Characteristics of women in preterm labor associated with elevated C-reactive protein levels

To evaluate clinical, microbiologic, and histologic findings associated with elevated C-reactive protein levels among women in preterm labor or with preterm premature rupture of the membranes (PROM).

Obstetric data, serum C-reactive protein levels, and amniotic fluid (AF) and chorioamniotic membrane cultures and histology were obtained on 203 women presenting between 22-34 weeks' gestation in preterm labor or with PROM.

Women with C-reactive protein greater than 1.5 mg/dL were more likely to deliver within 7 days of enrollment (54 of 68, 79%) than were women with normal C-reactive protein levels (45 of 135, 33%) (P < .001). The median C-reactive protein levels and association with rapid delivery did not differ between women with intact versus ruptured membranes. Elevated C-reactive protein levels were associated with a positive AF culture among women in preterm labor with intact membranes. To control for confounding by a long interval to delivery, only the group delivering within 7 days was considered for evaluation of C-reactive protein levels and placental and infant outcome. Among women delivering within 7 days, elevated C-reactive protein was associated with the development of clinical chorioamnionitis and with infant death before hospital discharge, but not with a positive membrane culture or histologic chorioamnionitis.

Elevated C-reactive protein appears to be associated with AF infection, delivery within 7 days of admission, and infant death among women delivering preterm, but not with membrane infection or inflammation. Elevated C-reactive protein may be helpful in determining the need for AF culture and in targeting studies of antibiotic therapy among women in preterm labor or with preterm PROM.