Newswise — A new study shows that women who report high levels of stress and low social support during pregnancy are more likely to have increased immune system activity, which can trigger inflammatory responses and put them at risk for premature labor and preeclampsia.

These inflammatory immune system responses involve increases in two proteins — cytokines and C-reactive protein (CRP).

"Stress affects levels of serum cytokines across pregnancy," found University of Denver at Colorado researchers led by Mary Coussons-Read, Ph.D. Similarly, "psychosocial factors can affect levels of CRP in serum in mid- and late pregnancy."

The study, which appears in the latest issue of the journal Brain, Behavior, and Immunity, comprised 52 pregnant women ages 18 to 34. Once per trimester, women completed a questionnaire that measured psychological stress and social support. The women also had blood tests to measure cytokine and CRP levels.

Preeclampsia, symptoms of which include sudden increases in blood pressure, excessive weight gain and severe headaches, can affect the mother's kidney, liver and brain function. If left untreated, preeclampsia can result in seizures or even coma during pregnancy. Uncontrolled preeclampsia can threaten the life of both the mother and the baby.

"Premature labor in itself in not so bad," Coussons-Read said; rather, "premature delivery is the problem as it can have lasting effects on infant and child development." Premature infants can have health problems associated with immature lungs and other body systems, including the nervous system.

Margaret Altemus, M.D., of Weill Medical College at Cornell University, said that the timing and severity of preeclampsia or premature labor are important to outcomes for both mother and child.

"Sometimes premature labor is treated with medication, subsides, and the pregnancy goes to full term," Altemus said. "But if the premature labor continues, a baby could be born up to14 weeks early, which is very dangerous. Preeclampsia is dangerous, but if it develops late in pregnancy, the delivery can be induced and mother and baby do fine."

Brain, Behavior and Immunity: Visit

Coussons-Read ME, Okun ML, Nettles CD. Psychosocial stress increases inflammatory markers and alters cytokine production across pregnancy. Brain, Behavior, and Immunity, 21(3), 2007.

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Brain, Behavior, and Immunity