[A sensitivity of CRP determination of cord blood and neonatal serum for neonatal infection].

CRP was determined for 110 cord bloods and peripheral blood of 36 newborns collected within 72 hours after delivery for the early diagnosis of newborn infection. The determination of CRP was done by a counting immunoassay method using PAMIA-30(Sysmex, Kobe, Japan). Sample volume needed was small and the time for determination was short. Within-run and between-run precisions were satisfactory, with CV values being approximately 6%. The CRP of healthy newborns was lower than that of cord blood, and the mean value was 33.4 +/- 4.2 ng/ml and the value was not significantly different from that obtained from the newborn babies with turbid amnionic fluid or early rupture of a sac. The CRP gradually increased after delivery had a peak at 24 to 48 hours after delivery. This tendency was observed both in healthy and infected newborns. The data were divided into 6 groups depending on the time collected after delivery (6, 12, 24, 48, and 72 hours). The CRP of blood from infected newborns tended to have higher CRP than that of healthy newborns in each group. Increased amount of CRP (ng/ml/hrs) was calculated as ((CRP of peripheral blood at time x)--(CRP of cord blood))/x, and this value was significantly higher (p < 0.05) in infected newborns than in healthy newborns 12hrs and more after delivery. Thus, CRP might be useful for monitoring the newborn infection.