C-reactive protein and serum amyloid A protein in pregnancy and labour.

Serum levels of C-reactive protein (CRP) and amyloid A protein (SAA) were measured prospectively using immunoradiometric assays in normal pregnant women, newborn infants and women with prelabour rupture of membranes (PROM), focusing on the peripartum period. CRP levels in 50 healthy women at 38 weeks gestation did not differ significantly from previously established normal values. CRP levels in 67 healthy women sampled serially in labour from admission to 96 h postpartum confirm the physiological occurrence of a major acute phase response. The serial CRP levels of 16 women with PROM did not differ significantly from the wide range of CRP levels found in the normal postpartum period. This complicates the use of CRP as an early predictor of clinical chorio-amnionitis. Serial SAA levels in 17 women at 38 weeks gestation, immediately postpartum and 24 h postpartum showed a parallel rise to CRP in the peripartum period. Significant differences between maternal and neonatal CRP and SAA levels were demonstrated, implying a lack of transplacental transfer during labour.