High CRP in pregnancy linked to preterm delivery

Women who have very high levels of the inflammatory marker C-reactive protein (CRP) early in pregnancy run the risk of delivering before term, according to a study reported in American Journal of Epidemiology.

"CRP in early pregnancy has the potential to have some very useful clinical utility in predicting preterm deliveries, but we need more research to verify these results," Dr. Waranuch Pitiphat from Khon Kaen University in Thailand told Reuters Health.

CRP is a marker of a generalized ongoing inflammatory process, often due to low-grade infection.

Pitiphat, together with a Boston-based team of researchers, examined levels of CRP in blood samples obtained at roughly 5 to 19 weeks' gestation from 117 women who delivered before 37 weeks' gestation and from 117 control women who delivered at term.

The average CRP concentration was 3.2 units in those who delivered preterm versus 2.4 in those who delivered at term.

Women with very high levels - 8 units or greater early in pregnancy had a 2.5-times higher chance of having preterm delivery. The association was independent of many other factors linked to early labor.

"These findings did not come as a surprise," Pitiphat told Reuters Health, noting that " maternal inflammation and infections are known to predispose for preterm delivery. CRP is a sensitive marker of inflammation."

Therefore, the results of this study are "consistent with the hypothesis that chronic low-grade inflammation may raise CRP levels and cause preterm delivery," the investigator concluded.

SOURCE: American Journal of Epidemiology, December 2005.