stress established, confirmingprior Penn State researchon the topic, the researchers evaluated whether there was a connection between inflammatory stress response and outcomes during pregnancy and birth.

Three months after their babies were born, 112 participants returned for a second laboratory visit. Women with higher inflammation during the first visit reported more complications during pregnancy and birth. For example, they were more likely to experience preterm birth and to have a C-section rather than a vaginal delivery.

Laurent, who is also an associate professor of human development and family studies, said the preterm birth result may be particularly important. During pregnancy, she explained, the body becomes inflamed to support the implantation of the fertilized egg and the development of the placenta during the first trimester. During the second and third trimesters, the body suppresses inflammation. When the baby is mature, the body increases inflammation again to prompt the start of labor and delivery.

"If women who have higher than normal inflammatory responses are delivering preterm babies more often, inflammation may be pushing their bodies into labor too soon," Laurent said. "More research is needed to be sure whether reducing inflammation during pregnancy could reduce preterm births."

Ultimately, Laurent said her goal is broader than reducing preterm births: She wants to find ways to stop the transmission of all stress-related disease risks from mothers to their children.

"The mother's body shapes her baby's brain and other systems," Laurent said. "If we screen women for a history of child abuse and neglect early in their pregnancies and then identify who has higher levels of inflammation—because not everyone who experiences maltreatment also experiences elevated inflammation later in life—we could pinpoint who needs extra support to reduce harmful levels of inflammation."

The researchers said mindfulness exercises are one potential tool for providing the extra support needed.

Laurent's prior researchdemonstrated that mindfulness training can help people regulate multiple stress-response systems. Laurent and her collaborators said they plan to explore whether mindfulness can help pregnant women improve their health and put their children on the path to healthy development.

More information Heidemarie K. Laurent et al, Inflammatory Stress Response During Pregnancy as a Connecting Link in Intergenerational Risk Cascades, Developmental Psychobiology (2026). DOI: 10.1002/dev.70178